Sample records for tc generators sintesis

  1. Use of (99m)Tc from a commercial (99)Mo/(99m)Tc generator as yield tracer for the determination of (99)Tc at low levels.

    PubMed

    Hou, Xiaolin; Jensen, Mikael; Nielsen, Sven P

    2007-05-01

    The concentrations of (99)Tc and impurity radionuclides in the (99m)Tc tracer solution obtained from a commercial (99)Mo/(99m)Tc generator were measured by gamma spectrometry and liquid scintillation counting. (99)Mo and (103)Ru were found in the (99m)Tc eluate. A simple separation using two extra alumina cartridges was investigated to purify the eluate to obtain a suitable (99m)Tc tracer with low (99)Tc concentration. The activity ratio of (99)Tc/(99m)Tc in the prepared (99m)Tc solution is lower than 15 x 10(-9), which is higher than the theoretical ratio of less than 10 x 10(-9). The possible reason is discussed. The (99)Tc in the 20 kBq spiked (99m)Tc tracer was found to be less than 0.3 mBq, which is lower than the detection limit of the radiometric method used for environmental samples. The purified (99m)Tc eluate is used as yield tracer for the determination of low levels of (99)Tc in environmental samples. PMID:17350274

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

    PubMed Central

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

    2011-01-01

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

  3. 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.

  4. 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.

  5. 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.

  6. Artculo publicado en: 1 Conf. Intern. Sierra Nevada, I: 389-417. 1996 SINTESIS HIDROLOGICA DEL MACIZO DE SIERRA NEVADA

    E-print Network

    Castillo, Antonio

    Artículo publicado en: 1ª Conf. Intern. Sierra Nevada, I: 389-417. 1996 SINTESIS HIDROLOGICA DEL MACIZO DE SIERRA NEVADA (GRANADA Y ALMERIA) Castillo, A. Consejo Superior de Investigaciones Científicas-Univ. Politécnica Madrid). Ríos Rosas, 21. 28003 Madrid RESUMEN El macizo de Sierra Nevada (Granada y Almería

  7. 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.

  8. 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

  9. 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

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

    PubMed

    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

  11. Design and performance of an automated radionuclide separator: its application on the determination of ??Tc in groundwater.

    PubMed

    Chung, Kun Ho; Choi, Sang Do; Choi, Geun Sik; Kang, Mun Ja

    2013-11-01

    A modular automated radionuclide separator for (99)Tc (MARS Tc-99) has been developed for the rapid and reproducible separation of technetium in groundwater samples. The control software of MARS Tc-99 was developed in the LabView programming language. An automated radiochemical method for separating (99)Tc was developed and validated by the purification of (99m)Tc tracer solution eluted from a commercial (99)Mo/(99m)Tc generator. The chemical recovery and analytical time for this radiochemical method were found to be 96 ± 2% and 81 min, respectively. PMID:23602584

  12. 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.

  13. Effects of FlAsH/Tetracysteine (TC) tag on PrP proteolysis and PrPres formation by TC-scanning

    PubMed Central

    Taguchi, Yuzuru; Hohsfield, Lindsay A.; Hollister, Jason R.

    2014-01-01

    The FlAsH/tetracysteine (FlAsH/TC) tag is a powerful tool for fluorescent labeling of proteins. However, even small tags such as FlAsH/TC could alter the behavior of the tagged proteins, especially if the insertion occurs at internal sites. Defining the influence of FlAsH/TC on nearby protein-protein interactions might aid in selecting appropriate positions for internal TC insertions and allow the exploitation of serial FlAsH/TC insertions (TC-scanning) as a probe to characterize sites of protein-protein interaction. To explore this application in the context of substrate-protease interactions, we analyzed the effect of FlAsH/TC insertions on proteolysis of cellular prion protein (PrPsen) in in vitro reactions and generation of the C1 metabolic fragment of PrPsen in live neuroblastoma cells. The influence of FlAsH/TC insertion was evaluated by TC-scanning across the cleavage sites of each protease. The results showed that FlAsH/TC inhibited protease cleavage only within limited ranges of the cleavage sites that varied from about 1 to 6 residues-wide depending on the protease, providing an estimate of the PrP residues interacting with each protease. TC-scanning was also used to probe a different type of protein-protein interaction, the conformational conversion of FlAsH-PrPsen to the prion disease-associated isoform, PrPres. PrP constructs with FlAsH/TC insertions at residues 90–96 but not 97–101 were converted to FlAsH-PrPres, identifying a boundary separating loosely versus compactly folded regions of PrPres. Our observations demonstrate that TC-scanning with the FlAsH/TC tag can be a versatile method for probing protein-protein interactions and folding processes. PMID:23943295

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

    PubMed

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

    2014-02-01

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

  15. 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.

  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. Generation of electromagnetic waves from 0.3 to 1.6 terahertz with a high- Tc superconducting Bi2Sr2CaCu2O8+? intrinsic Josephson junction emitter

    NASA Astrophysics Data System (ADS)

    Kashiwagi, Takanari; Yamamoto, Takashi; Kitamura, Takeo; Asanuma, Kentaro; Watanabe, Chiharu; Nakade, Kurama; Yasui, Takaki; Saiwai, Yoshihiko; Shibano, Yuuki; Kubo, Hiroyuki; Sakamoto, Kazuki; Katsuragawa, Takuya; Tsujimoto, Manabu; Delfanazari, Kaveh; Yoshizaki, Ryozo; Minami, Hidetoshi; Klemm, Richard A.; Kadowaki, Kazuo

    2015-03-01

    To obtain higher power P and frequency f emissions from the intrinsic Josephson junctions in a high-Tc superconducting Bi2Sr2CaCu2O8+? single crystal, we embedded a rectangular stand-alone mesa of that material in a sandwich structure to allow for efficient heat exhaust. By varying the current-voltage (I-V) bias conditions and the bath temperature Tb, f is tunable from 0.3 to 1.6 THz. The maximum P of a few tens of ?W, an order of magnitude greater than from previous devices, was found at Tb˜55 K on an inner I-V branch at the TM(1,0) cavity resonance mode frequency. The highest f of 1.6 THz was found at Tb=10 K on an inner I-V branch, but away from cavity resonance frequencies. A possible explanation is presented.

  18. 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

  19. 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

  20. 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

    2014-04-01

    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.

  1. 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.

  2. 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.

  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. 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

  5. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2015-01-01

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

  7. 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.

  8. Oxidative dissolution potential of biogenic and abiogenic TcO 2 in subsurface sediments

    NASA Astrophysics Data System (ADS)

    Fredrickson, James K.; Zachara, John M.; Plymale, Andrew E.; Heald, Steve M.; McKinley, James P.; Kennedy, David W.; Liu, Chongxuan; Nachimuthu, Ponnusamy

    2009-04-01

    Technetium-99 (Tc) is an important fission product contaminant associated with sites of nuclear fuels reprocessing and geologic nuclear waste disposal. Tc is highly mobile in its most oxidized state [Tc(VII)O4-] and less mobile in the reduced form [Tc(IV)O 2· nH 2O]. Here we investigate the potential for oxidation of Tc(IV) that was heterogeneously reduced by reaction with biogenic Fe(II) in two sediments differing in mineralogy and aggregation state; unconsolidated Pliocene-age fluvial sediment from the upper Ringold (RG) Formation at the Hanford Site and a clay-rich saprolite from the Field Research Center (FRC) background site on the Oak Ridge Site. Both sediments contained Fe(III) and Mn(III/IV) as redox active phases, but FRC also contained mass-dominant Fe-phyllosilicates of different types. Shewanella putrefaciens CN32 reduced Mn(III/IV) oxides and generated Fe(II) that was reactive with Tc(VII) in heat-killed, bioreduced sediment. After bioreduction and heat-killing, biogenic Fe(II) in the FRC exceeded that in RG by a factor of two. More rapid reduction rates were observed in the RG that had lower biogenic Fe(II), and less particle aggregation. EXAFS measurements indicated that the primary reduction product was a TcO 2-like phase in both sediments. The biogenic redox product Tc(IV) oxidized rapidly and completely in RG when contacted with air. Oxidation, in contrast, was slow and incomplete in the FRC, in spite of similar molecular scale speciation of Tc compared to RG. X-ray microprobe, electron microprobe, X-ray absorption spectroscopy, and micro X-ray diffraction were applied to the whole sediment and isolated Tc-containing particles. These analyses revealed that non-oxidizable Tc(IV) in the FRC existed as complexes with octahedral Fe(III) within intra-grain domains of 50-100 ?m-sized, Fe-containing micas presumptively identified as celadonite. The markedly slower oxidation rates in FRC as compared to RG were attributed to mass-transfer-limited migration of O 2 into intra-aggregate and intraparticle domains where Tc(IV) existed; and the formation of unique, oxidation-resistant, intragrain Tc(IV)-Fe(III) molecular species.

  9. Adoptive Transfer of Tumor-Specific Tc17 Effector T Cells Controls the Growth of B16 Melanoma in Mice

    PubMed Central

    de la Luz Garcia-Hernandez, Maria; Hamada, Hiromasa; Reome, Joyce B.; Misra, Sara K.; Tighe, Michael P.; Dutton, Richard W.

    2010-01-01

    In vitro generated OVA-specific IL-17–producing CD8 T effector cells (Tc17) from OT-1 mice, adoptively transferred into B16-OVA tumor-bearing mice, controlled tumor growth in early and late stage melanoma. IL-17, TNF, and IFN-? from the Tc17 effectors all played a role in an enhanced recruitment of T cells, neutrophils, and macrophages to the tumor. In addition, Tc17 cells and recently recruited, activated neutrophils produced further chemokines, including CCL3, CCL4, CCL5, CXCL9, and CXCL10, responsible for the attraction of type 1 lymphocytes (Th1 and Tc1) and additional neutrophils. Neutrophils were rapidly attracted to the tumor site by an IL-17 dependent mechanism, but at later stages the induction of the chemokine CXCL2 by Tc17-derived TNF and IFN-? contributed to sustain neutrophil recruitment. Approximately 10–50 times as many Tc17 effectors were required compared with Tc1 effectors to exert the same level of control over tumor growth. The recruitment of neutrophils was more prominent when Tc17 rather than Tc1 were used to control tumor and depletion of neutrophils resulted in a diminished capacity to control tumor growth. PMID:20237297

  10. 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.

  11. Effect of the Tc-nitrido group on the behaviour of 99mTc-radiopharmaceuticals.

    PubMed

    Baldas, J; Bonnyman, J

    1985-12-01

    The preparation of the 99mTcN-complexes of gluconate, EHDP, HIDA and PIPIDA by substitution reactions of 99mTcNCl4- is described. Studies of the distribution of these complexes in mice indicate that the presence of the Tc-nitrido group significantly alters the biological properties of the 99mTc-complexes formed using these ligands. Results suggest that the 99mTcN-complexes of these ligands are labile and undergo some ligand exchange in vivo. PMID:3936786

  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. 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.

  14. 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.

  15. 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.

  16. Reinvestigation of Collective Bands in 107Tc

    NASA Astrophysics Data System (ADS)

    Gu, Long; Zhu, Sheng-Jiang; Hamilton H., J.; Ramayya V., A.; Hwang K., J.; Liu H., S.; Wang, Jian-Guo; Luo X., Y.; Rasmussen O., J.; Lee Y., I.; Ding, Huai-Bo; K., Li; Xu, Qiang; Yang, Yun-Yi

    2009-09-01

    The high spin states of a neutron-rich 107Tc nucleus are reinvestigated by observing prompt ?-rays from the spontaneous fission of 252Cf. The previous level scheme is updated. A collective band based on the ?5/2- [303] orbital is confirmed and extended. Inconsistencies in the configuration assignments for a type of positive parity bands of odd-A 105,107,109Tc in the previous reports are clarified according to the g factor calculations. A new band based on the 1499.5 keV level in 107Tc is proposed as a two-phonon ?-vibrational band.

  17. 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.

  18. Renal uptakes of 99mTc-MAG3, 99mTc-DTPA, and 99mTc-DMSA in rabbits with unilateral ureteral obstruction.

    PubMed

    Lee, Won Guk; Kim, Joong-Hyun; Kim, Jong Min; Shim, Kyung Mi; Kang, Seong Soo; Chae, Hong In; Choi, Seok Hwa

    2010-01-01

    Renal function measurements using (99m)Tc-DTPA and (99m)Tc-MAG(3) dynamic scintigraphs were compared to those obtained using (99m)Tc-DMSA static scintigraphy. Eighteen experimental rabbits were randomly divided into (99m)Tc-DTPA-, (99m)Tc-MAG(3)-, and (99m) Tc-DMSA-injected groups. Experimental unilateral renal damage was induced by ligating a unilateral right ureter in 18 rabbits. Scintigraphic images were obtained at 2 and 5 h after intravenous injection of (99m)Tc-DMSA, or immediately after administration of (99m)Tc-DTPA or (99m)Tc-MAG(3). For the dynamic images using (99m)Tc-DTPA and (99m)Tc-MAG(3), rapid sequential images were obtained every 2 s for 30 images up to 1 min. The three groups presented different relative renal functions between the left normal and the right abnormal kidneys at 1, 2, 3, and 4 weeks post-ligation (p<0.05). However, the between-group comparisons showed no significant differences at any time. These results suggest that dynamic images of (99m)Tc-DTPA and (99m)Tc-MAG(3) can be used to measure the relative renal function in place of the static image of (99m)Tc-DMSA. PMID:20363984

  19. 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

  20. PREFACE: 2014 Joint IMEKO TCTCTC13 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) TCTCTC13 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 TCTCTC13 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

  1. 2006 11 43 TC 11 175 2006-43TC-11-18

    E-print Network

    Choi, Woo-Young

    & Medical) . ZigBee * , (High speed circuit and system Lab. Yonsei University ) ** , SoC (So2006 11 43 TC 11 175 2006-43TC-11-18 ZigBee 900MHz CMOS RF ( Implementation of a CMOS RF Transceiver for 900MHz ZigBee Applications ) * , * , * , ** ( J. K. Kwon, K. Y. Park, Woo

  2. 2006 11 43 TC 11 175 2006-43TC-11-18

    E-print Network

    Choi, Woo-Young

    2006 11 43 TC 11 175 2006-43TC-11-18 ZigBee 900MHz CMOS RF ( Implementation of a CMOS RF Transceiver for 900MHz ZigBee Applications ) * , * , * , ** ( J. K. Kwon, K. Y. Park, Woo-Young Choi, and W. S. Oh ) ZigBee 900MHz ISM RF . , , , , , , , . Low

  3. A Monoallelic Deletion of the TcCRT Gene Increases the Attenuation of a Cultured Trypanosoma cruzi Strain, Protecting against an In Vivo Virulent Challenge

    PubMed Central

    Sánchez-Valdéz, Fernando J.; Pérez Brandán, Cecilia; Ramírez, Galia; Uncos, Alejandro D.; Zago, M. Paola; Cimino, Rubén O.; Cardozo, Rubén M.; Marco, Jorge D.; Ferreira, Arturo; Basombrío, Miguel Ángel

    2014-01-01

    Trypanosoma cruzi calreticulin (TcCRT) is a virulence factor that binds complement C1, thus inhibiting the activation of the classical complement pathway and generating pro-phagocytic signals that increase parasite infectivity. In a previous work, we characterized a clonal cell line lacking one TcCRT allele (TcCRT+/?) and another overexpressing it (TcCRT+), both derived from the attenuated TCC T. cruzi strain. The TcCRT+/? mutant was highly susceptible to killing by the complement machinery and presented a remarkable reduced propagation and differentiation rate both in vitro and in vivo. In this report, we have extended these studies to assess, in a mouse model of disease, the virulence, immunogenicity and safety of the mutant as an experimental vaccine. Balb/c mice were inoculated with TcCRT+/? parasites and followed-up during a 6-month period. Mutant parasites were not detected by sensitive techniques, even after mice immune suppression. Total anti-T. cruzi IgG levels were undetectable in TcCRT+/? inoculated mice and the genetic alteration was stable after long-term infection and it did not revert back to wild type form. Most importantly, immunization with TcCRT+/? parasites induces a highly protective response after challenge with a virulent T. cruzi strain, as evidenced by lower parasite density, mortality, spleen index and tissue inflammatory response. TcCRT+/? clones are restricted in two important properties conferred by TcCRT and indirectly by C1q: their ability to evade the host immune response and their virulence. Therefore, deletion of one copy of the TcCRT gene in the attenuated TCC strain generated a safe and irreversibly gene-deleted live attenuated parasite with high immunoprotective properties. Our results also contribute to endorse the important role of TcCRT as a T. cruzi virulence factor. PMID:24551259

  4. A monoallelic deletion of the TcCRT gene increases the attenuation of a cultured Trypanosoma cruzi strain, protecting against an in vivo virulent challenge.

    PubMed

    Sánchez-Valdéz, Fernando J; Pérez Brandán, Cecilia; Ramírez, Galia; Uncos, Alejandro D; Zago, M Paola; Cimino, Rubén O; Cardozo, Rubén M; Marco, Jorge D; Ferreira, Arturo; Basombrío, Miguel Ángel

    2014-02-01

    Trypanosoma cruzi calreticulin (TcCRT) is a virulence factor that binds complement C1, thus inhibiting the activation of the classical complement pathway and generating pro-phagocytic signals that increase parasite infectivity. In a previous work, we characterized a clonal cell line lacking one TcCRT allele (TcCRT+/-) and another overexpressing it (TcCRT+), both derived from the attenuated TCC T. cruzi strain. The TcCRT+/- mutant was highly susceptible to killing by the complement machinery and presented a remarkable reduced propagation and differentiation rate both in vitro and in vivo. In this report, we have extended these studies to assess, in a mouse model of disease, the virulence, immunogenicity and safety of the mutant as an experimental vaccine. Balb/c mice were inoculated with TcCRT+/- parasites and followed-up during a 6-month period. Mutant parasites were not detected by sensitive techniques, even after mice immune suppression. Total anti-T. cruzi IgG levels were undetectable in TcCRT+/- inoculated mice and the genetic alteration was stable after long-term infection and it did not revert back to wild type form. Most importantly, immunization with TcCRT+/- parasites induces a highly protective response after challenge with a virulent T. cruzi strain, as evidenced by lower parasite density, mortality, spleen index and tissue inflammatory response. TcCRT+/- clones are restricted in two important properties conferred by TcCRT and indirectly by C1q: their ability to evade the host immune response and their virulence. Therefore, deletion of one copy of the TcCRT gene in the attenuated TCC strain generated a safe and irreversibly gene-deleted live attenuated parasite with high immunoprotective properties. Our results also contribute to endorse the important role of TcCRT as a T. cruzi virulence factor. PMID:24551259

  5. 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.

  6. 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.

  7. 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.

  8. Varicella-zoster virus-specific cytotoxic T lymphocytes (Tc): detection and frequency analysis of HLA class I-restricted Tc in human peripheral blood.

    PubMed Central

    Hickling, J K; Borysiewicz, L K; Sissons, J G

    1987-01-01

    The cytotoxic T-cell (Tc) response to varicella-zoster virus (VZV) is incompletely characterized. We investigated whether VZV-specific Tc restricted by class I products of the major histocompatibility complex can be generated from the peripheral blood of VZV-immune donors. Cell lines were established from peripheral blood lymphocytes (PBL) of seropositive donors by secondary in vitro restimulation. If cell-free VZV was used as the stimulating antigen, the resulting lines were predominantly CD4+ and did not show class I-restricted cytotoxicity; when autologous infected fibroblasts were used for in vitro stimulation, the resultant lines were usually cytotoxic, although in only 4 of 11 subjects tested was this cytotoxicity HLA restricted and virus specific. PBL were also tested for Tc activity without prior restimulation; VZV-specific Tc activity was only demonstrable in the PBL of a subject convalescent following zoster but not from subjects with recent varicella infection or from normal subjects. VZV-specific Tc precursor frequencies were then determined in six selected subjects by limiting-dilution analysis. A measurable frequency was detectable in four of the six seropositive subjects, ranging from 11/10(6) T cells in an asymptomatic carrier, to 63/10(6) T cells in a subject with recent zoster. We conclude that virus-specific major histocompatibility complex class I-restricted Tc precursors may be present in the peripheral blood of normal individuals seropositive for VZV but at a frequency lower than that for other herpesviruses with nonneuronal sites of latency. PMID:2822954

  9. Amyloidosis of heart and liver: comparison of Tc-99m pyrophosphate and Tc-99m methylene diphosphonate for detection

    SciTech Connect

    Lee, V.W.; Caldarone, A.G.; Falk, R.H.; Rubinow, A.; Cohen, A.S.

    1983-07-01

    A prospective, comparative study was made of the efficacy of technetium-99m pyrophosphate (Tc PYP) and technetium-99m methylene diphosphonate (Tc MDP) in detecting soft-tissue amyloidois. Tc PYP and Tc MDP scans were obtained within ten-day intervals in seven patients with histologically proven amyloidosis. Tc PYP was a better scanning agent for soft-tissue amyloidosis in all patients. Cardiac and hepatic involvement were proved by autopsy in one patient. Involvement of the heart was confirmed by echocardiography in five patients. The potential use of tc PYP scannning as a screening test for soft-tissue amyloidosis is discussed.

  10. TC IN / OUT (Based on 30fps)

    E-print Network

    TC IN / OUT (Based on 30fps) Tornado Alley Transcription 01:00:54:00 to 01:01:12:00 NARRATOR:02:47:00 NARRATOR: Tornado Alley is a name well earned, for it is home to nearly 80% of the world's most violent tornadoes. The destruction they leave behind each year is enormous ­ and the human toll is no less

  11. Adolescent Services & the TC. Chapter 6.

    ERIC Educational Resources Information Center

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

    This document contains seven papers from the ninth World Conference of Therapeutic Communities (TCs) that deal with adolescent clients and TCs. Papers include: (1) Preliminary Consideration on "Adolescence and the TC" (David Deitch); (2) "Daytop's Full Service Adolescent Treatment Program" (Charles Devlin and Lois Morris); (3) "Adolescent…

  12. 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…

  13. 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.

  14. 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.

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

    SciTech Connect

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

    1984-05-01

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

  16. Co-Culture of ? TC-6 Cells and ? TC-1 Cells: Morphology and Function

    PubMed Central

    Kim, Sung Man; Lee, Eun Ju; Jung, Hye Sook; Han, Na; Kim, You Jeong; Kim, Tae Kyoon; Kim, Tae Nyun; Kwon, Min Jeong; Lee, Soon Hee; Park, Jeong Hyun; Rhee, Byoung Doo

    2015-01-01

    Background In vitro experiments using only ?-cell lines instead of islets are limited because pancreatic islets are composed of four different types of endocrine cells. Several recent studies have focused on cellular interactions among these cell types, especially ?- and ?-cells. Because islet isolation needs time and experience, we tested a simple co-culture system with ?- and ?-cells. Their morphology and function were assessed by comparison to each single cell culture and pancreatic islets. Methods ? TC-6 cells and ? TC-1 cells were maintained in Dulbecco's Minimal Essential Medium containing 5 mM glucose and 10% fetal bovine serum. Cells were mixed at a 1:1 ratio (5×105) in 6-well plates and cultured for 24, 48, and 72 hours. After culture, cells were used for insulin and glucagon immunoassays and tested for glucose-stimulated insulin secretion (GSIS). Results ? TC-6 and ? TC-1 cells became condensed by 24 hours and were more strongly compacted after 48 hours. ? TC-1 cells showed both ?-? and ?-? cell contacts. GSIS increased with increasing glucose concentration in co-cultured cells, which showed lower secreted insulin levels than ? TC-1 cells alone. The increase in the secreted insulin/insulin content ratio was significantly lower for co-cultured cells than for ?-cells alone (P=0.04). Compared to islets, the ?-/?-cell co-culture showed a higher ratio of GSIS to insulin content, but the difference was not statistically significant (P=0.09). Conclusion ? TC-6 and ? TC-1 cells in the co-culture system showed cell-to-cell contacts and a similar stimulated insulin secretion pattern to islets. The co-culture system may be used to better mimic pancreatic islets in in vitro assessments. PMID:25325280

  17. 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

  18. [Radionuclide purity of 99mTC eluate for use in nuclear medicine].

    PubMed

    Vucina, J L

    1996-01-01

    The radionuclide purity of 99mTc eluates obtained by the elution on the commercially available 99Mo/99mTc generators based of fission-produced 99Mo was determined by gamma spectrometry. The following parameters were determined: the content of radionuclide impurities and their distribution in the eluates during the 10 days elution of the generator. The main radiocontaminant is 99Mo. In all eluates three long-living gamma emitters 103Ru, 106Ru and 131I were found. 125Sb appears only in the first three eluates. After that its activity falls under the detection limit. These four radioisotopes are fission products. They are formed in the fission of 235U and follow 99Mo during the separation and purification steps. It was found that the highest activity in eluates is due to the presence of 103Ru. By comparison of the obtained results and the prescribed criteria of the radio-nuclide purity of 99mTc eluates it could be concluded that all the found radionuclide impurities are under the permitted levels. Therefore 99mTc eluates fulfill the criteria for the nuclear-medical applications. PMID:8643069

  19. Comparison of Tc99m MDP, Tc99m HSA and Tc99m HIG uptake in rheumatoid arthritis and its variants

    Microsoft Academic Search

    Murathan Sahin; Irem Bernay; Tarik Basoglu; Ferhan Canturk

    1999-01-01

    Tc-99m polyclonal immunoglobulin-G has been shown to be a successful agent in the depiction of active inflammation in rheumatoid\\u000a arthritis (RA). The objective of this study was to compare the uptake behaviors of Tc-99m HIG and Tc-99m MDP in RA and variants\\u000a of rheumatoid arthritis (VRA). Seventeen patients with RA and 8 patients with VRA presenting with active inflammation were

  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. High Tc SQUID systems for magnetophysiology

    NASA Astrophysics Data System (ADS)

    Tarte, E. J.; Magnelind, P. E.; Tzalenchuk, A. Ya; Lõhmus, A.; Ansell, D. A.; Blamire, M. G.; Ivanov, Z. G.; Dyball, R. E.

    2002-03-01

    Magnetophysiology is the use of a superconducting quantum interference device (SQUID) based instrument to detect neuromagnetic fields evoked by electrical stimulation of brain tissue slices. In this paper we show that a SQUID based on high temperature superconductors (HTSs) would have considerable advantages over a low Tc device in this application. We construct a model of electrical activity in a hippocampal brain slice, which enables the neuromagnetic field to be determined as a function of position and distance from the tissue. We then describe the design of HTS SQUID systems for magnetophysiology and the two styles of system we are developing. Finally we use our model to show that an existing HTS SQUID magnetometer would give a superior signal to noise ratio compared to a low Tc system for the hippocampal brain slice preparation at least.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. Fe(II)- and Sulfide-Facilitated Reduction of 99Tc(VII)O4- in Microbially Reduced Hyporheic Zone Sediments

    SciTech Connect

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

    2014-07-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2014-07-01

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

  8. 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.

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

    SciTech Connect

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

    2007-07-01

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

  10. Interdecadal variation of TC frequency in Japan

    NASA Astrophysics Data System (ADS)

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

    2014-07-01

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

  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. Comparison of the tumor-seeking agent Tc-99m(V) dimercaptosuccinic acid and the renal imaging agent Tc-99m dimercaptosuccinic acid in humans

    SciTech Connect

    Ohta, H.; Ishii, M.; Yoshizumi, M.; Endo, K.; Sakahara, H.; Nakajima, T.; Yomoda, I.; Masuda, H.; Horiuchi, K.; Hata, N.

    1985-03-01

    Being aware of the ideal nuclear properties of Tc-99m, interest has been focused on the design of the (+5) oxidation state Tc-99m(V) dimercaptosuccinic acid (Tc(V)-DMSA) as a tumor-seeking agent. Tc-99m(V) DMSA holds a TcO4(3-) core and, like PO4(3-), has excellent characteristics for tumor uptake, but has a different distribution than the well-known renal scanning agent, Tc-99m DMSA. The differences in chemical behavior of Tc-99m(V) DMSA and Tc-99m DMSA are discussed. Three cases in which neoplasms were studied with Tc-99m(V) DMSA and Tc-99m DMSA are presented. Tc-99m DMSA and Tc-99m(V) DMSA, having a common ligand and tracer but, with the metal ion core in a different oxidation state, the uptake characteristics are altered markedly.

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

    Microsoft Academic Search

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

    2011-01-01

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

  14. 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.

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

    E-print Network

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

    2011-01-01

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

  16. Shape coexistence and isomeric states in neutron-rich {sup 112}Tc and {sup 113}Tc

    SciTech Connect

    Bruce, A. M.; Lalkovski, S.; Denis Bacelar, A. M. [School of Computing, Engineering and Mathematics, University of Brighton, Brighton BN2 4GJ (United Kingdom); Gorska, M.; Bednarczyk, P.; Caceres, L.; Geissel, H.; Gerl, J.; Kojouharov, I.; Kurz, N.; Prokopowicz, W.; Schaffner, H.; Tashenov, S.; Wollersheim, H. J. [Gesellschaft fuer Schwerionenforschung mbH, Planckstrasse 1, D-64291 Darmstadt (Germany); Pietri, S. [Gesellschaft fuer Schwerionenforschung mbH, Planckstrasse 1, D-64291 Darmstadt (Germany); Department of Physics, University of Surrey, Guildford GU2 7XH (United Kingdom); Podolyak, Zs.; Walker, P. M.; Cullen, I. J.; Farrelly, G. F.; Garnsworthy, A. B. [Department of Physics, University of Surrey, Guildford GU2 7XH (United Kingdom)

    2010-10-15

    Isomeric states in {sup 112}Tc and {sup 113}Tc, with half-lives of 150(17) ns and 500(100) ns, respectively, have been observed following the relativistic fission of {sup 238}U. The fission fragments have been separated in a fragment separator and identified by means of energy-loss and time-of-flight techniques. In both nuclei, the ground-state configuration is calculated to have an oblate shape and the isomerism is proposed to arise due to transitions from a triaxial excited state to a low-lying oblate state.

  17. A Meteorological Overview of the TC4 Mission

    NASA Technical Reports Server (NTRS)

    Pfister, L.; Selkirk, H. B.; Starr, D. O.; Rosenlof, K.; Newman, P. F.

    2010-01-01

    The TC4 mission in Central America during summer 2007 examined convective transport into the tropical Upper Troposphere/Lower Stratosphere (UTLS) and the evolution of cirrus clouds. The tropical tropopause layer (TTL) circulation is dominated by the Asian monsoon anticyclone and westward winds that stretch from the western Pacific into the Atlantic. During TC4, TTL westward flow over Central America was stronger than normal. Incidence of cold clouds over the Central American region was the third lowest out of 34 years sampled. The major factor was an incipient La Nina, specifically anomalously cold temperatures off the Pacific Coast of South America. Weakness in the low level Caribbean jet caused a shift in the coldest clouds from the Caribbean to the Pacific side of Central America. The character of tropopause temperature variability was that of upward propagating waves generated by local and nonlocal convection. These waves produced tropopause temperature variations of 3 K, with peak-to-peak variations of 8 K. At low levels in Central America, flow from the Sahara desert predominated; further south, the air came from the Amazon region. Convectively influenced air in the upper troposphere came from Central America, the northern Amazon region, the Atlantic ITCZ, and the North American monsoon. In the TTL, Asian and African convection affected the observed air masses. North of 10N in the Central American TTL, African and Asian convection may have contributed as much to the air masses as Central and South American convection. South of 8N, Asian and African convection had far less impact.

  18. 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.

  19. A giant nucleopore protein that binds Ran\\/TC4

    Microsoft Academic Search

    N. Yokoyama; N. Hayashi; T. Seki; N. Panté; T. Ohba; K. Nishii; K. Kuma; T. Hayashida; T. Miyata; U. Aebi; M. Fukui; T. Nishimoto

    1995-01-01

    RAN\\/TC4 is a small nuclear G protein1 that forms a complex with the chromatin-bound guanine nucleotide release factor RCC1 (ref. 2). Loss of RCC1 causes defects in cell cycle progression3,4, RNA export5-7 and nuclear protein import8. Some of these can be suppressed by overexpression of Ran\\/TC4 (ref. 1), suggesting that Ran\\/TC4 functions downstream of RCC1. We have searched for proteins

  20. Mechanism of Tc toxin action revealed in molecular detail.

    PubMed

    Meusch, Dominic; Gatsogiannis, Christos; Efremov, Rouslan G; Lang, Alexander E; Hofnagel, Oliver; Vetter, Ingrid R; Aktories, Klaus; Raunser, Stefan

    2014-04-01

    Tripartite Tc toxin complexes of bacterial pathogens perforate the host membrane and translocate toxic enzymes into the host cell, including in humans. The underlying mechanism is complex but poorly understood. Here we report the first, to our knowledge, high-resolution structures of a TcA subunit in its prepore and pore state and of a complete 1.7 megadalton Tc complex. The structures reveal that, in addition to a translocation channel, TcA forms four receptor-binding sites and a neuraminidase-like region, which are important for its host specificity. pH-induced opening of the shell releases an entropic spring that drives the injection of the TcA channel into the membrane. Binding of TcB/TcC to TcA opens a gate formed by a six-bladed ?-propeller and results in a continuous protein translocation channel, whose architecture and properties suggest a novel mode of protein unfolding and translocation. Our results allow us to understand key steps of infections involving Tc toxins at the molecular level. PMID:24572368

  1. High spin states in neutron-rich 106Tc nucleus

    NASA Astrophysics Data System (ADS)

    Gu, Long; Zhu, Sheng-Jiang; Hamilton H., J.; Ramayya V., A.; Hwang K., J.; Luo X., Y.; Rasmussen O., J.; K., Li; Lee Y., I.; Xu, Qiang; Che, Xing-Lai; Wang, Jian-Guo; Ding, Huai-Bo; Yang, Yun-Yi

    2009-03-01

    The high spin states of the neutron-rich odd-odd 106Tc nucleus have been reinvestigated by observing prompt ?-rays from the spontaneous fission of 252Cf. A previously known collective band is confirmed and expanded, and a new collective band is newly identified. Several levels in previous report in 106Tc are reexamined and they belong to the members of a band in 107Tc. The total Routhian surface (TRS) calculations show that the 106Tc has triaxial shape. The spins and parities as well as the configurations for these bands have been tentatively assigned according to the analysis of the angular momentum alignments.

  2. 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

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

    SciTech Connect

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

    1991-01-01

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

  4. 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

  5. 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

  6. Cytological effects of Tc on young soybean plants

    SciTech Connect

    Neel, J.W.; Onasch, M.A. (San Diego State Univ., CA (USA))

    1989-08-01

    Soybean seedlings (Glycine max cv. Williams) were exposed for 24 to 67 h to {sup 99}TcO{sub 4}- (Tc) at various concentrations in dilute culture solution. Reduced primary leaf midrib length was observed with 67-h exposures to greater than or equal to 6.0 mu M Tc. Cellular effects were consistently observed by a light microscope after 43-h or longer exposure to 6.6 microM Tc and higher concentrations. At lower Tc levels, abnormal cells were interspersed among cells of normal appearance. Abnormal cells displayed blockshaped nuclei which were more densely stained by Harris' hematoxylineosin Y than controls; such cells frequently demonstrated incipient plasmolysis. The number of affected cells increased with dose; both nuclei and cytoplasm demonstrated greater staining intensity and more severe plasmolysis at higher levels. At levels of greater than or equal to 13.2 Tc, cellular damage was extensive. Cells were reduced in size and were highly plasmolysed; cell walls were distorted, and intercellular spaces were reduced or became nonexistent. Mitotic activity was observed at Tc levels less than or equal to 9.9 microM. Observed Tc cellular effects are attributed principally to the alteration of membrane permeability characteristics.

  7. 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.

  8. Description of the TC 125 aboard the Mercury simulator

    NASA Technical Reports Server (NTRS)

    1979-01-01

    Two distinct phases of the TC.125 aboard the Mercury Simulator were described to pilots at a meeting in 1979. A three hour "hand on" phase, during which the pilot learns to use the system, and second; a two hour evaluation phase, during which the pilot analyzes the TC.125 and pratices making typical approaches are presented.

  9. Superconducting fluctuations and large diamagnetism of low-Tc nanoparticles

    NASA Astrophysics Data System (ADS)

    Imry, Yoseph

    2015-03-01

    It is shown that nanoparticles made of very low-Tc superconductors have a large diamagnetic response at temperatures several orders of magnitude above Tc. Most of the features of the recently observed giant diamagnetism of Au nanorods are explained in terms of superconducting fluctuations, except for the huge magnitude of the effect.

  10. A Tc-99m labeled laminin derived peptide, Tc-99m-YIGSR for thrombus specific imaging

    SciTech Connect

    Wang, G.J.; Oster, Z.H.; Som, P. [Brookhaven National Lab., Upton, NY (United States)] [and others

    1994-05-01

    Laminin derived adhesive peptides were studied as potential agents for thrombus specific imaging. Using a novel peptide Tc-99m labeling method studies were performed in vitro using human whole blood clots and platelets, and in vivo scintigraphy in animals with experimental thrombi. Aliquots of 0.1 ml human blood were placed in inclined Petri dishes until clot was well formed. Clots were rinsed 3x with phosphate buffer and 10 {mu}Ci Tc-99m YIGSR II was added. After incubation at room temperature for 1 hr, clots were again washed 3x. Residual activity was measured. Platelets were harvested using routine methods and incubated with Tc-99m YIGSR II, washed and assayed. Blocking experiments using cold YIGSR II showed that the Tc-99m labeled peptide preparation YIGSR II binds specifically and selectively to clot and platelets as compared to control experiments using nonspecific human Tc-99m IgG. Tissue distribution studies showed rapid blood clearance, urinary excretion and to a lesser degree GI tract excretion. Tc-99m YIGSR II was lower in all organs except kidneys compared to Tc-99m 50 H.19, Tc-99m IgG and Tc-99m YIGSR I. Tc-99m-YIGSR II consistently visualized thrombi within 30 min p.i. In vivo scintigraphic (thrombus/contralateral side) ratio was 3:1 and ex vivo direct counting (thrombosed to nonthrombosed vessel segment) was 5.4: 1. Compared to monoclonal antibodies peptide preparations are non- or minimally immunogenic, preparation is probably less expensive and there is also less danger of viral DNA contamination. These considerations and our data indicate that the Tc-99m-YIGSR II peptide has significant potential as a thrombus imaging agent.

  11. 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.

  12. Quantitative index calculated by 99mTc-GSA scintigraphy

    PubMed Central

    Shiraishi, Shinya; Tsuda, Noriko; Sakamoto, Fumi; Tomiguchi, Seiji; Yamashita, Yasuyuki

    2014-01-01

    99mTc-galactosyl human serum albumin (GSA) scintigraphy is useful to evaluate hepatic function and hepatic functional reserve. A reliable SPECT and CT integrated system is now commercially available. Using this system, we can obtain 99mTc-GSA SPECT/CT fused imaging with a small registration error. Therefore, the 99mTc-GSA scintigraphy techniques prove more useful in clinical practice than have been previously reported. In the latest Annals of Surgical Oncology on Oct 2014, the uptake index (UI) values calculated from 99mTc-GSA scintigraphy are reported to be useful for predicting the functional reserve of the future remnant liver. In this paper, we describe the usefulness of 99mTc-GSA scintigraphy as well as some cautions that are necessary as regards using the system. PMID:25561759

  13. Nuclear quadrupole moment of the {sup 99}Tc ground state

    SciTech Connect

    Errico, Leonardo [Departamento de Fisica and Instituto de Fisica La Plata (IFLP, CCT-La Plata, CONICET-UNLP), Facultad de Ciencias Exactas, Universidad Nacional de La Plata, Casilla de Coreo 67, 1900 La Plata (Argentina); Universidad Nacional del Noroeste Bonaerense (UNNOBA), Monteagudo 2772, 2700 Pergamino (Argentina); Darriba, German; Renteria, Mario [Departamento de Fisica and Instituto de Fisica La Plata (IFLP, CCT-La Plata, CONICET-UNLP), Facultad de Ciencias Exactas, Universidad Nacional de La Plata, Casilla de Coreo 67, 1900 La Plata (Argentina); Tang Zhengning [Bayerisches Geoinstitut, Universitaet Bayreuth, DE-95440 Bayreuth (Germany); Emmerich, Heike [Computational Materials Engineering (CME), Institute for Minerals Engineering (GHI), Center for Computational Engineering Science - CCES and Juelich-Aachen Research Alliance - JARA, RWTH Aachen University, DE-52064 Aachen (Germany); Cottenier, Stefaan [Computational Materials Engineering (CME), Institute for Minerals Engineering (GHI), Center for Computational Engineering Science - CCES and Juelich-Aachen Research Alliance - JARA, RWTH Aachen University, DE-52064 Aachen (Germany) and Instituut voor Kern-en Stralingsfysica and INPAC, Katholieke Universiteit Leuven, Celestijnenlaan 200 D, BE-3001 Leuven (Belgium)

    2008-05-15

    By combining first-principles calculations and existing nuclear magnetic resonance (NMR) experiments, we determine the quadrupole moment of the 9/2{sup +} ground state of {sup 99}Tc to be (-)0.14(3)b. This confirms the value of -0.129(20)b, which is currently believed to be the most reliable experimental determination, and disagrees with two earlier experimental values. We supply ab initio calculated electric-field gradients for Tc in YTc{sub 2} and ZrTc{sub 2}. If this calculated information would be combined with yet to be performed Tc-NMR experiments in these compounds, the error bar on the {sup 99}Tc ground state quadrupole moment could be further reduced.

  14. DNA binding activities of the Caenorhabditis elegans Tc3 transposase.

    PubMed Central

    Colloms, S D; van Luenen, H G; Plasterk, R H

    1994-01-01

    Tc3 is a member of the Tc1/mariner family of transposable elements. All these elements have terminal inverted repeats, encode related transposases and insert exclusively into TA dinucleotides. We have studied the DNA binding properties of Tc3 transposase and found that an N-terminal domain of 65 amino acids binds specifically to two regions within the 462 bp Tc3 inverted repeat; one region is located at the end of the inverted repeat, the other is located approximately 180 bp from the end. Methylation interference experiments indicate that this N-terminal DNA binding domain of the Tc3 transposase interacts with nucleotides on one face of the DNA helix over adjacent major and minor grooves. Images PMID:7838706

  15. Lamivudine (3TC) approved for combination use with AZT.

    PubMed

    James, J S

    1995-12-01

    The Food and Drug Administration (FDA) used accelerated approval regulations to approve the use of Glaxo-Wellcome's lamivudine (Epivir/3TC) in combination with AZT. The FDA guidelines used for approval, including viral load and CD4 count benefits, are explained. The guidelines warn that 3TC should be used with extreme caution in pediatric patients who are at risk of developing pancreatitis. Glaxo Wellcome has been commended for testing the drug on children beyond the FDA requirements. Cross resistance to ddI and ddC is a concern if AZT is used after 3TC treatment. Despite controversy at the Antiviral Drugs Advisory Committee meeting, the FDA did not indicate any specific T-cell range for the 3TC/AZT combination therapy. The price of 3TC to wholesalers is $3.11 per 150 mg tablet. Glaxo-Wellcome will provide reimbursement assistance to patients who have no other means of purchasing the drug. PMID:11363049

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

    PubMed

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

    1994-09-28

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

  17. The recovery of asteroid 2008 TC3

    NASA Astrophysics Data System (ADS)

    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.

    2010-10-01

    On October 7, 2008, asteroid 2008 TC3 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 × 7 km area. Meteorites fell along the track at 1.3 kg km-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-3, some of an anomalous (porous, high in carbon) polymict ureilite variety with densities as low as 1.5 g cm-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 TC3. 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.

  18. An unconventional method for measuring the Tc L3-edge of technetium compounds.

    PubMed

    Blanchard, Peter E R; Reynolds, Emily; Kennedy, Brendan J; Ling, Chris D; Zhang, Zhaoming; Thorogood, Gordon; Cowie, Bruce C C; Thomsen, Lars

    2014-11-01

    Tc L3-edge XANES spectra have been collected on powder samples of SrTcO3 (octahedral Tc(4+)) and NH4TcO4 (tetrahedral Tc(7+)) immobilized in an epoxy resin. Features in the Tc L3-edge XANES spectra are compared with the pre-edge feature of the Tc K-edge as well as other 4d transition metal L3-edges. Evidence of crystal field splitting is obvious in the Tc L3-edge, which is sensitive to the coordination number and oxidation state of the Tc cation. The Tc L3 absorption edge energy difference between SrTcO3 (Tc(4+)) and NH4TcO4 (Tc(7+)) shows that the energy shift at the Tc L3-edge is an effective tool for studying changes in the oxidation states of technetium compounds. The Tc L3-edge spectra are compared with those obtained from Mo and Ru oxide standards with various oxidation states and coordination environments. Most importantly, fitting the Tc L3-edge to component peaks can provide direct evidence of crystal field splitting that cannot be obtained from the Tc K-edge. PMID:25343795

  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 TC20

    SciTech Connect

    Southern Company Services

    2006-09-30

    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 the Transport Gasifier following significant modifications of the gasifier configuration. This demonstration took place during test campaign TC20, occurring from August 8 to September 23, 2006. The modifications proved successful in increasing gasifier residence time and particulate collection efficiency, two parameters critical in broadening of the fuel operating envelope and advancing gasification technology. The gasification process operated for over 870 hours, providing the opportunity for additional testing of various gasification technologies, such as PCD failsafe evaluation and sensor development.

  1. 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.

  2. A novel propulsion method for high- Tc superconducting maglev vehicle

    NASA Astrophysics Data System (ADS)

    Ma, Guangtong; Wang, Jiasu; Wang, Suyu; Liu, Minxian; Jing, Hua; Lu, Yiyun; Lin, Qunxu

    2008-01-01

    High-Tc superconducting (HTS) maglev is considered as a perfect transportation type because of its unique inherent stability. A direct current (DC) linear motor using the permanent magnet guideway (PMG) as the stator and the on-board coil as the rotor instead of the present inductive or synchronous alternate current (AC) linear motor which has an economic disadvantage due to the necessity to lay primary coil along the guideway is proposed in this paper. In order to modulate the magnetic field under the PMG, an inverse E shape ferromagnetic device (IESFD) core is designed. The possible winding method for the on-board coil is listed, and the analytical result shows that a considerable net ampere force and thus the propulsion force can be generated by this special structure. The influence of the concentrated effect of the IESFD on the maglev performance of HTS bulk is studied by a numerical program, and the results show that the levitation force with the IESFD is 90% of that without. It is also indicated that the load capability and lateral performance of the maglev vehicle combined this propulsion method can be improved thanks to the attractive effect between the IESFD and PMG. The cost of the HTS maglev vehicle will be remarkably reduced and then shorten the distance to practical application with this propulsion method.

  3. 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

  4. Interactions of Tc(IV) with humic substances

    SciTech Connect

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

    2011-01-01

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

  5. Nontumorous decrease in Tc-99m GSA accumulation.

    PubMed

    Akaki, S; Kanazawa, S; Tsunoda, M; Okumura, Y; Togami, I; Kuroda, M; Takeda, Y; Hiraki, Y

    2000-12-01

    Nontutimorous decrease in 99mTc-GSA accumulation has not been well covered in the literature. Understanding of this phenomenon is, however, essential for accurate evaluation of regional hepatic function. Scintigrams (transaxial SPECT) of 269 patients who underwent 99mTc-GSA liver scintigraphy were reviewed for the presence of nontumorous decreases in 99mTc-GSA accumulation. Nontumorous decreases in 99mTc-GSA accumulation were seen in 32 of 269 patients (12%). In 16 of the 32 patients (6%), nontumorous decreases in 99mTc-GSA accumulation corresponded to regional decrease in portal venous flow. The causes of such decrease in portal venous flow were portal thrombus of hepatocellular carcinomas in eight patients, portal venous stenosis or occlusion by hilar cholangiocarcinomas in five patients, inter alia. In eight patients (3%), the regions with decreased 99mTc-GSA accumulation correlated with massive hepatic necrosis in fulminant hepatitis, scar in hepatitis, or confleuent in portal venous flow, lobar biliary stasis, or both. In four patients (1.5%), the exact causes of nontumorous decrease in 99mTc-GSA accumulation could not be determined. PMID:11210101

  6. The Effect of Internally Generated Inner-Core Asymmetries on Tropical Cyclone Potential Intensity

    Microsoft Academic Search

    Bo Yang; Yuqing Wang; Bin Wang

    2007-01-01

    In a quiescent environment on an f plane, the internal dynamic processes of a tropical cyclone (TC) can generate axially asymmetric circulations (asymmetries) in its inner-core region. The present study investi- gates how these inner-core asymmetries affect TC intensity. For this purpose, a three-dimensional (3D) TC model and its axisymmetric (2D) version were used. Both have identical model vertical structure

  7. Quantitative simultaneous 99mTc/123I cardiac SPECT using MC-JOSEM.

    PubMed

    Ouyang, Jinsong; Zhu, Xuping; Trott, Cathryn M; El Fakhri, Georges

    2009-02-01

    Simultaneous rest 99mTc-Sestamibi/ 123I-BMIPP cardiac SPECT imaging has the potential to replace current clinical 99mTc-Sestamibi rest/stress imaging and therefore has great potential in the case of patients with chest pain presenting to the emergency department. Separation of images of these two radionuclides is difficult, however, because their emission energies are close. The authors previously developed a fast Monte Carlo (MC)-based joint ordered-subset expectation maximization (JOSEM) iterative reconstruction algorithm (MC-JOSEM), which simultaneously compensates for scatter and cross talk as well as detector response within the reconstruction algorithm. In this work, the authors evaluated the performance of MC-JOSEM in a realistic population of 99mTc/123I studies using cardiac phantom data on a Siemens e.cam system using a standard cardiac protocol. The authors also compared the performance of MC-JOSEM for estimation tasks to that of two other methods: standard OSEM using photopeak energy windows without scatter correction (NSC-OSEM) and standard OSEM using a Compton-scatter energy window for scatter correction (SC-OSEM). For each radionuclide the authors separately acquired high-count projections of radioactivity in the myocardium wall, liver, and soft tissue background compartments of a water-filled torso phantom, and they generated synthetic projections of various dual-radionuclide activity distributions. Images of different combinations of myocardium wall/background activity concentration ratios for each radionuclide were reconstructed by NSC-OSEM, SC-OSEM, and MC-JOSEM. For activity estimation in the myocardium wall, MC-JOSEM always produced the best relative bias and relative standard deviation compared with NSC-OSEM and SC-OSEM for all the activity combinations. On average, the relative biases after 100 iterations were 8.1% for 99mTc and 3.7% for 123I with MC-JOSEM, 39.4% for 99mTc and 23.7% for 123I with NSC-OSEM, and 20.9% for 99mTc with SC-OSEM. The relative standard deviations after 30 iterations were 0.7% for 99mTc and 1.0% for 123I with MC-JOSEM, as compared to 1.1% for 99mTc and 1.2% for 123I with NSC-OSEM and 1.3% for 99mTc with SC-OSEM. Finally, the authors compared the relative standard deviation after 30 iterations with the minimum theoretical variance on activity estimation, the Cramer-Rao lower bound (CRB), and with the biased CRB. The measured precision was larger than the biased bound values by factors of 2-4, suggesting that further improvement could be made to the method. PMID:19292000

  8. Thermodynamics of technetium related to nuclear waste disposal: Solubilities of Tc(IV) oxides and the electrode potential of the Tc(VII)/Tc(IV)--oxide couple

    SciTech Connect

    Meyer, R E; Arnold, W D; Case, F I; O'Kelley, G D

    1989-06-01

    Solubilities of Tc(IV) oxides have been determined in a number of solutions in the pH range 1 to 10. Technetium oxide was prepared by precipitation upon purified sand with a 30% excess of hydrazine and by electrodeposition. The oxide-covered sand was transferred to a small column, and the solutions to be studied were continuously cycled through the column. The electrodeposited oxide was formed on a platinum mesh electrode, and after careful rinsing, the solution to be studied was added to the electrolytic cell. The concentrations of total technetium and Tc(IV) species in the solutions were periodically determined by separating the oxidized and reduced technetium species using a solvent extraction procedure and counting the beta activity of the /sup 99/Tc with a liquid scintillation counter. In basic solutions, the concentrations of Tc(IV) species in equilibrium with the oxide were in the range of 10/sup /minus/8/ to 10/sup /minus/9/ mol/L and tended to increase slightly with pH. In acid solutions the concentrations were much higher and were consistent with literature data on the hydrolytic species of Tc(IV). Solubilities appeared to reach a minimum in the intermediate pH range, and they were generally a factor of three or four lower for oxides electrodeposited in basic solutions compared to those for oxides electrodeposited from acid solution. The oxides were hydrated, and assuming a formula of TcO/sub 2//center dot/nH/sub 2/O, the value of n was found to be 1.63 +- 0.28. These data can be used to estimate Tc(IV) solubilities for cases where solubility limits transport of technetium in reducing environments of high-level waste repositories. 22 refs., 7 figs., 9 tabs.

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

    NASA Astrophysics Data System (ADS)

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

    2011-06-01

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

  10. 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.

  11. 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.

  12. Development and applications of high Tc superconducting bulk materials

    Microsoft Academic Search

    Z. Z. Hu; J. X. Jin; J. Liu; H. T. Ren; L. H. Lei; T. F. Xiang

    2009-01-01

    This paper summarizes the high Tc superconducting (HTS) bulk materials, with regard to material preparations, characteristics, and practical applications. Consequently it provides the technical base for practical development and applications of the HTS bulk materials to devices.

  13. Some inverse problems in the studies of high {Tc} superconductivity

    SciTech Connect

    Xi, D.X.; Tao, W.; GuiCun, M.; Dai, J.X.

    1999-12-20

    Two topics are reviewed or studied in this paper: (1) the specific heat-phonon spectrum inversion problem; and (2) the inverse relaxation problem in high {Tc} superconductors and finding its maximum current density problem.

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

    NASA Astrophysics Data System (ADS)

    Riofrio, L. M.

    2011-03-01

    The Lunar Laser Ranging Experiment reports the Moon receding at an anomalous rate. Independent experiments show a lower rate. A cosmology where GM=tc^3 may explain the anomaly. As with Mercury, orbital discrepancies may have great implications.

  15. 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.

  16. 99m Tc labeling of the scorpion ( Tityus serrulatus ) antivenom

    Microsoft Academic Search

    D. S. Cardoso; R. J. Rodrigues; V. P. C. P. Toledo; T. Moraes-Santos; V. N. Cardoso; E. A. Nunan

    2008-01-01

    F(ab’)2 is the fragment involved in the immunotherapy for scorpion stings and it would be convenient to label it with 99mTc for organ distribution and pharmacokinetics studies. The aim of the present study was to label scorpion antivenom F(ab’)2 with 99mTc keeping its biological activity, integrity and stability. High labeling yield was obtained using stannous chloride and\\u000a sodium borohydride. Stability,

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

    Microsoft Academic Search

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

    1985-01-01

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

  18. 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.

  19. The Rise of Tc: A Promising Paradigm via Interfacial Mechanism

    NASA Astrophysics Data System (ADS)

    Chu, C. W.; Lv, B.; Deng, L. Z.; Lorenz, B.; Jawdat, B.; Gooch, M.; Shrestha, K.; Zhao, K.; Zhu, X. Y.; Xue, Y. Y.; Wei, F. Y.

    2013-07-01

    Following the seminal detection of superconductivity at 35 K in the first cuprate high temperature superconductor Ba-doped ternary LCO (La214) by Mueller and Bednorz in 1986, the discovery of the first liquid nitrogen superconductor quaternary YBCO (Y123) with a transition temperature Tc of 93 K by Chu, Wu, and colleagues in 1987 has ushered in the modern era of high temperature superconductivity (HTS). In the ensuing 25 years, great progress has been made in all areas of HTS research and development, from materials to physics to devices. However, the Tc remains at 134 K in quaternary HBCCO (Hg1223) at ambient pressure achieved in 1993 by Schilling et al. and at 164 K in the same compound under high pressure in the same year by Gao et al. A holistic multidisciplinary enlightened empirical approach has been proposed to search for superconductors with higher Tc, which includes the discovery of new compounds empirically and the realization of novel mechanisms proposed by theorists. Recently, we have observed nonbulk superconductivity in single crystalline rare-earth doped Ca122 samples with an onset Tc of 49 K, higher than the Tc of any known compounds formed of the constituent elements at ambient or under high pressures. Subsequent systematic structural, electrical, magnetic, and calorimetric investigations suggest that the observation may be attributed to an interface-induced Tc, thus suggesting a possible new paradigm for higher Tc. In this presentation, our results will be presented and discussed, following a brief recollection of a few events in our lab in the continuing search for higher Tc, even though a number of review articles have appeared.

  20. The Amity Prison TC EvaluationReincarceration Outcomes

    Microsoft Academic Search

    HARRY K. WEXLER; GEORGE De LEON; GEORGE THOMAS; DAVID KRESSEL; JEAN PETERS

    1999-01-01

    This article is drawn from an ongoing evaluation of the effectiveness of the Amity prison therapeutic community (TC) and aftercare program for substance abusers located in San Diego, California. Data collection consisted of face-to-face interviews and reviews of criminal justice records on a sample of 715 male inmates. Subjects were randomly assigned to the prison TC intent-to-treat group and no-treatment

  1. Immunization with mutant HPV16 E7 protein inhibits the growth of TC-1 cells in tumor-bearing mice

    PubMed Central

    LI, YAN-LI; MA, ZHONG-LIANG; ZHAO, YUE; ZHANG, JING

    2015-01-01

    Two human papillomavirus (HPV) 16 oncogenic proteins, E6 and E7, are co-expressed in the majority of HPV16-induced cervical cancer cells. Thus, the E6 and E7 proteins are good targets for developing therapeutic vaccines for cervical cancer. In the present study, immunization with the mutant non-transforming HPV16 E7 (mE7) protein was demonstrated to inhibit the growth of TC-1 cells in the TC-1 mouse model. The HPV16 mE7 gene was amplified by splicing overlap extension polymerase chain reaction using pET-28a(+)-E7 as a template, and the gene was cloned into pET-28a(+) to form pET-28a(+)-mE7. Compared with the E7 protein, mE7 lacks amino acid residues 94–98, and at residue 24, there is a Cys to Gly substitution. pET-28a(+)-mE7 was then introduced into Escherichia coli Rosetta. The expression of mE7 was induced by isopropyl ?-D-1-thiogalactopyranoside. The mE7 protein was purified using Ni-NTA agarose and detected by SDS-PAGE and western blot analysis. In the tumor prevention model, no tumor was detected in the mice vaccinated with the mE7 protein. After 40 days, the tumor-free mice and control mice were challenged with 2×105 TC-1 cells. All control mice developed tumors six days later, but mE7 immunized mice were tumor free until 90 days. In the tumor therapy model, the TC-1 cells were initially injected subcutaneously, and the mice were subsequently vaccinated. Vaccination against the mE7 protein may significantly inhibit TC-1 cell growth compared to the control. These results demonstrated that immunization with the HPV16 mE7 protein elicited a long-term protective immunity against TC-1 tumor growth and generated a significant inhibition of TC-1 growth in a TC-1 mouse model.

  2. (47171) 1999 TC 36, A transneptunian triple

    NASA Astrophysics Data System (ADS)

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

    2010-06-01

    We present new analysis of HST images of (47171) 1999 TC 36 that confirm it as a triple system. Fits to the point-spread function (PSF) 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 7 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 M sys = 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 d=286-38+45km,d=265-35+41kmandd=139-18+22km. The relative sizes of these components are more similar than in any other known multiple in the Solar System. Taken together, the diameters and system mass yield a bulk density of ?=542-211+317kgm. HST photometry shows that component B is variable with an amplitude of ?0.17 ± 0.05 magnitudes. Components A1 and A2 do not show variability larger than 0.08 ± 0.03 magnitudes approximately consistent with the orientation of the mutual orbit plane and tidally distorted equilibrium shapes. The system has high specific angular momentum of J/ J' = 0.93, comparable to most of the known transneptunian binaries.

  3. Clinical comparison of diisopropyl-IDA Tc 99m and diethyl-IDA Tc 99m for evaluation of the hepatobiliary system

    SciTech Connect

    Klingensmith, W.C. III; Fritzberg, A.R.; Spitzer, V.M.; Kuni, C.C.; Shanahan, W.S.M.

    1981-09-01

    Thirty-one patients with a wide range of hepatobiliary function and clinical diagnoses were studied with both diisopropyl-IDA Tc 99m and diethyl-IDA Tc 99m. Images were similar except for an increased liver-to-kidney ratio with diisopropyl-IDA Tc 99m and a tendency toward an increased liver-to-background ratio at five minutes with diisopropyl-IDA Tc 99m. Quantification of the relative hepatocyte extraction efficiency indicated a 16% higher extraction efficiency for diisopropyl-IDA Tc 99m. Both radiopharmaceuticals demonstrated increasing renal excretion with increasing total serum bilirubin levels; however, renal excretion of diisopropyl-IDA Tc 99m increased more slowly than excretion of diethyl-IDA Tc 99m. We conclude that, while the overall differences between these two radiopharmaceuticals are small, diisopropyl-IDA Tc 99m is superior because of a lower renal excretion rate in patients with decreased hepatocyte function.

  4. Usage of radiopharmaceuticals in the development of pharmaceutical drug delivery systems: validation of [ 99mTc]DTPA and [ 99mTc]ECD

    Microsoft Academic Search

    Mariella Terán; Eduardo Savio; Andrea Paolino; Malcolm Frier

    2004-01-01

    Tablets containing drugs of different lipophilicity, ranitidine and cinarizine, and placebo were prepared and their in vitro behaviour was studied by dissolution and disintegration tests. [99mTc]Diethylenetriamine-pentaacetic acid ([99mTc]DTPA) and [99mTc]ethyl cysteinate dimer ([99mTc]ECD) were used as tracers of the process. Both of them were added to tablets during wet granulation. Dissolution and disintegration profiles were assessed at different pH values

  5. 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.

  6. TcA, the putative transposase of the C. elegans Tc1 transposon, has an N-terminal DNA binding domain.

    PubMed Central

    Schukkink, R F; Plasterk, R H

    1990-01-01

    Tc1 is a transposon present in several copies in the genome of all natural isolates of the nematode C.elegans; it is actively transposing in many strains. In those strains Tc1 insertion is the main cause of spontaneous mutations. The transposon contains one large ORF that we call TcA; we assume that the TcA protein is the transposase of Tc1. We expressed TcA in E.coli, purified the protein and showed that it has a strong affinity for DNA (both single stranded and double stranded). A fusion protein of beta-galactosidase and TcA also exhibits DNA binding; deletion derivatives of this fusion protein were tested for DNA binding. A deletion of 39 amino acids at the N-terminal region of TcA abolishes the DNA binding, whereas a deletion of 108 C-terminal amino acids does not affect DNA binding. This shows that the DNA binding domain of TcA is near the N-terminal region. The DNA binding capacity of TcA supports the assumption that TcA is a transposase of Tc1. Images PMID:2156234

  7. 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…

  8. Graphical analysis of 99mTc thyroid scintigraphy.

    PubMed

    Okada, Junichi; Higashitsuji, Yoshimasa; Tamada, Hajime; Kawashiro, Osamu; Fukuzaki, Tsuyoshi; Suzuki, Tatsuhiko; Itou, Hisao

    2003-05-01

    A new non-invasive simple method for quantitative evaluation of thyroid was presented using graphical analysis of the transfer process of technetium-99m pertechnetate (99mTc) from the blood to thyroid. Thirty subjects were studied. After a bolus injection of 111 MBq of 99mTc, the data were recorded on a 128 x 128 matrix as 60 frames of 1.5-second duration. ROIs were placed over the aortic arch and bilateral thyroid lobes. The activity of the aorta was monitored instead of the arterial activity. Graphical analysis by plotting B(t)/A(t) versus integral(0)t A(tau)d tau/A(t) gave a straight line within the first 30 seconds in all subjects. The slope of the line was the unidirectional influx rate of 99mTc (k(u)). Thyroid perfusion index (TPI) was calculated to standardize where the ratio of ROI(thyroid) size to ROI(aorta) size was set as 10. K(u) and TPI showed good correlation with 99mTc thyroid uptake. Hyperthyroid patients showed high values of k(u) and TPI. Considering that these indices were determined at the first pass of 99mTc, this method may be helpful especially in the evaluation of thyroid perfusion. PMID:12846546

  9. 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.

  10. Radiolabelling of human platelets with 99mTc-HMPAO.

    PubMed

    Vorne, M; Honkanen, T; Karppinen, K; Röning, M; Sakki, S

    1989-05-01

    The optimum conditions for labelling platelets with lipophilic 99mTc-hexamethyl propylene amine oxime (99mTc-HMPAO) were evaluated. An aseptic closed system was used throughout the procedure in patient studies. 48 ml blood were withdrawn into 12 ml ACD using sterile 60 ml plastic syringes. After mixing, the blood was transferred to sterile 10 ml vacuum tubes and platelets were isolated according to standard centrifugation procedures. The labelling efficiency was not dependent upon incubation temperature (22 degrees C, 37 degrees C) but was greater in saline than in the presence of plasma. The labelling efficiency increased with time up to 60 min in saline. The elution of 99mTc from platelets was about 25% in plasma milieu in vitro but did not increase with time during 160 min. 5 patients with verified fresh deep vein thrombosis in the lower leg were imaged after injection of labelled autologous platelets. All 4 of the patients without anticoagulant therapy showed positive uptake of 99mTc-HMPAO-labelled platelets, but the 5th patient--under heparin therapy--was negative in scintigraphy. Our results are encouraging and 99mTc-HMPAO-labelled platelets offer a promising tool for evaluating various clinical situations. PMID:2731595

  11. 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.

  12. 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

  13. 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

  14. Imaging experimental intraabdominal abscesses with 99mTc-PEG liposomes and 99mTc-HYNIC IgG.

    PubMed Central

    Dams, E T; Reijnen, M M; Oyen, W J; Boerman, O C; Laverman, P; Storm, G; van der Meer, J W; Corstens, F H; van Goor, H

    1999-01-01

    OBJECTIVE: To evaluate the accuracy of technetium-99m-labeled polyethylene glycol-coated liposomes (99mTc-PEG liposomes) and technetium-99m-labeled nonspecific human immunoglobulin G (99mTc-HYNIC IgG) for the scintigraphic detection of experimental intraabdominal abscesses in comparison with that of a standard agent, gallium-67 citrate. BACKGROUND: Scintigraphic imaging techniques can be very useful for the rapid and accurate localization of intraabdominal abscesses. Two newly developed radiolabeled agents, 99mTc-PEG liposomes and 99mTc-HYNIC IgG, have shown to be excellent agents for imaging experimental focal infection, but have not yet been studied in the detection of abdominal abscesses. METHODS: Intraabdominal abscesses were induced in 42 rats using the cecal ligation and puncture technique. Seven days later, randomized groups of rats received 99mTc-PEG liposomes, 99mTc-HYNIC IgG, or 67Ga citrate intravenously. The rats were imaged up to 24 hours after the injection. The biodistribution of the radiolabel was determined by counting dissected tissues ex vivo. Macroscopic intraabdominal abnormalities and focal uptake on the images were independently scored on a semiquantitative scale. RESULTS: 99mTc-PEG liposomes provided the earliest scintigraphic visualization of the abscess (as soon as 2 hours after the injection vs. 4 hours for the other two agents). Liposomes, IgG, and gallium all showed similarly high absolute uptake in the abscess. Focal uptake of liposomes and gallium correlated best with the extent of the macroscopic abnormalities. CONCLUSIONS: 99mTc-PEG liposomes and 99mTc-HYNIC IgG performed at least as well as the standard agent, 67Ga citrate, in the detection of experimental intraabdominal abscesses, with obvious advantages such as lower radiation exposure and more favorable physical properties. Of the two technetium agents, the liposomes seemed to be superior, providing the earliest diagnostic image and the best correlation with the inflammatory abnormalities. In addition, the preferential localization of radiolabeled PEG liposomes holds promise for targeted delivery of liposome-encapsulated drugs. Images Figure 1. PMID:10203089

  15. Flux-flow behavior in high Tc superconductors

    NASA Astrophysics Data System (ADS)

    Raissi, F.; Hassani, F.

    2014-06-01

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

  16. Superfluid amplitude fluctuations above Tc in a unitary Fermi gas

    NASA Astrophysics Data System (ADS)

    Li, Hua; Jackiewicz, Jason; Bedell, Kevin S.

    2015-02-01

    We study the transport properties of a Fermi gas with strong attractive interactions close to the unitary limit. In particular, we compute the spin diffusion lifetime of the Fermi gas due to superfluid fluctuations above the BCS transition temperature Tc. To calculate the spin diffusion lifetime we need the scattering amplitudes. The scattering amplitudes are dominated by the superfluid fluctuations at temperatures just above Tc. The normal scattering amplitudes are calculated from the Landau parameters. These Landau parameters are obtained from the local version of the induced interaction model for computing Landau parameters. We also calculate the leading order finite temperature correction to the diffusion lifetime. A calculation of the spin diffusion coefficient is presented in the end. Upon choosing a proper value of F0a, we are able to present a good match between the theoretical result and the experimental measurement, which indicates the presence of the superfluid fluctuations near Tc.

  17. Tc-99m pentavalent DMSA scintigraphy in myelofibrosis detection.

    PubMed

    Koutsikos, John T; Velidaki, Antigone; Athanasoulis, Theodoros

    2006-12-01

    In a 62-year-old man with medullary carcinoma of the thyroid, a postoperative Tc-99m dimercaptosuccinic acid [(V) DMSA] study was requested. In the Tc-99m (V) DMSA scan. no abnormalities, indicating local recurrence or metastatic disease, were observed. However, there was increased uptake in the spleen and liver and significantly diffusely increased uptake in the bone marrow. The patient also had a history of myelofibrosis and these findings appear to have been the result of this pathology. PMID:17117079

  18. 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.

  19. 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.

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

    PubMed

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

    1995-01-01

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

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

    PubMed Central

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

    2014-01-01

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

  2. [The effect of contaminants on characteristics of 99mTC radiopharmaceuticals].

    PubMed

    Vucina, J; Vuga, D; Maksin, T; Vanli?-Razumeni?, N

    1994-01-01

    The influence of 99Tc, oxygen and cupric ions on labeling yield of eight radiopharmaceuticals was examined. The results obtained for commercial and experimental preparations were compared. The latter were formulated so that the content of 99Tc was 4 times, hydrogen peroxide 5 times and copper 50 times higher than in commercial preparations. It was found that these impurities did not affect labeling of 99mTc(Sn)tetracyclin, 99mTc(Sn)dimercaptosuccinate and 99mTc(Sn)diethylida. Long-living 99Tc did not affect any preparations. Oxygen influenced in lesser extent 99mTc(Sn) DTPA, 99mTc(Sn)pyrophosphate and 99Tc(Sn) dicarboxy-propane diphosphonate but strongly 99mTc(Sn) phytate 99mTc(Sn)methylene diphosphonate. Copper influenced only 99mTc(Sn)-methylene diphosphonate. Therefore this preparation was examined in broader range of copper concentrations. According to the results of radiochemical and biodistribution analyses it was concluded that under the experimental conditions the effect of oxygen and copper resulted in an increased content of free 99mTc-pertechnetate in the examined preparations. PMID:7565319

  3. Poor Tc-99m dimercaptosuccinic acid uptake, re-evaluation with Tc-99m MAG3 scintigraphy in Lowe syndrome

    PubMed Central

    Koca, Gokhan; Atilgan, Hasan Ikbal; Demirel, Koray; Diri, Akif; Korkmaz, Meliha

    2011-01-01

    Tc-99m dimercaptosuccinic acid (DMSA) is filtered through the glomeruli and reabsorbed by the proximal tubules as low molecular weight proteins. In Lowe syndrome this mechanism is impaired and so poor DMSA uptake is seen. Poor DMSA uptake was shown in very few studies, but none mentioned normal Tc-99m MAG3 uptake. In this case, the patient had poor DMSA uptake, normal MAG3 uptake and a neurogenic bladder in anterior to the left kidney that attenuates left kidney. PMID:23559713

  4. RETRIEVALS OF CLOUD OPTICAL DEPTH AND EFFECTIVE RADIUS FROM A THIN-CLOUD ROTATING SHADOWBAND RADIOMETER (TC-RSR)

    E-print Network

    RADIOMETER (TC-RSR) Bangsheng Yin, ASRC, State University of New York Qilong Min, State University of New-rotating shadowband radiometer (TC-RSR) was developed and deployed in a field campaign at the ARM SGP site. The TC

  5. Micromechanical Circuits for Wireless Communications Clark T.-C. Nguyen

    E-print Network

    Nguyen, Clark T.-C.

    Micromechanical Circuits for Wireless Communications Clark T.-C. Nguyen Center for Integrated, Michigan 48109-2122 email: ctnguyen@eecs.umich.edu Abstract Micromechanical communication circuits fab transceiver front- end architecture is then presented that uses these micromechanical circuits in large quanti

  6. High- Tc superconductors: Fabricating technologies and future perspectives

    SciTech Connect

    Goretta, K.C.; Wu, W.; Wu, C.T.; Xu, D.; Youngdahl, C.A.; Shi, Donglu; Singh, J.P.; Picciolo, J.J.; Lanagan, M.T.; Hull, J.R.; Dusek, J.T.; Dorris, S.E.; Chen, Nan; Biondo, A.C.; Balachandran, U.; Poeppel, R.B.

    1991-05-01

    Processing methods for production of bulk high-{Tc} superconductors are reviewed. Conductors made by conventional forming and sintering methods can generally carry only small current densities. Melting and powder-in-tube methods yield superior conductors, but further improvements are necessary before these superconductors can be employed in most large-scale applications. 36 refs., 6 figs.

  7. Superconducting fluctuations and pseudogap in high-Tc cuprates

    NASA Astrophysics Data System (ADS)

    Rullier-Albenque, F.; Alloul, H.

    2012-03-01

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

  8. Fault current characteristics in a technical high Tc superconductor

    Microsoft Academic Search

    K. Ryu; S. W. Kim; B. J. Choi; S. D. Hwang

    2004-01-01

    A Bi-2223 tape has been developed for low-field power applications such as power cables or transformers working at liquid nitrogen temperature. For such applications it is required to understand fault current characteristics of the technical high temperature (Tc) superconductor. In this paper, we prepared two types of the samples with similar insulation structures to power cables and transformers: the straight

  9. Tc TUNING OF TUNGSTEN TRANSITION EDGE SENSORS USING IRON IMPLANTATION

    E-print Network

    California at Berkeley, University of

    Tc TUNING OF TUNGSTEN TRANSITION EDGE SENSORS USING IRON IMPLANTATION B.A.Younga*, T. Saabb, B developed a technique for precisely tuning the transition temperature of superconducting tungsten (W) films superconductor, tungsten. Our motivation for this work was a desire to develop a reliable technique for optimally

  10. 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.

  11. 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

  12. 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 ...

  13. Clinical comparison of /sup 99m/Tc-diethyl-IDA and /sup 99m/Tc-PIPIDA for evaluation of the hepatobiliary system

    SciTech Connect

    Klingensmith, W.C.; Fritzberg, A.R.; Spitzer, V.M.; Koep, L.J.

    1980-01-01

    Fifteen patients with a wide range of hepatobiliary function were studied with both /sup 99m/Tc-diethyl-IDA and /sup 99m/Tc-PIPIDA. In images obtained 5 to 60 minutes after injection, /sup 99m/Tc-diethyl-IDA was clearly superior with respect to liver/background, hepatic ducts/liver, and small bowel/background ratios. The /sup 99m/Tc-diethyl-IDA transit time from blood to small intestine averaged 12.2 minutes less than that of /sup 99m/Tc-PIPIDA. Quantification of relative hepatocyte extraction efficiency indicated that it was 2.15 times higher for /sup 99m/Tc-diethyl-IDA. Cumulative 3-hour urine collections following injection demonstrated increasing renal excretion of /sup 99m/Tc-PIPIDA with rising total serum bilirubin levels in a manner quantitatively similar to that determined previously for /sup 99m/Tc-diethyl-IDA. The authors conclude that /sup 99m/Tc-diethyl-IDA is superior to /sup 99m/Tc-PIPIDA for studies of the hepatobiliary system.

  14. 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.

  15. Two routes for 99m Tc-DMSA uptake into the renal cortical tubular cell

    Microsoft Academic Search

    A. M. Peters; D. H. Jones; K. Evans; I. Gordon

    1988-01-01

    Critical factors determining the renal handling of 99mTc-dimercaptosuccinic acid (DMSA) are protein binding in plasma and the renal 99mTc-DMSA extraction efficiency. Comparison of the count rate over soft tissue with that over the cardiac blood pool about 1 h after injection demonstrated that 99mTc-DMSA is not exclusively an intravascular label. 99mTc-DMSA was 76% protein bound in plasma as demonstrated by

  16. 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.

  17. Is AZT\\/3TC therapy effective against FIV infection or immunopathogenesis?

    Microsoft Academic Search

    Maki Arai; Donald D Earl; Janet K Yamamoto

    2002-01-01

    In vitro and in vivo prophylactic and therapeutic efficacy of AZT\\/3TC treatment was evaluated against feline immunodeficiency virus (FIV) infection. In vitro studies utilized FIV-infected peripheral blood mononuclear cells (PBMCs) or FIV-infected T-cell lines treated with AZT (azidothymidine) alone, 3TC alone, or AZT\\/3TC combination and tested for anti-FIV activity and drug toxicity. AZT\\/3TC combination had additive to synergistic anti-FIV activities

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

    PubMed Central

    Lembrechts, Johan F.; Desmet, Gilbert M.

    1986-01-01

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

  19. Binding of ciprofloxacin labelled with technetium Tc 99m versus 99mTc-pertechnetate to a live and killed equine isolate of Escherichia coil.

    PubMed

    Alexander, Kate; Drost, W Tod; Mattoon, John S; Kowalski, Joseph J; Funk, Julie A; Crabtree, Amanda C

    2005-10-01

    This paper describes a simple methodology for evaluating the bacterial binding of ciprofloxacin labelled with technetium Tc 99m. Using this methodology, the binding of 99mTc-ciprofloxacin by live Escherichia coli was compared with the binding of 99mTc-ciprofloxacin by killed E. coli and the binding of 99mTc-pertechnetate (99mTcO4-) by live E. coli. The antimicrobial effect of 99mTc-ciprofloxacin on E. coli was evaluated. Four groups were defined: live E. coli with 99mTc-ciprofloxacin, live E. coli with 99mTcO4 , killed E. coli with 99mTc-ciprofloxacin, and killed E. coli with 99mTcO4-. After 0, 2, and 4 h of incubation of 1 x 10(8) colony-forming units of E. coli suspended in 5 mL of sterile distilled water with 1.85 MBq of 99mTc-ciprofloxacin or 99mTcO4, 1 mL from each sample was centrifuged. The radioactivity of the bacterial pellet and that of the supernatant were measured separately, and the percentage of sample radioactivity attributable to bacterial binding was calculated. Of the 99mTc-ciprofloxacin, 3.6% to 5.9% was bound to live or killed E. coli; only 0.1% to 0.2% of the 99mTcO4- was bound to live E. coli (P < 0.0001). No significant difference in 99mTc-ciprofloxacin binding was found between live and killed E. coli (P = 0.887). An antimicrobial effect on E. coli was seen with 99mTc-ciprofloxacin: colony counts were reduced after 4 h. The small amount of 99mTc-ciprofloxacin binding and the lack of difference in binding between live and killed E. coli may limit the utility of this methodology in evaluating the presence of E. coli infection. PMID:16479725

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

    E-print Network

    Ertaull, Levent

    RSA and Elliptic Curve- ElGamal Threshold Cryptography (ECCEG-TC) Implementations for Secure Data based TC and Elliptic curve cryptography TC using ElGamal algorithms. We make a case why RSA will be more appropriate for these networks. II. RSA VS ELLIPTIC CURVE CRYPTOLOGY RSA has been successfully

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

    E-print Network

    Lu, Jianguo

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

  2. First pass cerebral extraction studies with Tc-99m propylene amine oxime complexes

    SciTech Connect

    Hoffman, T.J.; Seger, R.M.; McKenzie, E.H.; Volkert, W.A.; Holmes, R.A.

    1985-05-01

    Tc-99m propylene amine oxime (Tc-99m-PnAO) is a stable chelate that passively crosses into the crebral cortex. A series of Tc-99m propylene amine oxime derivatives were prepared and studied to determine the effect of lipophilicity on cerebral uptake and retention in rabbit brain.

  3. Statistical parametric mapping demonstrates asymmetric uptake with Tc-99m ECD and Tc-99m HMPAO SPECT in normal brain

    PubMed Central

    Brinkmann, Benjamin H; Jones, David T; Stead, Matt; Kazemi, Noojan; O'Brien, Terence J; So, Elson L; Blumenfeld, Hal; Mullan, Brian P; Worrell, Gregory A

    2012-01-01

    Tc-99m ethyl cysteinate diethylester (ECD) and Tc-99m hexamethyl propylene amine oxime (HMPAO) are commonly used for single-photon emission computed tomography (SPECT) studies of a variety of neurologic disorders. Although these tracers have been very helpful in diagnosing and guiding treatment of neurologic disease, data describing the distribution and laterality of these tracers in normal resting brain are limited. Advances in quantitative functional imaging have demonstrated the value of using resting studies from control populations as a baseline to account for physiologic fluctuations in cerebral perfusion. Here, we report results from 30 resting Tc-99m ECD SPECT scans and 14 resting Tc-99m HMPAO scans of normal volunteers with no history of neurologic disease. Scans were analyzed with regions of interest and with statistical parametric mapping, with comparisons performed laterally (left vs. right), as well as for age, gender, and handedness. The results show regions of significant asymmetry in the normal controls affecting widespread areas in the cerebral hemispheres, but most marked in superior parietotemporal region and frontal lobes. The results have important implications for the use of normal control SPECT images in the evaluation of patients with neurologic disease. PMID:21934696

  4. The Efficacy of Tc99m Dimercaptosuccinic Acid (Tc-DMSA) Scintigraphy and Ultrasonography in Detecting Renal Scars in Children with Primary Vesicoureteral Reflux (VUR)

    Microsoft Academic Search

    Y Temiz; T Tarcan; F F Önol; H Alpay; F ?im?ek

    2006-01-01

    Introduction: Pyelonephritis-induced renal scarring in children is a major predisposing factor for proteinuria, hypertension, and ultimate\\u000a renal failure. The aim of this study was to investigate and compare the efficacy of Tc99m dimercaptosuccinic acid (Tc-DMSA)\\u000a renal scintigraphy and renal ultrasonography (USG) in detecting renal scars in children with primary vesicoureteral reflux\\u000a (VUR). Materials and methods: Tc-DMSA scan and USG studies

  5. C15-C18 isomers synthesized from ( TC)-2,3,7,8-tetrachlorodibenzofuran via surface chlorination

    SciTech Connect

    Peterson, R.G.

    1987-03-01

    At present, the identification and quantitation of polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) is performed with GC/MS/DS systems and is facilitated by using relative retention times and relative response factors based on ( TC)-isotopically labelled 2,3,7,8-TCDD, 2,3,7,8- TCDF, and OCDD. These compounds are used as internal standards for the analysis for TCDD, TCDF, and OCDD respectively and as surrogates for the analysis for penta, hexa, hepta chlorinated dibenzo-p-dioxin and dibenzofuran isomers and octachlorodibenzofuran. The use of isotopically labelled internal standards for all chlorination levels of dibenzo-p-dioxin and dibenzofuran would greatly improve the quality of currently generated analytical data from the analysis of various matrices for tetrachloro-through octachlorodibenzo-p-dioxins and dibenzofurans. However, these compounds are difficult to obtain commercially and are quite expensive to be adding to every sample prior to extraction. To circumvent these drawbacks in the scheme of analysis for PCDFs, the polychlorination of ( TC)-2,3,7,8-TCDF was attempted and accomplished using a method based on previously published work that started with ( TC)-2,3,7,8-TCDD. After synthesis and quantitation of the labelled products, they can be added to a matrix before extraction and work up and used as true internal standards as opposed to surrogates.

  6. Can Tc 99m DTPA be Used in Adult Patients in Evaluation of Relative Renal Function Measurement as the Reference Tc 99m DMSA Method?

    PubMed Central

    Yalç?n, Hülya; Özen, Aynur; Günay, Emel Ceylan; Özaslan, ?nci Aliç; Özer, Cahit

    2011-01-01

    Objective: In the literature, there are many reports comparing relative renal function calculated with Tc 99m DTPA and Tc 99m DMSA in adults and children. However, there is no consensus about the results. As there is indeterminacy in the reliability of Tc 99m DTPA for the calculation of the relative renal functions, we retrospectively designed a study to compare the relative renal functions measured with Tc 99m DMSA and Tc 99m DTPA in adult patients with renal diseases Material and Methods: We retrospectively analyzed the data of 144 patients who applied to Nuclear Medicine Department of three hospitals between 2009 and 2010 and who had both dynamic and static renal imaging. Renal dynamic scintigraphies were compared to the relative function measured using Tc 99m DMSA static scintigraphy. Comparison of relative renal function measurements using dynamic and static renal scintigraphies was performed using Pearson correlation test. The comparison results were expressed with Bland-Altman analysis. Results: The study was conducted with 144 patients and 288 kidneys. Fifty six of patients were male. Mean age was 39.9±15.2 years. Thirty four patients had hydronephrosis, 28 pyelonephritis, 53 renal calculi, 3 chronic renal failure, 2 acute renal failure, 1 benign renal neoplasia, 15 renal atrophy, 8 ureteropelvic junction stenosis. Relative renal function was calculated in Tc 99m DMSA and 99m Tc-DTPA studies. The mean relative renal functions measured with Tc 99m DTPA was 52.54±23.09% and 47.25±23.09, with Tc 99m DMSA 52.85±21.80% and 47.07±21.77% for right and left kidneys, respectively. In bivariate correlation analysis (Pearson) a significant positive correlation was found between the relative renal functions calculated with Tc 99m DTPA and Tc 99m DMSA (r =0.937, p< 0.001). In Bland-Altman plots, the mean difference between two methods was 0.3 and the correlation limits were between 16.2 to -15.5. Conclusion: As a result, we concluded that Tc 99m DTPA is also a good method for the relative renal function evaluation when compared to Tc 99m DMSA scan. Although Tc 99m DMSA is the most reliable method for the calculation of relative renal function, Tc 99m DTPA can be another choice for the calculation of relative renal function without a complementary DMSA scan particularly in patients who require renogram curve and GFR calculations. Conflict of interest:None declared. PMID:23486843

  7. 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.

  8. High-Tc/high-coupling relaxed PZT-based single crystal thin films

    NASA Astrophysics Data System (ADS)

    Wasa, K.; Matsushima, T.; Adachi, H.; Matsunaga, T.; Yanagitani, T.; Yamamoto, T.

    2015-03-01

    Pb(Zr,Ti)O3 (PZT)-based ferroelectric ceramics exhibit high piezoelectricity, however, their Curie temperature (Tc) values are not so high, i.e., Tc < 400 °C. PZT-based piezoelectric thin films with higher Tc would be beneficial for improved micro actuators, sensors, memories, and piezoelectric micro-electro mechanical systems. In-plane biaxial strained PZT thin films in a laminated composite structure are known to exhibit enhanced Tc; however, the thickness of PZT-based thin films is limited to below a critical thickness typically <50 nm. The Tc of relaxed PZT-based thin films with thicknesses greater than the critical thickness is the same as bulk Tc. However, a sort of relaxed PZT-based single-crystal thin films exhibit extraordinary high Tc, Tc = ˜600 °C. In addition, the films show extremely low dielectric constant, ?/?o ˜ 100 with high coupling factor, kt ˜ 0.7, and large remnant polarization, Pr ˜ 100 ?C/cm2. These exotic properties would result from the single-domain/single-crystal structure. The enhanced Tc is possibly caused by the highly stable interface between the PZT-based thin films and substrates. Their ferroelectric performances are beyond those of conventional PZT. The high-Tc/high-coupling performances are demonstrated, and the possible mechanisms of the high Tc behavior in relaxed PZT-based single-crystal thin films are discussed.

  9. Tc anisotropy and phase separation in strained Vanadium Dioxide films

    NASA Astrophysics Data System (ADS)

    Liu, Mengkun; Wagner, Martin; Abreu, Elsa; Kittiwatanakul, Salinporn; McLeod, Alexander; Goldflam, Michael; Fei, Zhe; Dai, Siyuan; Fogler, Michael; Lu, Jiwei; Wolf, Stuart; Averitt, Richard; Basov, D. N.

    2013-03-01

    We report Infrared near field study on strain induced transition temperature (Tc) anisotropy in vanadium dioxide (VO2) films via direct visualization of a spontaneous structural and electronic phase separation. The films are epitaxially grown on [110]R or [100]R TiO2 substrates and exhibit large uniaxial strain. By mapping the film topography with AFM and electronic percolation with Infrared scattering scanning near-field optical microscopy, a temperature dependent electron-lattice correlation can be clearly observed. Our work sheds a new light onto the nature of the Tc anomaly in metal-insulator transition and leads to the possibility of controlling the material's properties through strain induced phase separation.

  10. Thermal desorption of 3He from T@C 60

    NASA Astrophysics Data System (ADS)

    Sahoo, Rashmi R.; Patnaik, Archita

    2001-11-01

    The interaction of recoil tritium (T), with an initial kinetic energy of 2.7 MeV with C 60 molecules, is studied in a 6Li( n, ?) T activated homogenized compound matrix of Li 2CO 3 and C 60. Liquid scintillation spectrometry coupled with high pressure liquid chromatography (HPLC) revealed endohedral T insertion into the fullerene cage upon extraction of the fullerene species into the organic phase. Solid state temperature programmed desorption profiles of the activated compound target showed the desorption of 3He gas (as a ?- decay product from T) from the endohedral T@C 60 at 882 °C. The deconvoluted evolved gas analysis-mass spectral (EGA-MS) data provided a 25% probability of T@C 60 formation upon nuclear activation of the compound target. The non-isothermal kinetics of the tritium desorption, studied as a function of temperature, revealed the process to be diffusion controlled.

  11. 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.

  12. Identification of pseudospin partner bands in {sup 108}Tc

    SciTech Connect

    Xu, Q.; Wang, J. G.; Ding, H. B.; Gu, L.; Yeoh, E. Y. [Department of Physics, Tsinghua University, Beijing 100084 (China); Zhu, S. J. [Department of Physics, Tsinghua University, Beijing 100084 (China); Department of Physics, Vanderbilt University, Nashville, Tennessee 37235 (United States); Hamilton, J. H.; Ramayya, A. V.; Hwang, J. K.; Liu, S. H.; Li, K. [Department of Physics, Vanderbilt University, Nashville, Tennessee 37235 (United States); Qi, B.; Meng, J. [School of Physics, Peking University, Beijing 100871 (China); Peng, J. [Department of Physics, Beijing Normal University, Beijing 100875 (China); Luo, Y. X. [Department of Physics, Vanderbilt University, Nashville, Tennessee 37235 (United States); Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Rasmussen, J. O.; Lee, I. Y. [Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Ma, W. C. [Department of Physics, Mississippi State University, Mississippi State, Mississippi 39762 (United States)

    2008-12-15

    High-spin structures in the neutron-rich {sup 108}Tc nucleus have been reinvestigated by measuring the prompt {gamma}-rays from spontaneous fission of {sup 252}Cf. A previously known collective band has been extended up to higher spin states and a new side band has been identified. These doublet bands are proposed as pseudospin partner bands with configurations {pi}1/2{sup +}[431] x {nu}[312{approx}5/2{sup +},3/2{sup +}], which is a first identification in A{approx}100 region. The particle-rotor model (PRM) was applied to calculate levels and B(M1)/B(E2) ratios of the bands in {sup 108}Tc. The calculated results are in good agreement with the experimental values.

  13. Clinical evaluation of /sup 99m/Tc-DMSA renogram

    SciTech Connect

    Van Poppel, H.; Vereecken, R.; Vekemans, K.; Verduyn, H.; Mortelmans, L.; de Roo, M.

    1985-04-01

    Two hundred-two /sup 99m/Tc-DMSA renograms for urologic problems were evaluated. Some technical aspects of the examination and the value of the scintigraphic depth estimation are discussed. Pre- and postoperative uptake values in patients with renal surgery and sequential postoperative examinations are considered. The value of DMSA renograms in predicting recovery in obstructive uropathy and in deciding to opt for conservative therapy or nephrectomy is discussed.

  14. Grain boundary weak links in high- Tc superconductors

    SciTech Connect

    Shi, D.; Sengupta, S.; Goretta, K.C.; Salem-Sugui, S. Jr. (Argonne National Lab., IL (United States)); Smith, M.; Lwin, Y.N. (Western Illinois Univ., Macomb, IL (United States). Dept. of Physics)

    1992-04-01

    The transport critical current density (Jc) for high-{Tc} thin films, bicrystals, and bulk ceramics is shown to be determined by magnetic field penetration into the grain boundaries. The gross grain orientations may not in all cases be an important factor in determining this penetration. The parameter ({lambda}{sub G}/{lambda}{sub J}){sup 2} can characterize the strength of the grain boundary coupling, which depends mainly on the crystal coherence and connectivity at the boundary area.

  15. Grain boundary weak links in high-{Tc} superconductors

    SciTech Connect

    Shi, D.; Sengupta, S.; Goretta, K.C.; Salem-Sugui, S. Jr. [Argonne National Lab., IL (United States); Smith, M.; Lwin, Y.N. [Western Illinois Univ., Macomb, IL (United States). Dept. of Physics

    1992-04-01

    The transport critical current density (Jc) for high-{Tc} thin films, bicrystals, and bulk ceramics is shown to be determined by magnetic field penetration into the grain boundaries. The gross grain orientations may not in all cases be an important factor in determining this penetration. The parameter ({lambda}{sub G}/{lambda}{sub J}){sup 2} can characterize the strength of the grain boundary coupling, which depends mainly on the crystal coherence and connectivity at the boundary area.

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

    SciTech Connect

    Goncalves da Rocha, A.F. (Hospital Beneficencia Portuguesa, Rio de Janeiro, Brazil); 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. Radiation Effects in High Tc Superconductors for Space Applications

    Microsoft Academic Search

    W. G. Maisch; G. P. Summers; A. B. Campbell; C. J. Dale; J. C. Ritter; A. R. Knudson; W. T. Elam; H. Herman; J. P. Kirkland; R. A. Neiser; M. S. Osofsky

    1987-01-01

    YBa2Cu3O7 is one of the new class of superconductors having a critical temperature (Tc) above 90 K. Devices using these materials would require minimal refrigeration to operate in space. It is important, therefore, to determine the effect of natural space radiation on these materials. Preliminary experiments have been performed to study displacement damage and ionization effects in 100¿m thick films

  19. Radiation effects in high Tc superconductors for space applications

    Microsoft Academic Search

    W. G. Maisch; G. P. Summers; A. B. Campbell; C. J. Dale; J. C. Ritter

    1987-01-01

    YBa2Cu3O7 is a member of the class of superconductors whose critical temperatures (Tc) are above 90 K. Devices using these materials would require minimal refrigeration to operate in space. It is important, therefore, to determine the effect of natural space radiation on these materials. Preliminary experiments have been performed to study displacement damage and ionization effects in 100-micron-thick films of

  20. European project for the development of high TC current leads

    Microsoft Academic Search

    P. F. Herrmann; C. Albrecht; J. Bock; C. Cottevieille; S. Elschner; W. Herkert; M.-O. Lafon; H. Lauvray; A. Leriche; W. Nick; E. Preisler; H. Salzburger; J.-M. Tourre; T. Verhaege

    1993-01-01

    A European BRITE\\/EURAM project for the development of current leads in the kA range using high-TC superconductor parts has been started recently. The partners in this two-year project are two chemical companies, Hoechst and Rhone-Poulenc, and two companies in the field of electrical engineering, Siemens and Alcatel Alsthom. The goal of these four companies is to develop current leads for

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

    SciTech Connect

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

    2006-04-30

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

  2. Megaureter visualization on Tc-99m DMSA scintigraphy.

    PubMed

    Türkölmez, Seyda; Ors, Derya; Korkmaz, Meliha

    2005-07-01

    We present a patient with left-sided obstructed megaureter secondary to neuropathic bladder. He was referred for technetium-99m dimercaptosuccinic acid ((99m)Tc-DMSA) renal cortical scintigraphy to evaluate renal cortical function. Images obtained 4 hr after injection showed significant activity in the dilated left ureter. When the ureter is visualized on DMSA scan, obstructive megaureter should be considered in the differential diagnosis. PMID:16164201

  3. Tc-99m DMSA uptake by metastatic colorectal carcinoma.

    PubMed

    Rondogianni, Phivi; Koniaris, George

    2004-08-01

    Extrarenal uptake of Tc-99m DMSA is not seen very often. It has previously been described in metastatic disease and was mainly attributed to the presence of V-DMSA in the injected solution. We report a clinical case of incidental visualization of metastatic bone disease of the colon in a patient with renal failure. This could be the result of not only the presence of V-DMSA, but also the renal failure and the atypia of the lesions. PMID:15249824

  4. ''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.

  5. QCD over $T_c$: hadrons, partons and continuum

    E-print Network

    T. S. Biro; A. Jakovac

    2014-05-23

    In this paper we provide a physical picture for the QCD phase transition in terms of qualitative changes in the spectral functions. Our approach takes into account the crossover nature of this transition and counts for the observed strong correlation seen in higher order susceptibilities. We demonstrate that the hadron resonance gas, which alone describes the thermodynamics at temperatures $Talone quasiparticle gas. The conventional picture of a quark gluon plasma emerges only at $T\\geq 3T_c$.

  6. TC BEIRNE SCHOOL BIENNIAL REPORT 2008-2009

    E-print Network

    Blows, Mark

    .law.uq.edu.au/biennial-report ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ ­ Forgan Smith Building, St Lucia #12;Page 2 | TC Beirne School of Law Biennial Report 2008-2009 Research. Large Australian Research Council grants were awarded to Professor Brad Sherman and Dr David Morrison Schloenhardt (2008) and Dr David Morrison (2009) received a prestigious UQ Research Excellence Award ­ few

  7. Tc-99m HIDA scintigraphy in segmental biliary obstruction

    SciTech Connect

    Zeman, R.K.; Gold, J.A.; Gluck, L.; Caride, V.J.; Burrell, M.; Hoffer, P.B.

    1981-05-01

    Segmental biliary obstruction as a result of primary or secondary hepatic malignancy has been reported with increasing frequency. For two representative patients, the clinical and Tc-99m HIDA scintigraphic findings in segmetal biliary obstruction are described. The presence of photon-deficient dilated bile ducts in one segment of the biliary tree is highly suggestive of localized biliary obstruction and should be considered in the patient with suspected or proven hepatic malignancy despite the absence of jaundice.

  8. Tc-99m HIDA scintigraphy in segmental biliary obstruction

    SciTech Connect

    Zeman, R.K.; Gold, J.A.; Gluck, L.; Caride, V.J.; Burrell, M.; Hoffer, P.B.

    1981-05-01

    Segmental biliary obstruction as a result of primary or secondary hepatic malignancy has been reported with increasing frequency. For two representative patients, the clinical and Tc-99m HIDA scintigraphic findings in segmental biliary obstruction are described. The presence of photon-deficient dilated bile ducts in one segment of the biliary tree is highly suggestive of localized biliary obstruction and should be considered in the patient with suspected or proven hepatic malignancy despite the absence of jaundice.

  9. 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.

  10. Pressure Effects on Tc in Nb up to 40 GPa.

    NASA Astrophysics Data System (ADS)

    Struzhkin, V. V.; Hemley, R. J.; Mao, H. K.

    1997-03-01

    We have measured T_c(P) of Nb samples using a highly sensitive magnetic susceptibility technique adapted for measurements in diamond anvil cells. NaCl was used as a pressure medium. We observed an anomaly in T_c(P) for Nb at about 5-6 GPa, at which pressure the Tc increases by 0.7 K. Tc has a maximum 9.75 K at 10.5 GPa and decreases to 9.6 K at 14 GPa, then remains almost constant up to 40 GPa. Our results up to 5 GPa are compatible with previous measurements in piston-cylinder apparatus with a fluid pressure medium( T. F. Smith, Physics Letters, 33A), 465 (1970). to 2.4 GPa, which demonstrated linear decrease in Tc with -0.020 K/GPa. The anomaly might be related to a stress-sensitive topological electronic phase transition in Nb, or some unknown low-temperature structural transformation, and it explains previous controversial results for T_c(P) in Nb obtained with less hydrostatic pressure media.(W. Gey, Z. Phys. 229), 85 (1969).

  11. High-Tc SQUID magnetometer system with active cancellation

    NASA Astrophysics Data System (ADS)

    Kuriki, S.; Oyama, H.; Hayashi, A.; Washio, T.; Fujita, M.; Hirata, Y.

    2002-05-01

    Recent developments of high-Tc SQUIDs have enabled high sensitivity magnetometers to be used in wide range of places, such as laboratory and outdoor fields. At the early stage of developing multichannel system for measurement of magnetocardiogram (MCG) in clinical application, we have fabricated a single channel high-Tc SQUID magnetometer system. The system includes a direct-coupled SQUID with slot structure, a simple magnetically shielded room (MSR), and some active compensation electronics for the purpose of reducing various environmental field noises. A novel active noise cancellation was made by using a combination of a normal conducting detection coil that was horizontally wound in the middle height of the MSR, and two compensation coils that were wound at the top and bottom of the MSR. In addition, adaptive noise cancellation was supplemented by means of adaptive digital filter that was implemented in a digital signal processor. A total noise field attenuation of 50-60 dB was attained at 0.5-100 Hz. Low noise signals from the human heart were measured with a high-Tc SQUID in the noise reduced space in the MSR.

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

    SciTech Connect

    Maiti, Moumita; Lahiri, Susanta [Chemical Sciences Division, Saha Institute of Nuclear Physics, 1/AF, Bidhannagar, Kolkata 700 064 (India)

    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.

  13. Tc up to 50 K in superlattices of insulating oxides

    NASA Astrophysics Data System (ADS)

    Di Castro, D.; Aruta, C.; Tebano, A.; Innocenti, D.; Minola, M.; Moretti Sala, M.; Prellier, W.; Lebedev, O.; Balestrino, G.

    2014-04-01

    Here we report a structural and electronic investigation of the recently discovered CaCuO2/SrTiO3 superconducting artificial superlattices based on two insulating oxides. We show that Tc = 50 K is reached in the superlattices grown on NdGaO3 substrate under optimized growth conditions. If the superlattices are grown on LaAlO3 substrate the Tc is drastically reduced due to the much higher lattice mismatch between CaCuO2 and LaAlO3, which has lattice parameters substantially smaller than NdGaO3. The consequent in-plane lattice contraction also makes the incorporation of extra oxygen atoms more difficult, leading to a decrease of hole doping and Tc. Finally, x-ray absorption spectroscopy study as a function of the thickness of the CaCuO2 block in CaCuO2/SrTiO3 superconducting superlattices has revealed the important role played by the interfaces as the location of hole doping and superconductivity in these systems.

  14. 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.

  15. Radioisotopic detection of osseius metastases. Evaluation of 99mTc polyphosphate and 99mTc pyrophosphate.

    PubMed

    Fletcher, J W; Solaric-George, E; Henry, R E; Donati, R M

    1975-04-01

    A total of 146 patients were investigated for the presence of osseous metastases with 99mTc polyphosphate or 99mTc pyrophosphate bone scans. Results of bone imaging were retrospectively compared to roentgenographic results surveying similar anatomic areas in 128 patients. This comparison revealed that roentgenographic interpretations were in error in 19% of the cases. Thirty-three patients had bone scans and roentgenograms that were in agreement and considered abnormal, but in more than one third of these cases the patients had multiple abnormalities that were shown by the bone scan but were not recognized roentgenographically. In consideration of the low toxicity, ready availability, economy, shortened procedure time, and low radiation dose associated with the use of these new bone-seeking agents, it is concluded that they are superior to roentgenograms and previously utilized radionuclides for early detection of osseous metastases. PMID:166626

  16. 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

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

    E-print Network

    Prozorov, Ruslan

    such as SR or revers- ible magnetization. Our method has been tested on single crystals of YBa2Cu3O7 YBCO-Tc superconductive coating R. Prozorova) and R. W. Giannetta Loomis Laboratory of Physics, University of Illinois), from the frequency shift of a resonator. The technique involves coating a high-Tc superconductor

  18. Clinical comparison of diisopropyl-IDA Tc 99m and diethyl-IDA Tc 99m for evaluation of the hepatobiliary system

    SciTech Connect

    Klingensmith, W.C.; Fritzberg, A.R.; Spitzer, V.M.; Kuni, C.C.; Shanahan, W.S.

    1981-09-01

    Thirty-one patients with a wide range of hepatobiliary function and clinical diagnoses were studied with both diisopropyl-IDA Tc 99m and diethyl-IDA Tc 99m. Images were similar except for an increased liver-to-kidney ratio with diisopropyl-IDA Tc 99m (p less than 0.01) and a tendency toward an increased liver-to-background ratio at five minutes with diisopropyl-IDA Tc 99m (p greater than 0.05). Quantification of the relative hepatocyte extraction efficiency indicated a 16% higher extraction efficiency for diisopropyl-IDA Tc 99m (p greater than 0.05). Cumulative three-hour urine collections following injection demonstrated no significant difference in renal excretion in patients with normal total serum bilirubin levels. Both radiopharmaceuticals demonstrated increasing renal excretion with increasing total serum bilirubin levels; however, renal excretion of diisopropyl-IDA Tc 99m increased more slowly than excretion of diethyl-IDA Tc 99m (p less than 0.01). We conclude that, while the overall differences between these two radiopharmaceuticals are small, diisopropyl-IDA Tc 99m is superior because of a lower renal excretion rate in patients with decreased hepatocyte function.

  19. Studies of the retention mechanism of the brain perfusion imaging agent {sup 99m}{Tc}-bicisate ({sup 99m}{Tc}-ECD)

    SciTech Connect

    Walovitch, R.C.; Cheesman, E.H.; Maheu, L.J.; Hall, K.M. [DuPont Merck Pharmaceutical Co., North Billerica, MA (United States)

    1994-01-01

    The structure-activity relationship in a series of analogues of {sup 99m}{Tc}-bicisate ({sup 99m}{Tc}-N,N{prime}-1,2-ethylene-diylbis-L-cysteine diethyl ester dihydrochloride, RP-217) is described using in vivo studies in rodent and primate brain tissue. All analogues investigated were {sup 99m}{Tc}-diamine dithiol diesters, which were neutral and lipophilic and had modified brain uptake indexes ({ge}40) suggesting adequate first-pass extraction. All analogues were poorly retained by the rodent brain. In contrast, the stereochemistry and structure of the {sup 99m}{Tc}-complexes affected their brain retention in primates. All compounds that demonstrated selective primate brain retention were L-diesters that were metabolized in primate brain tissue to nonlypophilic complexes resulted from ester hydrolysis. Unretained complexes were not metabolized in primate brain tissue. More extensive studies were performed with {sup 99m}{Tc}-bicisate, which demonstrated poor brain retention in several nonprimate species (i.e., dogs, ferrets, pigs, and rodents). In rodent and nonhuman primate tissue, {sup 99m}{Tc}-bicisate was rapidly metabolized to a monoacid ester ({sup 99m}{Tc}-N,N{prime}-1,2-ethylenediylbis-L-cysteine monoethyl ester). Therefore, brain metabolism of {sup 99m}{Tc}-bicisate results in the formation of an acid product(s) that is selectively trapped in primate brain. 20 refs., 2 figs., 4 tabs.

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

    SciTech Connect

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

    1985-05-01

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

  1. /sup 99m/Tc-glucoheptonate for quantitation of differential renal function

    SciTech Connect

    Ziessman, H.A.; Balseiro, J.; Fahey, F.H.; Le, T.V.; Dubiansky, V.

    1987-05-01

    Differential renal function was calculated by using /sup 99m/Tc-glucoheptonate (Tc-GH) in 51 patients. Computer-acquired background-corrected individual renal function was calculated by using both the 1-3-min uptake counts and the 2-4-hr delayed static counts. The degree of correlation between the two was high (r = .96). An equally high correlation was noted in 16 children who were 12 years old or younger, in 15 patients with renal size disparity greater than 60/40%, and in six patients with abnormal creatinine clearances. Ten patients had a 30-min dynamic /sup 99m/Tc-DTPA study followed immediately by the injection of Tc-GH and acquisition of delayed static images 2-4 hr later. A high degree of correlation (r = .99) was seen between the 1-3-min differential function obtained by using Tc-DTPA and the 2-4-hr delayed differential function obtained by using Tc-GH. This study shows that Tc-GH is a clinically useful and valid tool for calculation of differential renal function and that Tc-GH combines many of the best aspects of Tc-DTPA and Tc-DMSA.

  2. TC1(C8orf4) Regulates Hematopoietic Stem/Progenitor Cells and Hematopoiesis

    PubMed Central

    Lee, Soyoung; Kim, Jungtae; Park, Surim; Song, Kyuyoung; Lee, Inchul

    2014-01-01

    Hematopoiesis is a complex process requiring multiple regulators for hematopoietic stem/progenitor cells (HSPC) and differentiation to multi-lineage blood cells. TC1(C8orf4) is implicated in cancers, hematological malignancies and inflammatory activation. Here, we report that Tc1 regulates hematopoiesis in mice. Myeloid and lymphoid cells are increased markedly in peripheral blood of Tc1–deleted mice compared to wild type controls. Red blood cells are small-sized but increased in number. The bone marrow of Tc1?/? mice is normocellular histologically. However, Lin?Sca-1+c-Kit+ (LSK) cells are expanded in Tc1?/? mice compared to wild type controls. The expanded population mostly consists of CD150?CD48+ cells, suggesting the expansion of lineage-restricted hematopoietic progenitor cells. Colony forming units (CFU) are increased in Tc1?/? mice bone marrow cells compared to controls. In wild type mice bone marrow, Tc1 is expressed in a limited population of HSPC but not in differentiated cells. Major myeloid transcriptional regulators such as Pu.1 and Cebp? are not up-regulated in Tc1?/? mice bone marrow. Our findings indicate that TC1 is a novel hematopoietic regulator. The mechanisms of TC1-dependent HSPC regulation and lineage determination are unknown. PMID:24937306

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

    SciTech Connect

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

    2007-07-01

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

  4. Soil availability, plant uptake and soil to plant transfer of 99Tc--a review.

    PubMed

    Bennett, Roy; Willey, Neil

    2003-01-01

    The fission yield of 99Tc from 239Pu and 235U is similar to that of 137Cs or 90Sr and it is therefore an important component of nuclear weapons fall-out, nuclear waste and releases from nuclear facilities. There is particular current interest in 99Tc transfer from soil to plants for: (a) environmental impact assessments for terrestrial nuclear waste repositories, and (b) assessments of the potential for phytoextraction of radionuclides from contaminated effluent and soil. Vascular plants have a high 99Tc uptake capacity, a strong tendency to transport it to shoot material and accumulate it in vegetative rather than reproductive structures. The mechanisms that control 99Tc entry to plants have not been identified and there has been little discussion of the potential for phytoextraction of 99Tc contaminated effluents or soil. Here we review soil availability, plant uptake mechanisms and soil to plant transfer of 99Tc in the light of recent advances in soil science, plant molecular biology and phytoextraction technologies. We conclude that 99Tc might not be highly available in the long term from up to 50% of soils worldwide, and that no single mechanism that might be easily targeted by recombinant DNA technologies controls 99Tc uptake by plants. Overall, we suggest that Tc might be less available in terrestrial ecosystems than is often assumed but that nevertheless the potential of phytoextraction as a decontamination strategy is probably greater for 99Tc than for any other nuclide of radioecological interest. PMID:12527237

  5. Tc1 transposase of Caenorhabditis elegans is an endonuclease with a bipartite DNA binding domain.

    PubMed Central

    Vos, J C; Plasterk, R H

    1994-01-01

    The Tc1 transposon of Caenorhabditis elegans is a member of the Tc1/mariner family of mobile elements. These elements have inverted terminal repeats that flank a single transposase gene. Here we show that Tc1 transposase, Tc1A, has a bipartite DNA binding domain related to the paired domain of mammalian and Drosophila genes. Both the DNA binding domain of Tc1A and the DNA binding site in the inverted repeat of Tc1 can be divided into two subdomains. Methylation interference studies demonstrate adjacent minor and major groove contacts at the inner part of the binding site by the N-terminal 68 amino acids of the DNA binding domain. In addition, Tc1A amino acids 69-142 are essential for major groove contacts at the outer part of the binding site. Recombinant Tc1A is found to be able to introduce a single strand nick at the 5' end of the transposon in vitro. Furthermore, Tc1A can mediate a phosphoryl transfer reaction. A mutation in a DDE motif abolishes both endonucleolytic and phosphoryl transfer activities, suggesting that Tc1A carries a catalytic core common to retroviral integrases and IS transposases. Images PMID:7813449

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

    SciTech Connect

    Luo, Y. X. [Physics Department, Vanderbilt University, Nashville, Tennessee 37235 (United States); Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Hamilton, J. H.; Ramayya, A. V.; Hwang, J. K.; Gore, P. M.; Jones, E. F.; Fong, D. [Physics Department, Vanderbilt University, Nashville, Tennessee 37235 (United States); Rasmussen, J. O.; Lee, I. Y. [Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Stefanescu, I. [KU Leuven, Instituut voor Kern- en Stralingsfysica, Celestijnenlaan 200D, B-3001 Leuven (Belgium); Che, X. L. [Physics Department, Tsinghua University, Beijing 100084 (China); Zhu, S. J. [Physics Department, Vanderbilt University, Nashville, Tennessee 37235 (United States); Physics Department, Tsinghua University, Beijing 100084 (China); Joint Institute for Heavy Ion Research, Oak Ridge, Tennessee 37831 (United States); Wu, S. C. [Department of Physics, National Tsing Hua University, Hsinchu, Taiwan (China); Ginter, T. N. [Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824 (United States); Ma, W. C. [Mississippi State University, Drawer 5167, Mississippi State, Mississippi 39762 (United States); Ter-Akopian, G. M.; Daniel, A. V. [Flerov Laboratory for Nuclear Reactions, JINR, Dubna (Russian Federation); Stoyer, M. A. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Donangelo, R. [Universidade Federal do Rio de Janeiro, CP 68528, RG (Brazil); Gelberg, A. [Institut fuer Kernphysik, Universitaet zu Koeln, D-50937, Cologne (Germany)

    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.

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

    PubMed

    Leplat, N; Rossi, M J

    2014-07-17

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

  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. Tetraamine-coupled peptides and resulting (99m)Tc-radioligands: an effective route for receptor-targeted diagnostic imaging of human tumors.

    PubMed

    Nock, Berthold; Maina, Theodosia

    2012-01-01

    The successful application of OctreoScan(®) ([(111)In-DTPA]octreotide) in the diagnosis of sst(2)-expressing neuroendocrine tumors (NETs), on one hand, and the manifestation of peptide receptor targets in a wide range of human cancers, on the other, have synergistically induced a booming emergence of numerous radiolabeled peptide (radiopeptide) probes for tumor diagnosis and therapy in man. Definition of molecular targets and their relation to neoplastic disease has preceded peptide-based radiopharmaceutical design and development. New criteria have been set to safeguard efficient localization of radionuclides on tumor-associated high affinity - low capacity peptide receptor systems. New technical and biological terms, such as specific activity or receptor affinity and internalization, have invaded the Radiopharmacy domain and have irrevocably altered our concept of radiopharmaceutical design. Nonetheless, (99m)Tc remains the gold standard of diagnostic nuclear medicine as a result of ideal nuclear characteristics, cost-effectiveness and wide availability in high purity and high specific activity by means of commercial (99)Mo/(99m)Tc-generators. The evolution of conventional (99m)Tc-perfusion agents into modern state-of-the-art molecular radiopharmaceuticals has been a challenge addressed by several researchers. The present review summarizes recent advances in the development of (99m)Tc-labeled peptides for in vivo targeting of neoplastic disease, and, in particular, those functionalized with acyclic tetraamines. Conclusions on their applicability in non-invasive diagnosis and staging of cancer patients are drawn. PMID:23339761

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

    PubMed Central

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

    2009-01-01

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

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

    PubMed

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

    1995-02-01

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

  12. 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

  13. Second-generation thyrotropin receptor antibodies assay and quantitative thyroid scintigraphy in autoimmune hyperthyroidism.

    PubMed

    Giovanella, L; Ceriani, L; Ghelfo, A

    2008-07-01

    Graves' disease (GD) is characterized by circulating TSH receptor antibodies (TRAb), and so-called hyperthyroid autoimmune thyroiditis (H-AIT) generally shows negative TRAb results with first-generation assays. However, a positive titer was observed in up to 13% of patients with euthyroid or hypothyroid autoimmune thyroiditis (AIT) by second-generation TRAb assays, and a larger increase is expected in hyperfunctioning forms. A thyroid 99mTc-pertechnetate uptake (TcTUs) cutoff of 2% previously was shown to accurately discriminate between GD and H-AIT. Here we evaluated the relationship between second-generation TRAb assays and TcTUs in 139 patients with untreated autoimmune hyperthyroidism. An increase in TRAb levels was found in 114 of 139 patients (82%). All patients with TcTUs >2% and 66% of those with lower values had positive TRAb measurements. When the cutoff was increased to 5.9 U/l, positive TRAb occurred in 92.6% of those having higher TcTUs and in 1.4% of those with lower TcTUs. TRAb levels significantly increased in patients with TcTUs higher than 2% as compared with those having lower values, while no differences occurred in patients with TcTUs ranging from 0 to 1%, from 1.1 to 1.5%, or from 1.6 to 2%. A significant relationship between TRAb and TcTUs (as well as fT3, fT4, and thyroid volume) was found. TcTUs, fT4, fT3, and thyroid volume significantly increased in patients with positive TRAb (cutoff 1.5 U/l) compared with those testing negative. Our data indicate that a large proportion of patients with hyperthyroidism and hypoechoic thyroid, including those previously diagnosed as having H-AIT, actually have circulating TRAb. TRAb levels predicate the degree of iodine uptake (as measured by TcTUs) and thyroid hyperfunction. The role of baseline TRAb measurement by second-generation assays to predict patients' outcome needs to be further evaluated and compared with TcTUs in prospective studies. PMID:18393171

  14. Justification of administered dose level in brain perfusion imaging with 99mTc-HMPAO

    NASA Astrophysics Data System (ADS)

    Stefanoyiannis, A. P.; Gerogiannis, I.; Geronikola-Trapali, X.; Armeniakos, I.; Prentakis, A.; Soultanis, S.; Chatziioannou, S. N.

    2011-09-01

    Brain perfusion imaging by means of 99mTc-HMPAO is widely used in the diagnosis of Alzheimer's disease. The administered dose range recommended by the manufacturer and reported in bibliography is rather wide (~ 9.5 - 27 mCi), necessitating further quantitative analysis. In the framework of this study, a quantitative evaluation of the radiopharmaceutical performance for different values of administered dose was carried out, based on image quality indicators. Evaluation of image quality was based on wavelet-generated contrast, noise, and contrast-to-noise ratio indicators, denoted as CI, NI and CNR respectively. Subsequently, a generic image quality index was correlated with the administered dose, to produce an overall performance indicator (denoted as PI). Application of appropriate statistical tests (analysis of variance for normal and Kruskal-Wallis test for non-normal distributions) showed that there is a statistically significant difference in CI (p < 0.01), NI (p < 0.001) and CNR (p < 0.05), but not in PI (p > 0.05) values. Application of Tukey test for CI and NI normal distributions demonstrated that CI (10 mCi) = CI (20 mCi) < CI (15 mCi) and NI (10 mCi) > NI (20 mCi), while NI (15 mCi) could not be characterised. Finally, application of non-parametric multiple comparisons showed that CNR (20 mCi) < CNR (10 mCi), while CNR (15 mCi) could not be characterised. Consequently, brain perfusion imaging, by means of 99mTc-HMPAO utilising an administered dose of 20 mCi, results in improved image quality on the basis of the estimated indicators. Additionally, this image quality improvement is sufficient to justify the increased patient radiation burden.

  15. Is there still a need for Tc-99m DMSA renal imaging?

    PubMed

    Bair, H J; Becker, W; Schott, G; Kühn, R H; Wolf, F

    1995-01-01

    Scintigraphy with Tc-99m MAG3 is, to date, the most commonly used technique for evaluating separate renal function (SRF). In this study, the performance of this technique is compared to Tc-99m DMSA. A total of 37 patients with various kidney disorders (12 children and 25 adults) underwent both Tc-99m DMSA and Tc-99m MAG 3 scintigraphy. In children and adults of normal weight the correlation coefficient between the two methods was 0.99 (P < 0.001), whereas in individuals who were more than 10% overweight according to Broca, or who had abnormal anatomical positions of the kidneys, the correlation coefficient was 0.82 (P < 0.05). Scintigraphy with Tc-99m DMSA was more accurate in renal parenchyma lesions. These results indicate that Tc-99m DMSA scintigraphy is preferable for the evaluation of SRF in patients who are more than 10% overweight, or have abnormal positions of the kidneys. PMID:7895429

  16. Hepatocellular carcinoma: uptake of /sup 99m/Tc-IDA in primary tumor and metastasis

    SciTech Connect

    Lee, V.W.; O'Brien, M.J.; Devereux, D.F.; Morris, P.M.; Shapiro, J.H.

    1984-07-01

    Four consecutive cases of proven hepatocellular carcinoma (HCC) showed significant avidity of /sup 99m/Tc-labeled iminodiacetic acids (Tc-IDAs) in preoperative scintigraphy. In one patient, the pulmonary metastasis showed uptake of Tc-IDA. Such scintigraphic findings were obvious only in the delayed scans, performed 2 1/2 - 4 hr after injection. Since Tc-IDAs and bilirubin are functional analogs physiologically, the ability of HCC to concentrate Tc-IDAs may be related to the ability of HCC neoplastic cells to form bile intracellularly. This hypothesis is supported by the fact that intracellular bile granules were found in the tumor cells of all four patients. This suggests a potential for using Tc-IDAs for the specific and preoperative diagnostic of HCC.

  17. Hepatocellular carcinoma: uptake of /sup 99/mTc-IDA in primary tumor and metastasis

    SciTech Connect

    Lee, V.W.; O'Brien, M.J.; Devereux, D.F.; Morris, P.M.; Shapiro, J.H.

    1984-07-01

    Four consecutive cases of proven hepatocellular carcinoma (HCC) showed significant avidity of /sup 99/mTc -labeled iminodiacetic acids (Tc- IDAs ) in preoperative scintigraphy. In one patient, the pulmonary metastasis showed uptake of Tc-IDA. Such scintigraphic findings were obvious only in the delayed scans, performed 2 1/2-4 hr after injection. Since Tc- IDAs and bilirubin are functional analogs physiologically, the ability of HCC to concentrate Tc- IDAs may be related to the ability of HCC neoplastic cells to form bile intracellularly. This hypothesis is supported by the fact that intracellular bile granules were found in the tumor cells of all four patients. This suggests a potential for using Tc- IDAs for the specific and preoperative diagnostic of HCC.

  18. Dark Energy Stars, AdS/CFT, and High Tc

    E-print Network

    George Chapline

    2010-02-24

    As developed previously the physical behavior of space-time near to an event horizon can be surmised from the behavior of a superfluid near to a critical point where the speed of sound vanishes. In this talk we note that this critical behavior can be given a geometrical interpretation by regarding the tuning parameter as a radial coordinate for anti-de Sitter space. We also draw attention to a mathematical model for a layered conductor with strong spin-orbit interactions which provides a physical explanation for why the behavior of space-time near an event horizon is related to the behavior of high Tc superconductors.

  19. 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.

  20. Sclerosing cholangitis: cholescintigraphy with Tc-99m-labeled DISIDA

    SciTech Connect

    Ament, A.E.; Bick, R.J.; Miraldi, F.D.; Haaga, J.R.; Wiedenmann, S.D.

    1984-04-01

    Four patients with primary sclerosing cholangitis (PCS) were examined with the hepatobiliary agent Tc-99m-labeled DISIDA (diisopropylphenylcarbamoyl iminodiacetic acid), and the results correlated with those of invasive cholangiography. Cholescintigraphy is superior to cholangiography in cases of suspected PSC where there is nonfilling of biliary radicals due to high-grade stenosis. The finding of delayed hepatic parenchymal clearance can allow estimation of the degree of obstruction of the various branches of the major bile ducts. Cholescintigraphy offers a noninvasive method of investigating patients with suspected sclerosing chloangitis, leading to earlier diagnosis. Confirmation with invasive cholangiographic procedures is recommended.

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

    PubMed Central

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

    2012-01-01

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

  2. Inter and Intraobserver Variability of 99mTc-DMSA Renal Scintigraphy: Impact of Oblique Views

    Microsoft Academic Search

    Meltem Caglar; Ozgen Kiratli; Erdem Karabulut

    2007-01-01

    99mTc-Dimercaptosuccinic acid (DMSA) scintigraphy is a fre- quently used diagnostic test to assess the presence and severity of cortical damage. The aim of this study is to investigate the var- iability in the interpretation of 99mTc-DMSA scans, evaluate the usefulness of oblique images, and assess their impact on scan interpretation. Methods: Two experienced nuclear medicine physicians independently interpreted 100 99mTc-DMSA

  3. A 99mTc-Labeled Triphenylphosphonium Derivative for the Early Detection of Breast Tumors

    PubMed Central

    Li, Zhixin; Lopez, Marcos; Hardy, Micaël; McAllister, Donna M.; Kalyanaraman, Balaraman

    2009-01-01

    Abstract Introduction A greater mitochondrial membrane potential in tumor cells has been shown to enhance the accumulation of triphenyl phosphonium derivatives. The aim of this study was to synthesize and characterize 99mTc-labeled alkyl triphenyl phosphonium (99mTc-Mito10-MAG3) for the early detection of breast tumors. Methods Mito10-MAG3 was synthesized by coupling (10-aminodecyl)triphenyl phosphonium bromide with NHS-MAG3 and radiolabeled with 99mTc. Biodistribution and pharmacokinetics of 99mTc-Mito10-MAG3 was investigated in female Sprague-Dawley rats. Initially, 99mTc-Mito10-MAG3 was tested in animals with established breast tumors. In a subsequent longitudinal study, the imaging efficacy of 99mTc10-Mito-MAG3 for detecting small, nonpalpable breast tumors was assessed after chemically inducting breast carcinoma. Tumors detected by imaging were allowed to grow to palpable size and confirmed by histology. The results were compared with 99mTc-MIBI. Results The synthesis of Mito10-MAG3 was confirmed by mass spectrometry. The compound was radiolabeled with 99mTc to >?92% in a single step. The radiopharmaceutical exhibited fast blood clearance and low cardiac uptake. In the initial study, using animals with established breast tumors, 99mTc-Mito10-MAG3 imaging detected small lesions that were missed by palpation. In the longitudinal study, 99mTc-Mito10-MAG3 exhibited focal uptake in small breast tumors, which were confirmed by histology. Conclusions Imaging, using 99mTc-Mito10-MAG3, allowed the early detection of small neoplastic lesions in the mammary glands. The agent significantly reduced cardiac uptake, compared with 99mTc-MBIB. The phosphonium-based derivatives warrant further characterization and development as imaging agents for scintimammography. PMID:19877888

  4. Inhomogeneous Superconducting State and intrinsic Tc : Near Room Temperature Superconductivity in the Cuprates

    Microsoft Academic Search

    Vladimir Z. Kresin; Stuart A. Wolf

    2011-01-01

    Doped cuprates are inhomogeneous superconductors. The concept of an intrinsic critical temperature, Tcintr.$\\\\equiv$ Tc*, whose value greatly exceeds that for the resistive Tcres.$\\\\equiv$ Tc, is supported by a number of experimental studies, including those performed recently. These data are discussed in this review. The anomalous diamagnetism observed at Tcres.$\\\\equiv$ Tc* is a manifestation of the presence of superconducting clusters

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

    PubMed Central

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

    2013-01-01

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

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

    PubMed Central

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

    2013-01-01

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

  7. Congenital renal anomaly: evaluation with 99mTc-dimercaptosuccinic acid renal scintigraphy

    SciTech Connect

    Hosokawa, S.; Kawamura, J.; Tomoyoshi, T.; Yoshida, O.

    1983-05-01

    Technetium 99m-2,3, dimercaptosuccinic acid (99mTc-DMSA) preferentially accumulates in the renal cortex, demonstrating functioning cortical mass. We used 99mTc-DMSA renal scintigraphy in ten patients with horseshoe kidneys and five patients with unilateral fused kidneys. The results show that 99mTc-DMSA renal scintigraphy reliably establishes the diagnosis of horseshoe kidney and clearly shows the isthmus, which is very essential for proper management. The technique also aids in the definitive assessment of separate kidney function and of total radionuclide uptake is possible using 99mTc-DMSA scintigraphy.

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

    SciTech Connect

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

    1989-08-01

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

  9. Differential uptake of Tc-99m DMSA and Tc-99m EC in renal tubular disorders: Report of two cases and review of the literature

    PubMed Central

    Reddy Gorla, Arun Kumar; Agrawal, Kanhaiyalal; Sood, Ashwani; Bhattacharya, Anish; Mittal, Bhagwant Rai

    2014-01-01

    Tc-99m DMSA and Tc-99m EC studies are invaluable functional imaging modalities for renal structural and functional assessment. Normally, the relative renal function estimated by the two methods correlates well with each other. We here present two patients with renal tubular acidosis who showed impaired/altered DMSA uptake with normal EC renal dynamic study depicting the pitfall of DMSA imaging in tubular disorders. The two presented cases also depict distinct pattern of Tc-99m DMSA scintigraphic findings in patients with proximal and distal renal tubular acidosis, thus highlighting the factors affecting DMSA kinetics. PMID:25210282

  10. Differential uptake of Tc-99m DMSA and Tc-99m EC in renal tubular disorders: Report of two cases and review of the literature.

    PubMed

    Reddy Gorla, Arun Kumar; Agrawal, Kanhaiyalal; Sood, Ashwani; Bhattacharya, Anish; Mittal, Bhagwant Rai

    2014-07-01

    Tc-99m DMSA and Tc-99m EC studies are invaluable functional imaging modalities for renal structural and functional assessment. Normally, the relative renal function estimated by the two methods correlates well with each other. We here present two patients with renal tubular acidosis who showed impaired/altered DMSA uptake with normal EC renal dynamic study depicting the pitfall of DMSA imaging in tubular disorders. The two presented cases also depict distinct pattern of Tc-99m DMSA scintigraphic findings in patients with proximal and distal renal tubular acidosis, thus highlighting the factors affecting DMSA kinetics. PMID:25210282

  11. Generating functions Moment generating functions

    E-print Network

    Adler, Robert J.

    generating functions MX(t) = E etX = x etx pX(x) X Bernoulli, parameter p MX(t) = et p + e0 q = pet + q X' & $ % Lecture 21 Generating functions Moment generating functions Moments and the MGF Sums of independent variables Characteristic functions Probability generating functions 1 #12;' & $ % Generating

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

    NASA Astrophysics Data System (ADS)

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

    2010-06-01

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

  13. Characterization of high Tc superconductor by luminescence methods

    NASA Astrophysics Data System (ADS)

    Fujiwara, Yasufumi; Kobayashi, Takeshi

    1989-03-01

    High-Tc superconductors have been investigated by photoluminescence (PL) and X-ray excited thermally stimulated luminescence (TSL) techniques. Characteristic PLs have been observed in the infrared region in the Er-Ba-Cu-O and Nd-Ba-Cu-O systems, which are tentatively assigned to electronic transitions between weakly crystal-field-split spin-orbit levels of trivalent Er and Nd ions. The spectral shapes and/or peak positions are dependent on the crystal arrangement surrounding the rare-earth ion. Such PLs have never been obtained in the Eu-Ba-Cu-O and Yb-Ba-Cu-O systems. TSL measurements have been performed with particular emphasis on the Gd-Ba-Cu-O system. Characteristic TSLs have been observed in this system, depending on the composition, preparation conditions and cumulative X-ray irradiation time. The activation energy of the related traps ranges from 0.1 eV to 0.3 eV. Characteristic TSLs have also been observed in the Ho-Ba-Cu-O and new high-Tc superconducting systems containing no rare-earth elements.

  14. 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.

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

    PubMed

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

    2003-08-01

    Calculation of iodine-131 activities for radioiodine treatment (RIT) in patients with disseminated thyroid autonomy may be difficult because of uncertainties in the determination of the autonomous volume (vol(aut)). The algorithm established by Emrich is used for calculation of the vol(aut) based on the TcTUs (technetium thyroid uptake under TSH suppression) (vol(aut)= 5xTcTUs+0.6). Clinical experience using this approach has shown that there is a negative correlation between increasing TcTUs and the results of RIT. Our aim was to identify the reasons for this observation as well as to assess the relation between TcTUs and sonographic vol(aut). Furthermore, we intended to find an alternative algorithm for the TcTUs-based calculation of the vol(aut). Data from 100 patients with unifocal autonomy who met strict inclusion criteria were used to evaluate the correlation between TcTUs and sonographic vol(aut). Using Marinelli's algorithm, we calculated the therapeutic activities for a standardised patient at a target dose of 300 Gy. The vol(aut) was determined based on the TcTUs using the four published algorithms [Emrich 1993 (vol(aut)= 5xTcTUs+0.6), Kreisig 1992 (vol(aut)=10xTcTUs-9.3), Joseph 1977 (vol(aut)=8.33xTcTUs-6.67) and 1994 (vol(aut)=2.88xTcTUs+0.09)]. We then compared the results of the calculation of therapeutic activities obtained using Emrich's algorithm (with known success rates) with those obtained by the other algorithms in order to determine which algorithm would lead to better results in RIT. Only a weak correlation was found between the TcTUs and the sonographic vol(aut) ( r(2)=0.39). The calculated therapeutic activities of (131)I were similar for all algorithms at a TcTUs of around 2% but Joseph's (1977) and Kreisig's (1992) algorithms resulted in clearly higher activities than Emrich's algorithm at a TcTUs above 2%. The need for target doses to increase with TcTUs in RIT may be overcome by the use of adequate algorithms for determination of the vol(aut). The algorithm published by Joseph and co-workers in 1977 probably offers the most reliable approach to the TcTUs-based calculation of vol(aut) in RIT. In contrast to the other algorithms, it is based on autoradiographic planimetric data. Thus, it takes into account the polyclonal origin of thyroid nodules as well as the presence of regressive or cystic changes. The well-established algorithm of Emrich underestimates the true vol(aut), which explains the decreasing success of RIT with increasing TcTUs. PMID:12827311

  16. 1. Generation 1 1. Generation

    E-print Network

    Berlin,Technische Universität

    1. Generation 1 _________________________________________________________________________ 1. Generation Sound and vibrations or, in more general terms, oscillations of matter (solids or fluids) are generated in many different dynamic processes. The basic mechanisms which underlie these oscillations

  17. 99mTc-Labeled HYNIC-DAPI Causes Plasmid DNA Damage with High Efficiency

    PubMed Central

    Kotzerke, Joerg; Punzet, Robert; Runge, Roswitha; Ferl, Sandra; Oehme, Liane; Wunderlich, Gerd; Freudenberg, Robert

    2014-01-01

    99mTc is the standard radionuclide used for nuclear medicine imaging. In addition to gamma irradiation, 99mTc emits low-energy Auger and conversion electrons that deposit their energy within nanometers of the decay site. To study the potential for DNA damage, direct DNA binding is required. Plasmid DNA enables the investigation of the unprotected interactions between molecules and DNA that result in single-strand breaks (SSBs) or double-strand breaks (DSBs); the resulting DNA fragments can be separated by gel electrophoresis and quantified by fluorescent staining. This study aimed to compare the plasmid DNA damage potential of a 99mTc-labeled HYNIC-DAPI compound with that of 99mTc pertechnetate (99mTcO4?). pUC19 plasmid DNA was irradiated for 2 or 24 hours. Direct and radical-induced DNA damage were evaluated in the presence or absence of the radical scavenger DMSO. For both compounds, an increase in applied activity enhanced plasmid DNA damage, which was evidenced by an increase in the open circular and linear DNA fractions and a reduction in the supercoiled DNA fraction. The number of SSBs elicited by 99mTc-HYNIC-DAPI (1.03) was twice that caused by 99mTcO4? (0.51), and the number of DSBs increased fivefold in the 99mTc-HYNIC-DAPI-treated sample compared with the 99mTcO4? treated sample (0.02 to 0.10). In the presence of DMSO, the numbers of SSBs and DSBs decreased to 0.03 and 0.00, respectively, in the 99mTcO4– treated samples, whereas the numbers of SSBs and DSBs were slightly reduced to 0.95 and 0.06, respectively, in the 99mTc-HYNIC-DAPI-treated samples. These results indicated that 99mTc-HYNIC-DAPI induced SSBs and DSBs via a direct interaction of the 99mTc-labeled compound with DNA. In contrast to these results, 99mTcO4? induced SSBs via radical formation, and DSBs were formed by two nearby SSBs. The biological effectiveness of 99mTc-HYNIC-DAPI increased by approximately 4-fold in terms of inducing SSBs and by approximately 10-fold in terms of inducing DSBs. PMID:25098953

  18. 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.

  19. Single-crystal EPR, 35,37Cl and 14,15N ENDOR and ESEEM studies on (Ph 4As)[Tc VINCl 4/Tc VOCl 4]. I. Single-crystal EPR on (Ph 4As)[Tc 14,15NCl 4/TcOCl 4], and crystal structure of (Ph 4As)[TcOCl 4

    NASA Astrophysics Data System (ADS)

    Kirmse, R.; Köhler, K.; Abram, U.; Böttcher, R.; Goli?, L.; De Boer, E.

    1990-05-01

    A single-crystal EPR study of tetraphenylarsoniumtetrachloro nitrido-technetate (VI), (Ph 4As) [Tc 15NCl 4], diamagnetically diluted by the isoelectronic oxotechnetate (V) complex, and the crystal structure of the host complex are reported. (Ph 4As) [TcOCl 4] crystallizes tetragonal, space group P4/n, Z=2 with a= b= 12.670(1) and c=7.824(1) Å. The anion possesses C 4v symmetry. The EPR spectra are typical of an ion with a 4d 1 configuration. At low temperatures very complex 35,37Cl and 15N ligand hyperfine patterns are observed. The 99Tc, 35,37Cl and 15N hyperfine data are analyzed to evaluate the electron spin delocalization: 20% of the spin density is localized in mainly the 3p orbitals of the Cl atoms.

  20. Electrical generation

    NSDL National Science Digital Library

    Iowa Public Television. Explore More Project

    2004-01-01

    How is electricity generated? This reading, part of a series about the future of energy, introduces students to the production of electricity using a generator. Students read about the movement of electrons called current electricity. Static electricity is also discussed. Students follow as the generation of electric current is described using magnets in a generator. Copyright 2005 Eisenhower National Clearinghouse

  1. Liver visualization following 99m Tc-MAA ( 99m Tc-macroaggregated albumin) venogram indicating obstruction of the distal inferior vena cava

    Microsoft Academic Search

    Zvi H. Oster; Harold L. Atkins

    1985-01-01

    Uniform visualization of the liver following the injection of 99mTc-MAA for lower-limb venography and the appearance of activity in the paravertebral plexus are indicative of distal inferior vena cava (IVC) obstruction.

  2. 99mTc-3P4-RGD2 Scintimammography in the Assessment of Breast Lesions: Comparative Study with 99mTc-MIBI

    PubMed Central

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

    2014-01-01

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

  3. 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

  4. Biodistribution and dosimetry of 99mTc-ciprofloxacin, a promising agent for the diagnosis of bacterial infection.

    PubMed

    De Winter, F; Van de Wiele, C; Dumont, F; Van Durme, J; Solanki, K; Britton, K; Slegers, G; Dierckx, R A; Thierens, H

    2001-05-01

    This study reports on the biodistribution and dosimetry of technetium-99m ciprofloxacin, a radio-ligand developed for the visualisation of bacterial infection. Whole body scans were performed up to 24 h after intravenous injection of 370 MBq 99mTc-ciprofloxacin in three male and three female volunteers. Blood samples were taken at various times up to 24 h after injection. Urine was also collected up to 24 h after injection, allowing calculation of renal clearance and interpretation of whole body clearance. Time-activity curves were generated for the thyroid, heart, liver and whole body by fitting the organ-specific geometric mean counts, obtained from regions of interest. The MIRD formulation was applied to calculate the absorbed radiation doses for various organs. The images showed rapid, predominantly urinary excretion of 99mTc ciprofloxacin, with low to absent brain, lung and bone marrow uptake and low liver uptake and excretion. Accordingly, imaging conditions are excellent for both the thoracic and the abdominal region, even at early time points (60 min) post injection. In none of the volunteers was the gallbladder visualised. Approximately 60% of the injected activity was recovered in urine by 24 h post injection. The highest absorbed doses were received by the urinary bladder wall, the thyroid, the upper large intestine, the lower large intestine and the uterus. The estimated mean effective dose for the adult subject, taking into account the weight factors of the ICRP60 publication, was 0.0083 mSv/MBq. The amount of 99mTc ciprofloxacin required for adequate planar and tomographic imaging results in an acceptable effective dose to the patient. PMID:11383860

  5. Glomerular filtration rate in children: validation and longitudinal use of determination from the 99mTc DTPA renogram

    SciTech Connect

    Shore, R.M.; Koff, S.A.; Hayes, J.R.; Smith, S.P.; Mentser, M.; Mahan, J.D.

    1986-09-01

    The glomerular filtration rate (GFR) was estimated from the technetium diethylenetriaminepentacetic (/sup 99m/Tc DTPA) renogram by empirically correlating the renogram and clearance of the tracer as measured by plasma disappearance kinetics. To expand the potential application of this technique from its original description, minor changes in methodology were made; a new regression was generated with 30 subjects, and that formula was then validated prospectively. For the 50 children and adolescents in the prospective series whose GFR normalized for surface area (NGFR = GFR X 1.73 m2/SA; SA, surface area) was less than 120 mL/min/1.73 m2; renal function was estimated with a mean residual error of 8.0 mL/min/1.73 m2, and a mean relative error of 11%. These results are at least as good as those in the initial report, thus validating this method in a prospective series. To examine the use of this method longitudinally, 129 examinations were reviewed in 55 subjects who had NGFR estimated from the renogram (estimated) on at least two occasions. For 28 sets of serial examinations, NGFR was also measured by the plasma disappearance of /sup 99m/Tc DTPA (measured). The true change in function for each set of serial examinations was defined as the increment for whichever method (estimation or measurement) was more stable. The mean longitudinal errors were 2.1 and 4.8 mL/min/1.73 m2 for measured and estimated NGFR, respectively. The increments in NGFR for these methods were correlated with a regression line near identity and r = .852. This indicates that a change in estimated NGFR reflects a change in measured NGFR of similar magnitude. This method can accurately estimate GFR from the /sup 99m/Tc DTPA renogram, and it can be used longitudinally to follow children with renal disorders.

  6. Use of diethyl-IDA Tc 99m clearance curves in the differentiation of biliary atresia from other forms of neonatal jaundice

    SciTech Connect

    Leonard, J.C.; Hitch, D.C.; Manion, C.V.

    1982-03-01

    A family of isotope elimination curves that reflects changes in the biodistribution of diethyl-IDA Tc 99m in neonatal cholestatic jaundice and biliary atresia is defined. Time/activity curves generated from equal areas over the heart and liver were evaluated separately and in conjunction with the scintigraphic data. Patients without scintigraphic evidence of significant hepatic uptake and with hepatic curve that resembled the cardiac curve were found to have neonatal hepatitis. Good hepatic uptake and a hepatic curve with a terminal portion that appeared to be parallel to or divergent from the cardiac curve were associated with biliary atresia. Apparently converging hepatic and cardiac curves were associated with biliary patency. Although preliminary, these results provide further documentation that diethyl-IDA Tc 99m is useful in discriminating biliary atresia from other causes of cholestatic jaundic, while reducing radiation exposure and the need for pharmacologic intervention.

  7. The use of diethyl-IDA Tc 99m clearance curves in the differentiation of biliary atresia from other forms of neonatal jaundice

    SciTech Connect

    Leonard, J.C.; Hitch, D.C.; Manion, C.V.

    1982-03-01

    A family of isotope elimination curves that reflects changes in the biodistribution of diethyl-IDA Tc 99m in neonatal cholestatic jaundice and biliary atresia is defined. Time/activity curves generated from equal areas over the heart and liver were evaluated separately and in conjunction with the scintigraphic data. Patients without scintigraphic evidence of significant hepatic uptake and with a hepatic curve that resembled the cardiac curve were found to have neonatal hepatitis. Good hepatic uptake and a hepatic curve with a terminal portion that appeared to be parallel to or divergent from the cardiac curve were associated with biliary atresia. Apparently converging hepatic and cardiac curves were associated with biliary patency. Although preliminary, these results provide further documentation that diethyl-IDA Tc 99m is useful in discriminating biliary atresia from other causes of cholestatic jaundice, while reducing radiation exposure and the need for pharmacologic intervention.

  8. 99 m Tc-sulphur-colloid and heat-denatured 99 m Tc-labelled red cell scans demonstrating a giant intrapelvic spleen in a girl after splenectomy

    Microsoft Academic Search

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

    2001-01-01

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

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

    SciTech Connect

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

    2013-04-24

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

  10. 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

  11. Investigations of 99mTc morpholino pretargeting in mice.

    PubMed

    Liu, G; Liu, C; Zhang, S; He, J; Liu, N; Gupta, S; Rusckowski, M; Hnatowich, D J

    2003-06-01

    This laboratory is exploring the use of morpholinos (MORFs), synthetic DNA analogues, for nuclear medicine applications, including pretargeting. The anti-CEA antibody MN14 was conjugated with an 18 mer MORF and with diethylenetriaminepentaacetic acid (DTPA) for 111In labelling. In a dual label pretargeting study, tumour-bearing nude mice received different doses of (MN14-DTPA-111In+MN14-MORF) followed, at various times after i.v. injection, by 0.15 microg complementary MORF (cMORF) radiolabelled with 99mTc via MAG(3). Animals were killed 3 h thereafter and tissues were counted for both radionuclides. The 99mTc-cMORF was also administered to tumour bearing mice that, 2 days previously, had received different doses of unlabelled MN14-MORF IgG or, as control, unlabelled Sandoglobulin IgG-MORF (Sandoz-MORF). Tumour uptake was higher at all time points for the labelled antibody itself versus labelled cMORF (8-10 vs 1.3-2.3%ID/g, respectively) in part due to the rapid clearance of cMORF through the kidneys. However, target to non-target ratios were superior for pretargeting at all time points and in all tissue except blood and kidneys. By pretargeting alone, these ratios were highest in all tissues for 15 microg compared to higher MN14-MORF dosages and in all cases were superior to that of the Sandoz-MORF control. The superior target to non-target ratios for pretargeting can be partially explained through calculations based on both radiolabels: after 24 h, only 0-6% of MORF on MN14 was bound by 99mTc-cMORF in liver and spleen suggesting that the antibody is sequestered in these organs and 'invisible' to labelled MORF. Fortunately, this was not the case in tumours in which 50-60% was bound. It is concluded that pretargeting using MORFs provided encouraging results in one mouse model/anti-tumour antibody system. The advantages of pretargeting in this model were evident in the superior target to non-target ratios obtained over conventional imaging. PMID:12766607

  12. Low renal uptake of 99m Tc-DMSA in patients with proximal tubular dysfunction

    Microsoft Academic Search

    W. H. J. van Lu; G. J. Ensing; D. A. Piers

    1983-01-01

    In nine patients with different types of proximal tubulopathy and a nearly normal glomerular filtration rate a low uptake of 99mTc-DMSA in the kidneys was found. The underlying mechanism seems to be an increased urinary excretion of 99mTc-DMSA. This radiopharmaceutical might be used as a marker of proximal tubular dysfunction.

  13. Unusual persistence of Tc99m MDP uptake in the incisional scar after thoracotomy

    Microsoft Academic Search

    WEI-JEN SHIH; FRANK H. DeLAND; PEGGY A. DOMSTAD; MARCUS L. DILLON

    1984-01-01

    Postoperative scar is one of the causes of extraosseous localization of Tc-99m phosphonate bone agents. Usually, an incisional scar will not be visualized in a Tc-99m phosphonate skeletal image two weeks after surgery. A case is reported with an unusually persistent localization of radiotracer in the scar of a thoracotomy seen in three consecutive bone images done beyond two weeks

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

    Microsoft Academic Search

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

    2005-01-01

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

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

    E-print Network

    Nejdl, Wolfgang

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

  16. Abnormal focal 99mTc-DMSA uptake in the lung--report of two cases.

    PubMed

    Pirayesh, Elahe; Amoui, Mahasti; Halimi Asl, Ali Asghar; Assadi, Majid

    2014-01-01

    Extrarenal uptake of 99mTc-DMSA is a rare finding, which has been described in some unusual conditions as bone metastasis, aortic aneurysm and hemangioma. The purpose of this report is to present two cases of abnormal 99mTc-DMSA uptake in the lungs, which remained unexplained even after radiologic assessment. PMID:24610651

  17. DIFFRACTION SPECTRUM OF LATTICE GAS MODELS ABOVE Tc MICHAEL BAAKE AND BERND SING

    E-print Network

    Bielefeld, University of

    DIFFRACTION SPECTRUM OF LATTICE GAS MODELS ABOVE Tc MICHAEL BAAKE AND BERND SING ABSTRACT. The diffraction spectra of lattice gas models on d with finite-range ferromagnetic two-body interactions above Tc or with certain rates of decay of the potential are considered. We show that these diffraction spectra almost

  18. 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, Brazil, the Departments of §Chemistry, ¶Biochemistry, and Medicine, University of Washington, Seattle of the Rho family. The cloned Rho protein, TcRho1, shares 40% homology with other members of the Rho family

  19. Vicarious visualization of gall bladder on Tc-99m ethylene dicysteine renal dynamic study

    PubMed Central

    Arora, Geetanjali; Damle, Nishikant A; Tripathi, Madhavi; Bal, Chandrasekhar; Kumar, Praveen

    2012-01-01

    Though the hepatobiliary excretion of Technetium-99m ethylene dicysteine (99mTc-EC) is very low and usually does not effect image interpretation on routine posterior imaging, the possibility of visualization of the gall bladder should be kept in mind while reporting the 99mTc-EC scan especially, when anterior imaging is performed as in renal transplant patients. PMID:24019659

  20. In Vitro Evaluation of Tc-99m Radiopharmaceuticals for Gastric Emptying Studies

    PubMed Central

    Ertay, Türkan; Do?an, Amet Semih; Ülker, Özden; Durak, Hatice

    2014-01-01

    Objective: Gastrointestinal motility and functional motility disorders causing either delayed or accelerated gastric emptying (GE) may result in similar symptoms including nausea, vomiting, early satiety, fullness, bloating, and abdominal discomfort or pain. Hence, it is important to evaluate patients for both rapid and delayed GE in the same test. The gold standard technique to measure GE is scintigraphy by radiolabeled test meals. The aim of this study was to test alternative Tc-99m agents to label eggs as the solid meal and compare to Tc-99m sulfur colloid (SC) for gastric emptying studies. Methods: In search of alternative agents for gastric emptying studies, we mixed and fried eggs with four different particulate compounds (Tc-99m labeled SC, tin colloid, nanocolloid and MAA), as well as with free pertechnetate and Tc-99m DTPA. We then measured the stability of these compounds in simulated gastric juice. Results: Our experiments demonstrated that in addition to Tc-99m sulfur colloid;Tc-99m MAA, Tc-99m nanocolloid and Tc-99m tin colloid also appear to make stable complexes with eggs in acidic environment. Conclusion: Therefore, these agents may be used for gastric emptying studies which could be more practical in routine conditions. Conflict of interest:None declared. PMID:24653931

  1. Equation of State for the Cooperative Transition of Triglycine Sulfate near Tc

    Microsoft Academic Search

    Julio A. Gonzalo

    1970-01-01

    Measurements of polarization versus field in the vicinity of the Curie temperature from triglycine sulfate, both below and above Tc, allow first, the determination of a number of critical exponents and second, the characterization of the ferroelectric equation of state. The relationship, below and above Tc, between the \\

  2. Localization of hemorrhage in a recurrent hemothorax using Tc-99m-sulfur colloid

    SciTech Connect

    Taillefer, R.; Essiambre, R.; Lemieux, R.

    1981-05-01

    Tc99m-sulfur colloid scintigraphy has proven clinically useful in identifying gastrointestinal hemorrhages. The authors describe a patient with recurrent hemothorax under oral anticoagulation therapy in which Tc-99m-sulfur colloid imaging was used to determine the site of bleeding.

  3. Thermal release of hidden magnetic moments in low and high T(c) type II superconductors

    Microsoft Academic Search

    David Leblanc

    1998-01-01

    Measurements of the evolution of the magnetic moment of nonideal (i.e. pinning rich) type II superconductors in stationary magnetic fields H a as a function of time at constant temperatures T < Tc or as the temperature is varied to or from Tc provide insight into the dynamics of flux lines and their interactions with the pinning sites. Three concentric

  4. 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

  5. Comparison of the Relative Renal Function Calculated with 99mTc-Diethylenetriaminepentaacetic Acid and 99mTc-Dimercaptosuccinic Acid in Children.

    PubMed

    Çelik, Tanju; Yalçin, Hülya; Günay, Emel Ceylan; Özen, Aynur; Özer, Cahit

    2014-09-01

    The aim was to compare the relative renal functions measured with technetium-99m dimercaptosuccinic acid (99mTc-DMSA) and technetium-99m diethylenetriaminepentaacetic acid (99mTc-DTPA) in children with renal diseases. Relative renal function of 128 children who applied to three hospitals from 2009 to 2011 were analyzed retrospectively. The mean value measured with 99mTc-DTPA and 99mTc-DMSA were 51.58 ± 14.95 and 51.96 ± 14.99 for the right kidney, 47.87 ± 15.27 and 47.94 ± 15.17 for the left kidney, respectively. A significant positive correlation was found between the relative renal functions (r = 0.963, P < 0.001). In Bland-Altman plots, the mean difference between two methods was 0.7 and the correlation limits were between 10.1 and-10.8. As a result, although 99mTc-DMSA is accepted as the most reliable method for the determination of relative renal function, 99mTc-DTPA can be another choice for the calculation of relative renal function without a complementary DMSA scan particularly in pediatric patients who require renogram curve and GFR calculations. PMID:25538484

  6. Usage of radiopharmaceuticals in the development of pharmaceutical drug delivery systems: validation of [99mTc]DTPA and [99mTc]ECD.

    PubMed

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

    2004-03-01

    Tablets containing drugs of different lipophilicity, ranitidine and cinarizine, and placebo were prepared and their in vitro behaviour was studied by dissolution and disintegration tests. [(99m)Tc]Diethylenetriamine-pentaacetic acid ([(99m)Tc]DTPA) and [(99m)Tc]ethyl cysteinate dimer ([(99m)Tc]ECD) were used as tracers of the process. Both of them were added to tablets during wet granulation. Dissolution and disintegration profiles were assessed at different pH values (1, 4 and 7). Radioactivity was evaluated in filtered samples and scintigraphic studies were carried out in gamma camera. Stability in dissolution media was confirmed for both tracers under these conditions. Dissolution and disintegration velocity constants were calculated. [(99m)Tc]DTPA proved to be an appropriate tracer for polar drugs such as ranitidine. Nevertheless, it was not a suitable tracer for lipophilic active drugs such as cinarizine. On the other hand, the most lipophilic tracer, [(99m)Tc]ECD, exhibited the opposite behaviour. Scintigraphic studies of the disintegration process did not show significant differences between placebos and tablets containing active drugs. As disintegration is a physical process it does not discriminate between chemical differences in tablet formulations. Both methods complement each other because the dissolution process can be followed when a suitable radiotracer is chosen according to the physicochemical characteristics of the active drug. PMID:15018995

  7. Comparison of the Relative Renal Function Calculated with 99mTc-Diethylenetriaminepentaacetic Acid and 99mTc-Dimercaptosuccinic Acid in Children

    PubMed Central

    Çelik, Tanju; Yalçin, Hülya; Günay, Emel Ceylan; Özen, Aynur; Özer, Cahit

    2014-01-01

    The aim was to compare the relative renal functions measured with technetium-99m dimercaptosuccinic acid (99mTc-DMSA) and technetium-99m diethylenetriaminepentaacetic acid (99mTc-DTPA) in children with renal diseases. Relative renal function of 128 children who applied to three hospitals from 2009 to 2011 were analyzed retrospectively. The mean value measured with 99mTc-DTPA and 99mTc-DMSA were 51.58 ± 14.95 and 51.96 ± 14.99 for the right kidney, 47.87 ± 15.27 and 47.94 ± 15.17 for the left kidney, respectively. A significant positive correlation was found between the relative renal functions (r = 0.963, P < 0.001). In Bland-Altman plots, the mean difference between two methods was 0.7 and the correlation limits were between 10.1 and-10.8. As a result, although 99mTc-DMSA is accepted as the most reliable method for the determination of relative renal function, 99mTc-DTPA can be another choice for the calculation of relative renal function without a complementary DMSA scan particularly in pediatric patients who require renogram curve and GFR calculations. PMID:25538484

  8. 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.

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

    SciTech Connect

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

    1994-12-31

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

  10. [A study of the effect of pathologic factors on the TcBM readings].

    PubMed

    Peng, D J; Zhu, Y L; Qiao, Z K; Xiong, F K; Li, Y F

    1989-03-01

    Three hundred twenty two transcutaneous bilirubin measurements (TcBM) were performed in 124 Chinese newborns with hyperbilirubinemia and jaundice in evidence. The effect of pathologic factors on the relationship between TcBM readings and total serum bilirubin (SB) levels was analyzed by multiple regression. The results of regression showed that the relationship between TcBM readings and total SB levels was affected by anemia, phototherapy, ABO and Ph hemolytic disease, and premature. Multiple stepwise regression showed that, after adjusting for each other, anemia, phototherapy and Rh hemolytic disease were the significant factors affecting the relationship between the TcBM readings and total SB levels. A practical multiple regression equation for estimation of total SB levels through TcBM readings considering the significant pathologic factors was suggested. PMID:2793147

  11. Thyroid imaging agents: a comparison of I-123 and Tc-99m pertechnetate

    SciTech Connect

    Ryo, U.Y.; Vaidya, P.V.; Schneider, A.B.; Bekerman, C.; Pinsky, S.M.

    1983-09-01

    Tc-99m pertechnetate and I-123 were used to perform thyroid scanning in 122 patients with history or clinical evidence of thyroid disease. Thyroid scans were abnormal in all patients, while thyroid palpation was abnormal in all but 19. The quality of thyroid imaging was similar with both agents in 42%, better with I-123 in 18%, and better with Tc-99m in 7%. In the remaining 33% (40 cases), there were discrepancies between Tc-99m and I-123 images. The most frequent discrepancies were ''hot'' or ''warm'' lesions on Tc-99m scans that were ''cold'' or normal on I-123 scans. Results from this study indicate that neither Tc-99m nor I-123 is always superior to the other as a thyroid imaging agent.

  12. Thyroid imaging agents: a comparison of I-123 and Tc-99m Pertechnetate

    SciTech Connect

    Ryo, U.Y.; Vaidya, P.V.; Schneider, A.B.; Bekerman, C.; Pinsky, S.M.

    1983-09-01

    Tc-99m pertechnetate and I-123 were used to perform thyroid scanning in 122 patients with history or clinical evidence of thyroid disease. Thyroid scans were abnormal in all patients, while thyroid palpation was abnormal in all but 19. The quality of thyroid imaging was similar with both agents in 42%, better with I-123 in 18%, and better with Tc-99m in 7%. In the remaining 33% (40 cases), there were discrepancies between TC-99m and I-123 images. The most frequent discrepancies were ''hot'' or ''warm'' lesions on Tc-99m scans that were ''cold'' or normal on I-123 scans. Results from this study indicate that neither TC-99m nor I-123 is always superior to the other as a thyroid imaging agent.

  13. CCMR: Kelvin Probe Microscopy for Investigation of Charge Ordering in High-Tc Superconductors

    NSDL National Science Digital Library

    Berg, Morgann

    2007-08-29

    The major hurdle that stands between high-critical-temperature (high-Tc) superconductivity as an area of pure research and the harnessing of high-Tc superconducting materials for manageable “dissipation-less” technologies is that we lack a comprehensive perception of all the mechanisms which govern high-Tc superconductivity. Controversial in nature, “charge striping” or charge ordering in superconducting transition metal oxides is arguably one of the mechanisms underlying high-Tc superconductivity. Here we introduce Kelvin Probe Force Microscopy (KPFM) and novel technologies utilizing carbon nanotubes (CNTs) as a means to resolve charge ordering in high-Tc superconducting materials. We also explore the limits of these technologies as charge-resolving tools.

  14. 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. [Department of Physics, Tsinghua University, Beijing 100084 (China); Zhu, S. J. [Department of Physics, Tsinghua University, Beijing 100084 (China); Department of Physics, Vanderbilt University, Nashville, Tennessee 37235 (United States); Hamilton, J. H.; Ramayya, A. V.; Hwang, J. K.; Liu, S. H.; Li, K. [Department of Physics, Vanderbilt University, Nashville, Tennessee 37235 (United States); Luo, Y. X. [Department of Physics, Vanderbilt University, Nashville, Tennessee 37235 (United States); Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Rasmussen, J. O.; Lee, I. Y. [Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Ma, W. C. [Department of Physics, Mississippi State University, Mississippi State, Mississippi 39762 (United States)

    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.

  15. Origin of the High Néel Temperature in SrTcO3

    NASA Astrophysics Data System (ADS)

    Mravlje, Jernej; Aichhorn, Markus; Georges, Antoine

    2012-05-01

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

  16. Origin of the high Néel temperature in SrTcO3.

    PubMed

    Mravlje, Jernej; Aichhorn, Markus; Georges, Antoine

    2012-05-11

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

  17. Bose Fluids Above Tc: Incompressible Vortex Fluids and ``Supersolidity''

    NASA Astrophysics Data System (ADS)

    Anderson, P. W.

    2008-05-01

    This Letter emphasizes that nonlinear rotational or diamagnetic susceptibility is characteristic of Bose fluids above their superfluid TC’s. For sufficiently slow rotation or, for superconductors, weak B fields, this amounts to an incompressible response to vorticity. The cause is that there are terms missing in the conventionally accepted model Hamiltonian for quantized vortices in the Bose fluid. The resulting susceptibility can account for recent observations of Chan et al. [Nature (London)NATUAS0028-0836 427, 225 (2004); 10.1038/nature02220ScienceSCIEAS0036-8075 305, 1941 (2004)10.1126/science.1101501] on solid He and Ong et al. [Europhys. Lett.EULEEJ0295-5075 72, 451 (2005)10.1209/epl/i2005-10254-4] on cuprate superconductors.

  18. 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.

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

    NASA Astrophysics Data System (ADS)

    Riofrio, L.

    2012-09-01

    Studies of the Moon, with thanks to NASA and Johnson Space Center, have quantified a large anomaly in lunar orbital evolution. The Lunar Laser Ranging Experiment (LLRE) has reported the Moon's semimajor axis increasing at 3.82±.07cm/yr, anomalously high. Tidal data indicates a rate of only 2.9±0.6 cm/yr. Historical eclipse observations indicate 2.82±.08cm/yr. Numerical simulation predicts 2.91cm/yr. LLRE's laser light differs by up to 12?. A cosmology where speed of light c is related to time t by GM=tc3 predicts that LLRE will differ by 0.935cm/yr, precisely predicting the anomaly. Observations from the Moon may shed light on "dark" mysteries of Physics.

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

    SciTech Connect

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

    1991-01-01

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

  1. 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

  2. The recovery of asteroid 2008 TC[subscript 3

    SciTech Connect

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

    2011-09-06

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

  3. [Tc1-mediated contact sensitivity reaction, its mechanism and regulation].

    PubMed

    Zemelka-Wi?cek, Magdalena; Szczepanik, Marian

    2014-01-01

    The contact hypersensitivity reaction (CHS) to haptens is a classic example of cell-mediated immune response. In the effector phase, two stages can be distinguished: an early component, that appears only 2 hours after subsequent contact with the hapten, and the late component that develops approximately 24 hours later which is mediated by TCR??+ cells. The effector lymphocytes may be CD4+ T helper 1 (Th1) cells or CD8+ T cytotoxic 1 (Tc1) cells, which depends on the employed hapten and/or mice strain. NKT lymphocytes play the crucial role in the CHS initiation, by supporting B1 cells in the antigen-specific IgM antibodies production. The development of an early component is essential for the recruitment of T effector (Teff) cells to the side of hapten deposition and for the complete expansion of inflammatory reaction. The CHS reaction is under T regulatory (Treg) cells control, both in the induction phase as well as in the effector phase. A new view of a negative regulation of the Tc1 mediated CHS response is based on the suppression induced by epicutaneous (EC) application of protein antigen. The DNP-BSA skin application, on a gauze patch, leads to a state of immunosuppression. This maneuver results in rising the population of Treg cells with TCR??+CD4+CD25+Foxp3+ phenotype. The mechanism of suppression requires direct contact between Treg cells and Teff cells and the participation of CTLA-4 molecule is also necessary. The described method of evoking immune tolerance via EC immunization may contribute to elaborate a new method of allergic contact dermatitis therapy. This is because of its effectiveness, ease of induction and non-invasive protein antigen application. PMID:25055034

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

    NASA Astrophysics Data System (ADS)

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

    2014-07-01

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

  5. 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

  6. Synopsis of French experimental and in situ research on the terrestrial and marine behavior of Tc

    SciTech Connect

    Masson, M.; Patti, F.; Colle, C.; Roucoux, P.; Grauby, A.; Saas, A. (Laboratoire de Radioecologie Marine, Cherbourg (France))

    1989-08-01

    Terrestrial environment studies have been essentially concerned with the evolution of soil deposition and soil-plant transfers. Experimentally determined coefficients of distribution in soils are low: 60-80% of Tc remains hydrosoluble during the first months. Technetium emissions resulting from microbiological activity have been quantified. Antagonistic effects on Mo and Tc retention by soils are dependent on their respective concentrations. Four areas of soil-plant transfers have been studied: (1) root absorption kinetics relative to deposition of Tc, (2) interaction of stable Mo (environmental parameter) with the transfer of Tc to plants, (3) interaction of some long-lived radioisotopes (effluent parameters) with the transfer of Tc to plants, and (4) long-term soil-plant transfer and aging of deposited material. Of aquatic systems, only the marine environment has been studied. Under anoxic conditions in the presence of reducing sediments, the distribution coefficients (Kd) were very high (10(3)). Concentration factors (CF) from water to organisms were generally very low (1 to 10); however, CF greater than 1000 have been observed for some biota such as macrophytic brown algae, worms and lobsters. Biochemical analysis showed that Tc was essentially free and partially bonded to proteins. The transfer factors between sediments and species were very low (TF less than 0.5). The biological half-time was determined in some marine organisms that had accumulated Tc from water, food or sediments; the loss is biphasic. Uptake in edible parts was low. The physiochemical form affects the accumulation and loss of Tc. Analyses have quantified 99Tc in marine fauna and biota in the English Channel in relation with releases of the reprocessing plant of La Hague. Brown algae are the best bioindicators for following 99Tc dispersion in marine ecosystems. 24 references.

  7. 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.

  8. Bromocriptine enhances the uptake of 99mTc-MIBI in patients with hepatocellular carcinoma

    PubMed Central

    Chai, Xiangting; Liu, Qiaoyu; Shao, Wenyu; Zhang, Feng; Wang, Xuehao; Wang, Hai

    2012-01-01

    99mTc-methoxyisobutyl isonitrile (MIBI) is a suitable transport substrate for the multidrug resistance gene product P-glycoprotein (P-gp) and widely used for tumor imaging. Bromocriptine has been shown to inhibit the ATPase activity and the function of P-gp. We hypothesized that bromocriptine could promote the accumulation of MIBI by inhibiting P-gp activities, a feature that can be taken advantage of for enhancing 99mTc-MIBI imaging. In the current study, we sought to investigate whether bromocriptine enhanced the uptake of 99mTc-MIBI in hepatocellular carcinoma patients. Sixty primary hepatocellular carcinoma patients received 99mTc-MIBI single photon emission computer tomgraphy (SPECT) prior to surgery. 99mTc-MIBI SPECT was performed 15 and 120 min after injection of 20 mCi 99mTc-MIBI, and early uptake, delayed uptake (L/Nd), and washout rate (L/Nwr) of 99mTc-MIBI were obtained. In addition, a second 99mTc-MIBI SPECT was performed according to the same method 48 h after bromocriptine administration. We found that, prior to bromocriptine administration, significant MIBI uptake in tumor lesions was noted in only 10 (16.7%, 10/60) patients with hepatocellular carcinoma. No significant MIBI uptake was observed in the tumor lesions of the remaining 50 (83.3%, 50/60) hepatocellular carcinoma patients. Following bromocriptine administration, all the patients without apparent MIBI uptake demonstrated significant MIBI uptake on 99mTc-MIBI SPECT (P < 0.05). Our findings indicate that bromocriptine enhances the uptake of 99mTc-MIBI in patients with hepatocellular carcinoma. PMID:23554746

  9. 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

  10. Recombinant Complement Receptor 2 Radiolabeled with [99mTc(CO)3]+ : A Potential New Radiopharmaceutical for Imaging Activated Complement

    PubMed Central

    McDonnell, James M.; Yahya, Norhakim; Thakor, David; Razavi, Reza; Smith, Richard; Sacks, Steven; Mullen, Gregory E. D.

    2011-01-01

    We describe the design and synthesis of a new Tc-99m labeled bioconjugate for imaging activated complement, based on Short Consensus Repeats 1 and 2 of Complement Receptor 2 (CR2), the binding domain for C3d. To avoid non specific modification of CR2 and the potential for modifying lysine residues critical to the CR2/C3d contact surface, we engineered a new protein, recombinant CR2 (rCR2), to include the C-terminal sequence VFPLECHHHHHH, a hexahistidine tag (for site-specific radiolabeling with [99mTc(CO)3(OH2)3]+). The protein was characterized by N-terminal sequencing, SDS-PAGE and size exclusion chromatography. To test the function of the recombinant CR2, binding to C3d was confirmed by enzyme-linked immunosorbent assay (ELISA). The function was further confirmed by binding of rCR2 to C3d+ red blood cells (RBC) which were generated by deposition of human or rat C3d and analyzed by fluorescence microscopy and flow cytometry. The affinity of rCR2 for C3d+, in presence of 150 mM NaCl, was measured using surface plasma resonance giving rise to a KD?500 nM. Radiolabeling of rCR2 or an inactive mutant of rCR2 (K41E CR2) or an unrelated protein of a similar size (C2A) with [99mTc(CO)3(OH2)3]+ at gave radiochemical yields >95%. Site-specifically radiolabeled rCR2 bound to C3d to C3d+ RBC. Binding of radiolabeled rCR2 to C3d was inhibited by anti-C3d and the radiolabeled inactive mutant K41E CR2 and C2A did not bind to C3d+ RBCs. We conclude that rCR2-Tc99m has excellent radiolabeling, stability and C3d binding characteristics and warrants in vivo evaluation as an activated complement imaging agent. PMID:21494666

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

    PubMed Central

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

    2014-01-01

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

  12. Ascophyllan purified from Ascophyllum nodosum induces Th1 and Tc1 immune responses by promoting dendritic cell maturation.

    PubMed

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

    2014-07-01

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

  13. 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

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

    SciTech Connect

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

    1989-10-04

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

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

    Microsoft Academic Search

    A. Bolsunovsky; L. Bondareva

    2008-01-01

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

  16. Impact of Boronate Capping Groups on Biological Characteristics of Novel (99m)Tc(III) Complexes [(99m)TcCl(CDO)(CDOH)2B-R] (CDOH2 = Cyclohexanedione Dioxime).

    PubMed

    Yang, Yong; Zheng, Yumin; Tomaselli, Elena; Fang, Wei; Liu, Shuang

    2015-02-18

    This study sought to explore the impact of boronate groups on the heart uptake and myocardial retention of novel (99m)Tc(III) complexes [(99m)TcCl(CDO)(CDOH)2B-R] ((99m)Tc-ISboroxime: R = isoxazol-4-yl (IS); (99m)Tc-MPboroxime: R = N-methylpyridinium (MP); (99m)Tc-PAboroxime: R = pyrazol-3-yl (PA); (99m)Tc-PYboroxime: R = pyridin-3-yl (PY); and (99m)Tc-5Uboroxime: R = uracil-5-yl (5U)). All five new (99m)Tc(III) radiotracers were prepared in high yield and high radiochemical purity (RCP = 90-98%), and they remained stable in the kit mixture for >6 h. Biodistribution and imaging (planar and SPECT) studies were carried out using Sprague-Dawley (SD) rats. Planar image quantification was performed to compare their myocardial retention and liver clearance kinetics. It was found that their heart retention and liver clearance curves were best fitted to the biexponential decay function. The initial heart uptake at 0-1 min after injection followed the general ranking order of (99m)Tc-ISboroxime (4.98 ± 1.05%ID) ? (99m)Tc-Teboroxime (4.56 ± 0.91%ID) ? (99m)Tc-PAboroxime (4.03 ± 1.23%ID) ? (99m)Tc-PYboroxime (4.07 ± 0.80%ID) > (99m)Tc-5Uboroxime (3.24 ± 0.67%ID) > (99m)Tc-MPboroxime (2.53 ± 0.65%ID). The fast-phase myocardial retention time followed the general order of (99m)Tc-PAboroxime (3.21 ± 0.29 min) > (99m)Tc-Teboroxime (1.63 ± 0.40 min) ? (99m)Tc-PYboroxime (1.57 ± 0.29 min) ? (99m)Tc-ISboroxime (1.55 ± 0.32 min) > (99m)Tc-MPboroxime (0.68 ± 0.16 min) > (99m)Tc-5Uboroxime (0.33 ± 0.11 min). (99m)Tc-PAboroxime (3.05 ± 1.10%ID/g) and (99m)Tc-ISboroxime (3.75 ± 0.68%ID/g) had the 2 min initial heart uptake very close to that of (99m)Tc-Teboroxime (3.30 ± 0.50%ID/g). However, the myocardial retention time of (99m)Tc-PAboroxime was significantly longer than that of (99m)Tc-ISboroxime and (99m)Tc-Teboroxime. Even though the best time window is 0-5 min for SPECT image acquisition, high quality SPECT images could be obtained during the first 30 min postinjection of (99m)Tc-PAboroxime in SD rats. This statement was supported by the SPECT/CT studies in normal pigs. On the basis of results from this study, it was concluded that boronate groups had significant impact on the heart uptake, myocardial retention, and liver clearance kinetics of (99m)Tc(III) complexes [(99m)TcCl(CDO)(CDOH)2B-R]. The combination of high initial heart uptake with longer myocardial retention makes it possible to image the heart with (99m)Tc-PAboroxime during the first 30 min using both standard and specialized cardiac SPECT cameras. PMID:25585053

  17. 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. (Mount Sinai School of Medicine, New York, NY (USA))

    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.

  18. GENERATION. Universitet,

    E-print Network

    Kessler, Christoph

    INTEGRATED CODE GENERATION. Page 1 C. Kessler, IDA, Link Ë? opings Universitet, 2002. INTEGRATED generation approaches OPTIMIST INTEGRATED CODE GENERATION. Page 2 C. Kessler, IDA, Link Ë? opings Universitet. Page 3 C. Kessler, IDA, Link Ë? opings Universitet, 2002. INSTRUCTION SELECTION naive instruction

  19. Chemistry and biology of Tc-99m renal function radiopharmaceuticals. Final report, May 1, 1982-January 15, 1983

    SciTech Connect

    Not Available

    1983-01-01

    Progress is reported on research conducted during the period May 1, 1982 to January 15, 1983. The chemistry and biology of two possible renal function radiopharmaceuticals, Tc-99m N, N'-bis (mercaptoacetyl)-2,3-diamino-propanoate (Tc-99m CO/sub 2/DADS, 1(X=OH)) and the Tc-99m complex of penicillamine. (ACR)

  20. [99mTc(CO)3]+ and [99mTcO2]+ radiolabeled cyclic melanotropin peptides for melanoma SPECT imaging.

    PubMed

    Zhang, Xiuli; Teixeira, Vania; Porcal, Williams; Cabral, Pablo; Gambini, Juan-Pablo; Fernandez, Marcelo; Gallazzi, Fabio; Quinn, Thomas P

    2014-01-01

    The melanoma targeting peptides (Ala-triazol)Ac-Re(Arg(11))CCMSH and N4-CO-Re(Arg(11))CCMSH were radiolabeled with [(99m)Tc(CO)3](+) and [(99m)TcO2](+), respectively, and examined for in vitro cell binding, in vivo biodistribution and imaging properties. The (Ala-triazol)Ac-Re(Arg(11))CCMSH and N4-CO-Re(Arg(11))CCMSH were synthesized as protected peptides on resin followed by rhenium cyclization with [(C6H5)3P]2ReOCl3 in DMF. The peptides were labeled with (99m)Tc and examined for radiochemical stability and melanoma cell binding. In vivo biodistribution and SPECT/CT imaging studies were performed in B16/F1 melanoma tumor bearing C57 mice. (99m)Tc(CO)3-(Ala-Triazol)Ac- Re(Arg(11))CCMSH and (99m)TcO2-N4-CO-Re(Arg(11))CCMSH were stable and internalized in B16/F1 melanoma cells upon binding. In vivo biodistribution studies revealed that tumor uptake of (99m)Tc(CO)3-(Ala-Triazol)Ac-Re(Arg(11))CCMSH was 6.08±1.06% ID/g and 7.05±1.48% ID/g at 2 h and 4 h post injection, respectively. Tumor uptake of (99m)TcO2-N4-CORe(Arg(11))CCMSH was 7.54±1.82% ID/g and 2.28±0.22% ID/g at 1 h and 2 h post injection, respectively. SPECT/CT imaging studies showed that tumor selective uptake of the radiolabeled peptides, which was confirmed by competitive blocking studies. PMID:25022516

  1. 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.

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

    PubMed Central

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

    1994-01-01

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

  3. Mapping lymph nodes in cancer management – role of 99mTc-tilmanocept injection

    PubMed Central

    Tausch, Christoph; Baege, Astrid; Rageth, Christoph

    2014-01-01

    Two decades ago, lymphatic mapping of sentinel lymph nodes (SLN) was introduced into surgical cancer management and was termed sentinel node navigated surgery. Although this technique is now routinely performed in the management of breast cancer and malignant melanoma, it is still under investigation for use in other cancers. The radioisotope technetium (99mTc) and vital blue dyes are among the most widely used enhancers for SLN mapping, although near-infrared fluorescence imaging of indocyanine green is also becoming more commonly used. 99mTc-tilmanocept is a new synthetic radioisotope with a relatively small molecular size that was specifically developed for lymphatic mapping. Because of its small size, 99mTc-tilmanocept quickly migrates from its site of injection and rapidly accumulates in the SLN. The mannose moieties of 99mTc-tilmanosept facilitate its binding to mannose receptors (CD206) expressed in reticuloendothelial cells of the SLN. This binding prevents transit to second-echelon lymph nodes. In Phase III trials of breast cancer and malignant melanoma, and Phase II trials of other malignancies, 99mTc-tilmanocept had superior identification rates and sensitivity compared with blue dye. Trials comparing 99mTc-tilmanocept with other 99mTc-based agents are required before it can be routinely used in clinical settings. PMID:25028560

  4. Transposon Tc1 of the nematode Caenorhabditis elegans jumps in human cells.

    PubMed Central

    Schouten, G J; van Luenen, H G; Verra, N C; Valerio, D; Plasterk, R H

    1998-01-01

    The transposon Tc1 of the nematode Caenorhabditis elegans is a member of the widespread family of Tc1/mariner transposons. The distribution pattern of virtually identical transposons among insect species that diverged 200 million years ago suggested horizontal transfer of the elements between species. Thishypothesis gained experimental support when it was shown that Tc1 and later also mariner transposons could be made to jump in vitro , with their transposase as the only protein required. Later it was shown that mariner transposons from one fruit fly species can jump in other fruit fly species and in a protozoan and, recently, that a Tc1-like transposon from the nematode jumps in fish cells and that a fish Tc1-like transposon jumps in human cells. Here we show that the Tc1 element from the nematode jumps in human cells. This provides further support for the horizontal spread hypothesis. Furthermore, it suggests that Tc1 can be used as vehicle for DNA integration in human gene therapy. PMID:9611249

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

    SciTech Connect

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

    1984-08-01

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

  6. Optical imaging of Tc-99m-based tracers: in vitro and in vivo results

    NASA Astrophysics Data System (ADS)

    Spinelli, Antonello E.; Meo, Sergio Lo; Calandrino, Riccardo; Sbarbati, Andrea; Boschi, Federico

    2011-11-01

    It has been recently shown that optical imaging (OI) methods can be used to image the in vivo biodistribution of several radiopharmaceuticals labeled with beta or alpha emitters. In this work particular attention has been focused on investigating the weaker optical signal induced by an almost pure gamma emitter like Tc-99m. Visible light emission measurements of a water solution containing Tc-99m were performed using a small animal OI system. A sequence of images was acquired for 24 h in order to study the decay of the luminescence signal. The difference between the luminescence decay half life and well-known Tc-99m half life was equal to 1%. in vivo imaging was performed by injecting one control nude mice with Tc-99m-MDP. Optical images obtained with equipment designed for bioluminescence imaging showed that a visible light emission was distinguishable and correctly localized in the bladder region where a higher concentration of Tc-99m-MDP was expected. The bladder to background ratio was always greater than 1. We conclude that the experimental data presented in this paper show that it is possible to detect in vivo luminescence optical photons induced by Tc-99m. This is important especially considering the large number of Tc-99m-based radiopharmaceutical currently available.

  7. Lung 99mTc-MIBI scintigraphy: impact on diagnosis of solitary pulmonary nodule

    PubMed Central

    Nikoletic, Katarina; Lucic, Silvija; Peter, Andrea; Kolarov, Violeta; Zeravica, Radmila; Srbovan, Dolores

    2011-01-01

    Most of today available non-invasive procedures cannot clearly determinate between benign and malignant solitary pulmonary nodules (SPN). The purpose of the study was to assess the possibility of using 99mTc labeled hexakis-2-methoxyisobutylisonitrile (99mTc-MIBI) to differentiate benign from malignant SPN. Sixty patients were included in the study if the CT scan showed indeterminate SPN. Prior to definitive diagnosis 99mTc-MIBI single photon emission computerized tomography (SPECT) was performed: early scan 10 minutes and delayed 60-120 minutes after the intravenous injection of 740 MBq 99mTc-MIBI using dual-headed Gamma camera. The results were considered positive if there was an increased accumulation of the radiopharmaceutical in the area of the lung corresponding to the location of the lesion. The mean nodule size ± SD measured on CT scan was 2.96 cm. Lung cancer was diagnosed in 30/60 patients (14 squamocellular, 10 adenocarcinoma, 3 large-cell and 3 microcellular lung carcinomas). Of the 30 patients with malignant lesions, 27 patients (90%) had positive 99mTc-MIBI scan results by qualitative assessment. Among benign lesions, 23/30 (76.7%) were negative on 99mTc-MIBI scan. The size and PH report of SPN is statistically significantly influencing on 99mTc-MIBI accumulation in the SPN (p<0.01). The sensitivity, specificity, accuracy, positive and negative predictive value were 90%, 76.6%, 79.4%, 88.5% and 83.3% respectively. 99mTc-MIBI SPECT is an inexpensive non-invasive diagnostic procedure which might be useful diagnostic modality in the evaluation of SPN. Easy availability and low cost makes 99mTc-MIBI SPECT an attractive method in evaluating SPN. PMID:21875420

  8. Asialoglycoprotein-receptor-targeted hepatocyte imaging using 99mTc galactosylated chitosan.

    PubMed

    Kim, Eun-Mi; Jeong, Hwan-Jeong; Kim, Se-Lim; Sohn, Myung-Hee; Nah, Jae-Woon; Bom, Hee-Seung; Park, In-Kyu; Cho, Chong-Su

    2006-05-01

    This study investigated the usefulness of 99mTc hydrazinonicotinamide-galactosylated chitosan (HGC) in hepatocyte imaging. HGC was obtained by coupling the galactose moiety of both lactobionic acid and succinimidyl 6-hydrazinonicotinate hydrochloride (succinimidyl HYNIC). The coupled product was then radiolabeled with 99mTc using stannous chloride and tricine as reducing agent and coligand, respectively. Labeling efficiency was >90% both in room temperature and in serum up to 24 h after injection. The hepatic uptake properties of 99mTc HGC were studied in Balb/C mice. 99mTc HGC and 99mTc hydrazinonicotinamide chitosan (HC) were intravenously injected into mice, with receptor binding identified by coinjection with 9 and 14 mg of free galactose. Images were acquired with a gamma-camera. After injection via the tail vein of the mice, 99mTc HGC showed high selectivity for the liver, while 99mTc HC without a galactose group showed low liver uptake. In addition, the hepatic uptake of 99mTc HGC was blocked by coinjection of free galactose. Tissue distribution was determined at three different times (10, 60 and 120 min). The liver accumulated 13.16+/-2.72%, 16.11+/-5.70% and 16.55+/-2.28% of the injected dose per gram at 10, 60 and 120 min after injection, respectively. 99mTc HGC showed specific and rapid targeting of hepatocytes. It is a promising receptor-specific radiopharmaceutical with potential applications in liver imaging for the evaluation of hepatocytic function. PMID:16720245

  9. 99mTc(CO)3(NTA): A 99mTc Renal Tracer with Pharmacokinetic Properties Comparable to Those of 131I-OIH in Healthy Volunteers

    PubMed Central

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

    2010-01-01

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

  10. 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.

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

    PubMed Central

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

    2014-01-01

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

  12. 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

  13. 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).

  14. 99mTc-DMSA scanning to diagnose pyelonephritic scarring in children

    SciTech Connect

    Kogan, B.A.; Kay, R.; Wasnick, R.J.; Carty, H.

    1983-06-01

    99mTechnetium-labeled dimercaptosuccinic acid (99mTc-DMSA) scanning provides superior quality images of renal parenchymal detail, which makes it highly sensitive for the diagnosis of pyelonephritic scarring. Unlike most other imaging techniques, radionuclide scanning is not affected by bowel gas or bony structures overlying the kidneys. This makes it particularly useful in children. Furthermore, renal scarring can be demonstrated by 99mTc-DMSA even before the classic gross anatomic and radiologic changes are present. The use of 99mTc-DMSA scanning in over 300 children has demonstrated its benefits and advantages over standard radiographic techniques.

  15. Growth plate uptake of tc-99m-phytate on lymphoscintigraphy images.

    PubMed

    Ravari, Hasan; Sadri, Kayvan; Sadeghi, Ramin

    2015-03-01

    We report two pediatric cases with the history of lower extremity edema who were referred to the nuclear medicine department for lower limb lymphoscintigraphy as lymphedema workup. Subcutaneous injection of Tc-99m phytate in the interdigital webs was used for both patients, followed by early and delayed whole body lymphoscintigraphy imaging. Images of both patients showed Tc-99m phytate accumulation in the growth plates of the lower limbs. This biodistribution could interfere with popliteal lymph node visualization and should always be taken into account in lymphoscintigraphy of pediatric patients. We also review the medical literature regarding biodistribution Tc-99m phytate after interstitial injections. PMID:24837803

  16. 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

  17. Conveniently prepared Tc-99m resin for semisolid gastric emptying studies

    SciTech Connect

    Wirth, N. (Univ. of Michigan, Ann Arbor); Shapiro, B.; Nakajo, M.; Coffey, J.L.; Eckhauser, F.; Owyang, C.

    1983-06-01

    A polystyrene resin, suitable for semi-solid gastric emptying studies, was rapidly (<20 min) and coveniently prepared using commercially available reagents. Using the outlined procedure, Chelex-100 resin bound Tc-99m with greater than 98% labeling efficiency. The resulting Tc-99m Chelex-100 resin demonstrated excellent in vitro and in vivo stability. The clinical application of Tc-99m Chelex-100 resin, mixed with oatmeal, was tested in normal subjects and in various patient groups, including diabetic autonomic neuropathy, pyloric obstruction, postoperative dumping syndrome, and morbidly obese patients before and after gastroplasty.

  18. A conveniently prepared Tc-99m resin for semisolid gastric emptying studies

    SciTech Connect

    Wirth, N.; Swanson, D.; Shapiro, B.; Nakajo, M.; Coffey, J.L.; Eckhauser, F.; Owyang, C.

    1983-06-01

    A polystyrene resin, suitable for semi-solid gastric emptying studies, was rapidly (less than 20 min) and conveniently prepared using commercially available reagents. Using the outlined procedure, Chelex-100 resin bound Tc-99m with greater than 98% labeling efficiency. The resulting Tc-99m Chelex-100 resin demonstrated excellent in vitro and in vivo stability. The clinical application of Tc-99m Chelex-100 resin, mixed with oatmeal, was tested in normal subjects and in various patient groups, including diabetic autonomic neuropathy, pyloric obstruction, postoperative dumping syndrome, and morbidly obese patients before and after gastroplasty.

  19. /sup 99m/Tc-aprotinin: A new tracer for kidney morphology and function

    SciTech Connect

    Bianchi, C.; Donadio, C.; Tramonti, G.; Lorusso, P.; Bellitto, L.; Lunghi, F.

    1984-01-01

    Aprotinin (Ap), a low molecular weight polyeptide (6500 dalton), is a protease inhibitor which is electively and stably accumulated in the kidney. In 112 adult patients, with either uni- or bilateral renal disease with different degrees of renal impairment (from normal GFR to advanced renal failure), renal scans were performed by means of Ap labelled with /sup 99m/Tc. Highly satisfactory renal scans were obtained in all patients. In 20 patients with renal failure (serum creatinine 1.8 - 8.5 mg/dl, mean 4.7) a comparison was made of the renal scans obtained with /sup 99m/Tc-Ap and with /sup 99m/Tc-DMSA. /sup 99m/Tc-Ap was slightly better than /sup 99m/Tc-DMSA, especially in patients with far advanced renal failure. Some aspects of the pharmacokinetics of /sup 99m/Tc-Ap were studied in 72 cases. In 22 of these patients plasma clearance of /sup 99m/Tc-Ap was determined by the single injection method using a two-compartment model. In patients with GFR>90 ml/min plasma cl of /sup 99m/Tc-Ap was 67.6 +- 8.4 SD ml/min. A good correlation was observed between plasma clearance of /sup 99m/Tc-Ap and GFR (r = 0.74). After i.v. injection /sup 99m/Tc-Ap was stably fixed by the kidney. Renal radioactivity remained stable between the 2nd and the 8th hour after the injection. Urinary excretion of radioactivity measured in 35 patients in the first and in the second 2-hour interval after i.v. injection of /sup 99m/Tc-Ap was negligible in all patients (2.7 +- 1.5 SD percent of the dose in the fist 2 hours; 2.8 +- 1.4 SD between the 2nd and the 4th hour). Conclusions. /sup 99m/Tc-Ap is an excellent agent for renal imaging. It also seems promising for renal function studies.

  20. Experimental Study of [99mTc(PNP5) (DBODC)]+ as a New Myocardial Perfusion Imaging Agent

    Microsoft Academic Search

    Wan-Chun Zhang; Wei Fang; Bin Li; Xue-Bin Wang; Zuo-Xiang He

    2009-01-01

    Objectives: This study was aimed to compare the properties of [99mTc(PNP5)(DBODC)]+ with 99mTc-MIBI in normal swine and in canine models of myocardial ischemia. Methods: Seven anesthetized swine were injected intravenously with [99mTc(PNP5)(DBODC)]+. Serial planar images were acquired meanwhile. Twelve adult dogs were studied. A critical stenosis of left anterior descending artery was produced. [99mTc(PNP5)(DBODC)]+ or 99mTc-MIBI (randomly) was injected intravenously

  1. 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

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

    PubMed Central

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

    2014-01-01

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

  3. Wind Generator

    NSDL National Science Digital Library

    The Concord Consortium

    2012-05-21

    Windmills have been used for hundreds of years to collect energy from the wind in order to pump water, grind grain, and more recently generate electricity. There are many possible designs for the blades of a wind generator and engineers are always trying new ones. Design and test your own wind generator, then try to improve it by running a small electric motor connected to a voltage sensor.

  4. Distributed generation

    SciTech Connect

    Ness, E.

    1999-09-02

    Distributed generation, locating electricity generators close to the point of consumption, provides some unique benefits to power companies and customers that are not available from centralized electricity generation. Photovoltaic (PV) technology is well suited to distributed applications and can, especially in concert with other distributed resources, provide a very close match to the customer demand for electricity, at a significantly lower cost than the alternatives. In addition to augmenting power from central-station generating plants, incorporating PV systems enables electric utilities to optimize the utilization of existing transmission and distribution.

  5. (99m)Tc-YIGSR as a receptor tracer in imaging the Ehrlich ascites tumor-bearing mice as compared with (99m)Tc-MIBI.

    PubMed

    Hu, Jia; Qin, Guangming; Zhang, Yongxue; An, Rui; Lan, Xiaoli

    2007-08-01

    The validity of (99m)Tc-YIGSR, a novel receptor radio-tracer, in imaging the Ehrlich ascites tumor was evaluated. YIGSR, a pentapeptide of laminin, was labeled with (99m)Tc by using a bifunctional chelator S-Acetly-NH(3)-MAG(3). The MIBI was labeled with (99m)Tc by following the kit instruction. The mice of tumor group were intravenously injected 1-2 mCi of (99m)Tc-YIGSR or (99m)Tc-MIBI via caudal vein, immobilized and imaged under a Gamma camera. The same procedure was performed in mice of blockade group, in which the unlabeled YIGSR was previously injected to block the receptor-recognition sites, and inflammation group serving as control. The reverse-phase Sep-Pak C(18) chromatogram was found to have an essentially complete conjugation between YIGSR and S-Acetly-NH(3)-MAG(3). The conjugated YIGSR could be radio-labeled successfully with (99m)Tc at room temperature and neutral pH, with a radio-labeling yield of 62%. Without the chelator S-Acetly-NH(3)-MAG(3), the YIGSR was labeled with (99m)Tc at an efficiency of 4%. The imagological study revealed obvious tumor accumulation of (99m)Tc-YIGSR 15 min after the injection, and the uptake peaked after 3 h with a tumor-to-muscle ratio (T/M) of 11.36. The radio-tracer was slowly cleared up and resulted in a T/M of 3.01 at the 8th h after the injection. As for blocked group, the tumor uptake of radiotracer was significantly lower, with the highest T/M being 4.61 after 3 h and 0.89 after 8 h. The T/M was 3.72 at the 3rd h and 1.29 at the 8th h after the (99m)Tc-YIGSR injection in the inflammatory group. The T/M was significantly higher in tumor group than in inflammatory group or control group (P<0.001). In the 99mTc-MIBI group, the T/M was 1.40 at the 3rd h and 0.55 at the 8th h after the injection, which showed a significant difference as compared with (99m)Tc-YIGSR (P<0.001). It is concluded that YIGSR can be successfully radiolabelled by using S-Acetly-NH(3)-MAG(3). (99m)Tc-YIGSR has many advantages in tumor imaging, such as quick and clear visualization, high sensitivity and specificity, and satisfactory target/non-target ratio (N/NT). It promises to be tumor radio-tracer. PMID:17828515

  6. Single-crystal EPR and 15N powder ENDOR studies of [(C 4H 9) 4N][Tc VINBr 4/Tc VOBr 4

    NASA Astrophysics Data System (ADS)

    Köhler, K.; Kirmse, R.; Böttcher, R.; Abram, U.

    1992-03-01

    Single-crystal EPR and 15N powder ENDOR studies of tetra-n-butylammoniumtetrabromonitrido-technetate(VI), (Bu 4N)[TcNBr 4], diamagnetically diluted by the isostructural oxotechnetate(V) complex are reported. The EPR spectra are typical of an ion with 4d 1 configuration and confirm an "in-plane" ?-type molecular orbital of the unpaired electron (C 4v, symmetry). At low temperatures very complex 99Tc and 79,81Br hyperfine patterns are observed in the single-crystal EPR spectra. The 15N hyperfine tensor has been derived from powder ENDOR measurements. Hyperfine and ligand hyperfine data are analyzed to evaluate the electron spin delocalization and compared to those obtained from molecular orbital calculations (EHMO and NDDO). The nitrogen coupling is mainly determined by spin polarization. The fraction of the unpaired electron that is delocalized over ligand orbitals is larger in the bromo than in the corresponding chloro complex [TcNCl 4] -.

  7. False Negative 99mTc-Hydroxymethane Diphosphonate Three-phase Bone Scintigraphy and 99mTc-besilesomab Scan in Detecting Tibia Osteomyelitis Concomitant with Necrotizing Fasciitis

    PubMed Central

    Tan, Teik Hin; Lee, Boon Nang

    2014-01-01

    We described a case of 51-year-old female patient presented with a right calf necrotising fasciitis (NF) where osteomyelitis (OM) was suspected. 99mTc-hydroxymethane diphosphonate three-phase bone scintigraphy and 99mTc-besilosomab scan failed to demonstrate classical features of OM. The final diagnosis was only made by isolating Acinetobacter sp. in both intra-operative bone and tissue cultures from below-knee amputation. As conclusions, the detection of lower limb OM by 99mTc-besilosomab scan is not easy when there is concurrence overlying NF. The unusual three-phase bone scan finding of pericortical accumulation of tracer as an early sign of OM is highlighted in this case. PMID:25538491

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

    NASA Astrophysics Data System (ADS)

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

    2014-12-01

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

  9. Superconductivity Fluctuation and Magnetoresistance of High-Tc Superconductors.

    NASA Astrophysics Data System (ADS)

    Semba, Kouichi; Matsuda, Azusa

    1996-03-01

    We have reanalysed the normal state magnetoresistance (MR) of 90K- and Zn-doped-YBCO high-Tc superconductors (HTS) by the following two models: (i) superconducting fluctuation of Maki-Thompson process (MT-paraconductivity), (ii) normal state MR in the Boltzmann transport theory. While model (i) encounters severe difficulties, Hall angles obtained by model (ii) agree well with Hall measurements. This demonstrates the appropriateness of model (ii). We had shown that Aslamazov-Larkin (AL) paraconductivity is enough to explain longitudinal MR of 90K-YBCO(K. Semba, T. Ishii, and A. Matsuda, Phys. Rev. Lett. 67, 769 (1991); 67, 2114(E) (1991). ) . As stated above, we show that the AL-fluctuation is also enough to explain orbital MR of 90K- and Zn-doped-YBCO. The MR, which we had assigned to the MT-Orbital paraconductivity, is more naturally understood as the normal state orbital MR (J. M. Harris, Y. F. Yan, P. Malt, N. P. Ong, P. W. Anderson, T. Kimura, and K. Kitazawa, Phys. Rev. Lett. 75, 1391 (1995).). We conclude that MT-fluctuation is vanishingly small in these HTS.

  10. 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

  11. Imaging bacterial infection with 99mTc-ciprofloxacin (Infecton)

    PubMed Central

    Britton, K E; Wareham, D W; Das, S S; Solanki, K K; Amaral, H; Bhatnagar, A; Katamihardja, A H S; Malamitsi, J; Moustafa, H M; Soroa, V E; Sundram, F X; Padhy, A K

    2002-01-01

    Aims: The diagnosis of deep seated bacterial infections, such as intra-abdominal abscesses, endocarditis, and osteomyelitis, can be difficult and delayed, thereby compromising effective treatment. This study assessed the efficacy of a new radioimaging agent, Tc-99m ciprofloxacin (Infecton), in accurately detecting sites of bacterial infection. Methods: Eight hundred and seventy nine patients with suspected bacterial infection underwent Infecton imaging and microbiological evaluation. The sensitivity and specificity of Infecton in detecting sites of bacterial infection were determined with respect to Centres of Disease Control, World Health Organisation, and Dukes’s criteria. Results: Five hundred and seventy four positive and 295 negative images were produced. These included 528 true positives, 46 false positives, 205 true negatives and 90 false negatives, giving an overall sensitivity of 85.4% and a specificity of 81.7% for detecting infective foci. Sensitivity was higher (87.6%) in microbiologically confirmed infections. Conclusions: Infecton is a sensitive technique, which aids in the earlier detection and treatment of a wide variety of deep seated bacterial infections. The ability to localise infective foci accurately is also important for surgical intervention, such as drainage of abscesses. In addition, serial imaging with Infecton might be useful in monitoring clinical response and optimising the duration of antimicrobial treatment. PMID:12401818

  12. GM=tc^3 Cosmology and the Moon

    NASA Astrophysics Data System (ADS)

    Riofrio, Louise

    2010-10-01

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

  13. 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.

  14. Dynamic resistance of a high-Tc superconducting flux pump

    NASA Astrophysics Data System (ADS)

    Jiang, Zhenan; Hamilton, K.; Amemiya, Naoyuki; Badcock, R. A.; Bumby, C. W.

    2014-09-01

    Superconducting flux pumps enable large currents to be injected into a superconducting circuit, without the requirement for thermally conducting current leads which bridge between the cryogenic environment and room temperature. In this work, we have built and studied a mechanically rotating flux pump which employs a coated conductor high-Tc superconducting (HTS) stator. This flux pump has been used to excite an HTS double pancake coil at 77 K. Operation of the flux pump causes the current within the superconducting circuit to increase over time, before saturating at a limiting value. Interestingly, the superconducting flux pump is found to possess an effective internal resistance, Reff, which varies linearly with frequency, and is two orders of magnitude larger than the measured series resistance of the soldered contacts within the circuit. This internal resistance sets a limit for the maximum achievable output current from the flux pump, which is independent of the operating frequency. We attribute this effect to dynamic resistance within the superconducting stator wire which is caused by the interaction between the DC transport current and the imposed alternating magnetic field. We provide an analytical expression describing the output characteristics of our rotating flux pump in the high frequency limit, and demonstrate that it describes the time-dependent behavior of our experimental circuit. Dynamic resistance is highlighted as a generic issue that must be considered when optimizing the design of an HTS flux pump.

  15. Mono- and dicationic Re(I)/(99m)Tc(I) tricarbonyl complexes for the targeting of energized mitochondria.

    PubMed

    Moura, Carolina; Mendes, Filipa; Gano, Lurdes; Santos, Isabel; Paulo, António

    2013-06-01

    The enhanced negative mitochondrial membrane potential of tumor cells can increase the cell accumulation of triphenylphosphonium (TPP) derivatives, which prompted us to investigate TPP-containing Re(I)/(99m)Tc organometallic compounds as probes for in vivo targeting of energized mitochondria. Novel compounds (Re1-Re4/Tc1-Tc4) were obtained with bifunctional chelators of the pyrazole-diamine (N,N,N-donors) and pyrazole-aminocarboxylic (N,N,O-donors) type, functionalized with TPP pharmacophores that have been introduced at the central amine of the chelators using different spacers. In this way, dicationic (Re1-Re2, Tc1-Tc2) and monocationic (Re3-Re4, Tc3-Tc4) complexes with variable lipophilicity were synthesized. The (99m)Tc complexes (Tc1-Tc4) are highly stable under physiological conditions and their chemical identification was done by HPLC comparison with the Re congeners (Re1-Re4), which were fully characterized by common analytical techniques (electrospray ionization mass spectrometry (ESI-MS), IR, multinuclear NMR). The in vitro biological evaluation of Tc1-Tc4 was performed in a panel of human tumor cell lines (PC-3, MCF-7 and H69), including cell lines overexpressing P-glycoprotein (MCF-7/MDR1 and H69/Lx4), and in isolated mitochondria. All the tested complexes showed a low to moderate cellular and mitochondrial uptake and did not undergo significant P-glycoprotein (Pgp)-mediated efflux processes. In particular, the dication Tc2 and the monocation Tc4 presented the highest cellular and mitochondrial uptake. Their cellular uptake was shown to depend on the mitochondrial (??m) and plasma membrane (??p) potentials. Altogether, the biological properties of these compounds suggest that they might be relevant for the design of radioactive metalloprobes for in vivo targeting of mitochondria. PMID:23507077

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

    PubMed

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

    2009-12-01

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

  17. Reduction of pertechnetate [Tc(VII)] by aqueous Fe(II) and the nature of solid phase redox products

    NASA Astrophysics Data System (ADS)

    Zachara, John M.; Heald, Steve M.; Jeon, Byong-Hun; Kukkadapu, Ravi K.; Liu, Chongxuan; McKinley, James P.; Dohnalkova, Alice C.; Moore, Dean A.

    2007-05-01

    The subsurface behaviour of 99Tc, a contaminant resulting from nuclear fuels reprocessing, is dependent on its valence (e.g., IV or VII). Abiotic reduction of soluble Tc(VII) by Fe(II) (aq) in pH 6-8 solutions was investigated under strictly anoxic conditions using an oxygen trap (<7.5 × 10 -9 atm O 2). The reduction kinetics were strongly pH dependent. Complete and rapid reduction of Tc(VII) to a precipitated Fe/Tc(IV) form was observed when 11 ?mol/L of Tc(VII) was reacted with 0.4 mmol/L Fe(II) at pH 7.0 and 8.0, while no significant reduction was observed over 1 month at pH 6.0. Experiments conducted at pH 7.0 with Fe(II) (aq) = 0.05-0.8 mmol/L further revealed that Tc(VII) reduction was a combination of homogeneous and heterogeneous reaction. Heterogeneous reduction predominated after approximately 0.01 mmol/L of Fe(II) was oxidized. The heterogeneous reaction was more rapid, and was catalyzed by Fe(II) that adsorbed to the Fe/Tc(IV) redox product. Wet chemical and Fe-X-ray absorption near edge spectroscopy measurements (XANES) showed that Fe(II) and Fe(III) were present in the Fe/Tc(IV) redox products after reaction termination. 57Fe-Mössbauer, extended X-ray adsorption fine structure (EXAFS), and transmission electron microscopy (TEM) measurements revealed that the Fe/Tc(IV) solid phase was poorly ordered and dominated by Fe(II)-containing ferrihydrite with minor magnetite. Tc(IV) exhibited homogeneous spatial distribution within the precipitates. According to Tc-EXAFS measurements and structural modeling, its molecular environment was consistent with an octahedral Tc(IV) dimer bound in bidentate edge-sharing mode to octahedral Fe(III) associated with surface or vacancy sites in ferrihydrite. The precipitate maintained Tc(IV) aq concentrations that were slightly below those in equilibrium with amorphous Tc(IV)O 2· nH 2O (s). The oxidation rate of sorbed Tc(IV) in the Fe/Tc precipitate was considerably slower than Tc(IV)O 2· nH 2O (s) as a result of its intraparticle/intragrain residence. Precipitates of this nature may form in anoxic sediments or groundwaters, and the intraparticle residence of sorbed/precipitated Tc(IV) may limit 99Tc remobilization upon the return of oxidizing conditions.

  18. 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.

  19. 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.

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

    PubMed Central

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

    2009-01-01

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

  1. Ran/TC4: a small nuclear GTP-binding protein that regulates DNA synthesis

    PubMed Central

    1993-01-01

    Ran/TC4, first identified as a well-conserved gene distantly related to H-RAS, encodes a protein which has recently been shown in yeast and mammalian systems to interact with RCC1, a protein whose function is required for the normal coupling of the completion of DNA synthesis and the initiation of mitosis. Here, we present data indicating that the nuclear localization of Ran/TC4 requires the presence of RCC1. Transient expression of a Ran/TC4 protein with mutations expected to perturb GTP hydrolysis disrupts host cell DNA synthesis. These results suggest that Ran/TC4 and RCC1 are components of a GTPase switch that monitors the progress of DNA synthesis and couples the completion of DNA synthesis to the onset of mitosis. PMID:8421051

  2. Preparation and evaluation of (99m)Tc-DMSA lyophilized kit for renal imaging.

    PubMed

    Jan, Syed Umer; Abbass, Hafiz Ghulam

    2013-05-01

    Dimercaptosuccinic acid (DMSA) has been evaluated and used with technetium 99m ((99m)Tc) in imaging of kidneys. DMSA lyophilized kits were prepared and radiolabelled with (99m)Tc. Paper and thin-layer chromatography have been employed using various eluent systems for the radiochemical analysis, percentage labeling and binding capacity of (99m)Tc-DMSA. Female albino rabbits were used for this study. Biological data obtained after intravenous injection of radiolabelled DMSA to female albino rabbits revealed 32.42% uptake and long retention time in the kidneys. On the basis of animal biodistribution data, it is suggested that DMSA when labeled with (99m)Tc is useful complex for renal imaging and can be successfully applied as a diagnostic tool in nuclear medicine. Clinical biodistribution and radiation dosimetry studies are planned in future. PMID:23625428

  3. 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.

  4. 75 FR 32458 - TC Ravenswood, LLC v. New York Independent System Operator, Inc.; Notice of Complaint

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-08

    ...against New York Independent System Operator, Inc. (NYISO) (Respondent), requesting FERC order the NYISO to reimburse TC Ravenswood, LLC, as required by section 4.1.7a of the NYISO Services Tariff for the variable costs, inclusive...

  5. Detection of Meckel's diverticulum in an infant by Tc-99m-sulfur colloid scintigraphy

    SciTech Connect

    Ryan, J.W.; Sepahdari, S.

    1981-05-01

    Active lower intestinal bleeding from a Meckel's diverticulum in an infant was detected with Tc-99m-sulfur colloid scintigraphy. This technique expands the scintigraphic armamentarium for evaluation of lower intestinal bleeding in infants and children.

  6. (99m)Tc-HYNIC-MPG: A novel SPECT probe for targeting mutated EGFR.

    PubMed

    Yan, Yan; Xiao, Zun-Yu; Song, Yan; Kang, Zhao-Ting; Wang, Ping; Sun, Xi-Lin; Shen, Bao-Zhong

    2015-04-01

    Mutated epidermal growth factor receptor (EGFR) is an important biomarker for cancer diagnosis and molecular target for many anticancer drugs. Localizing EGFR and evaluating EGFR mutational status can help to identify patients who are potentially the most suitable ones for targeted treatments. Hence, we developed a novel EGFR tyrosine kinase inhibitor labeled with (99m)Tc ((99m)Tc-HYNIC-MPG) and evaluated its EGFR binding capacity in vitro and in vivo. This molecular probe was synthesized by one-step method that is simple and highly efficient. Importantly, the uptake rate for (99m)Tc-HYNIC-MPG in the liver was as low as 28.44±0.15% (mean±SD, n=3). This finding presents for the first time that (99m)Tc-HYNIC-MPG can bind to mutated EGFR efficiently and thus provides a novel molecular tool to detect mutated EGFR and suppress tumorigenesis. PMID:25716904

  7. Electrical Generation

    NSDL National Science Digital Library

    2004-01-01

    This short page is a concise presentation of how electricity can be generated. Hotlinks to circuits and current electricity are embedded. The left navigation bar includes links to Energy and Work, Potential and Kinetic Energy, Types of Energy, Atoms, Circuits, and Electrical Generation.

  8. 99mTc-DMSA scanning to diagnose pyelonephritic scarring in children

    Microsoft Academic Search

    Barry A. Kogan; Robert Kay; Robert J. Wasnick; Helen Carty

    1983-01-01

    99mTechnetium-labeled dimercaptosuccinic acid (99mTc-DMSA) scanning provides superior quality images of renal parenchymal detail, which makes it highly sensitive for the diagnosis of pyelonephritic scarring. Unlike most other imaging techniques, radionuclide scanning is not affected by bowel gas or bony structures overlying the kidneys. This makes it particularly useful in children. Furthermore, renal scarring can be demonstrated by 99mTc-DMSA even before

  9. Role of Tc99m DMSA scintigraphy in the diagnosis of culture negative pyelonephritis

    Microsoft Academic Search

    Elena N. Levtchenko; Cécile Lahy; Jack Lévy; H. R. Ham; Amy Piepsz

    2001-01-01

    The aim of this work was to evaluate prospectively the proportion of children with a clinical and biological presentation\\u000a of acute pyelonephritis, abnormal Tc-99m dimercaptosuccinic acid (DMSA) scintigraphy and negative or equivocal urine cultures.\\u000a All patients aged 6 weeks to 15 years suspected of acute pyelonephritis (APN) were admitted to the Paediatric Department and\\u000a underwent Tc-99m DMSA scintigraphy within 3

  10. Alendronate Does Not Interfere with 99mTc-Methylene Diphosphonate Bone Scanning

    Microsoft Academic Search

    Jorge A. Carrasquillo; Millie Whatley; Valerie Dyer; William D. Figg; William Dahut

    Several studies have found that administration of etidronate results in competitive interference with 99mTc-labeled bone scanning reagents. In contrast, in other studies this problem was not encountered with other bisphosphonates. Methods: We prospectively studied 9 patients with hormone-refractory prostate cancer. 99mTc-methylene diphosphonate (MDP) bone scanning was performed before they received alendronate, and scanning was repeated a mean of 16.6 d

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

    Microsoft Academic Search

    Kent M. Reed

    1999-01-01

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

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

    Microsoft Academic Search

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

    1993-01-01

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

  13. [Mercaptoacetyltriglycine (MAG 3) 99mTc--a new radiopharmaceutic for uropoietic diagnoses].

    PubMed

    Marosová, A; Altmann, P; Komárek, P; Lepej, J

    1990-05-01

    The present authors show mercaptoacetyltrigylcine (MAG 3), labelled with 99mTc technetium, as a novel prospective diagnostic agent of the uropoietic system, replacing the injections of sodium iodohippurate labelled with 131I. The paper reports the procedure of labelling of this novel radiopharmaceutical with technetium 99mTc, evaluation of its quality by chromatographic methods, and biological distribution of MAG 3 in laboratory animals in comparison with the biodistribution of injections of sodium iodohippurate labelled with 131I. PMID:2144793

  14. Giant enhancement of oxygen mobility in high-Tc superconductors by atomic substitution

    Microsoft Academic Search

    J. L. Tallon; D. M. Pooke; M. P. Staines; M. E. Bowden; N. E. Flower; R. G. Buckley; M. R. Presland; R. L. Davis

    1990-01-01

    Most high-Tc superconductors require loading or unloading of oxygen after synthesis, in order to maximise the transition temperature, Tc. The rate of oxygen diffusion in dense, bulk material, is so slow as to be prohibitive, or at best calls for a lengthy manufacturing process. We report here that by a variety of aliovalent atomic substitutions in YBa2Cu3O7-delta, the rate of

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

    Microsoft Academic Search

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

    2007-01-01

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

  16. Origins of low- and high-pressure discontinuities of $T_{c}$ in niobium

    Microsoft Academic Search

    Malgorzata Wierzbowska; Stefano de Gironcoli; Paolo Giannozzi

    2005-01-01

    The discontinuities of $T_{c}$ in Niobium under pressure are examined by means of the pseudopotential plane-wave implementation of the electron-phonon coupling calculated from density-functional perturbation theory. Both low- and high-pressure discontinuities of $T_{c}$ have their origin in the Kohn anomalies and are caused by the low-frequency phonons, but the mechanism leading to the discontinuities is different in the two cases.

  17. The importance of 99m Tc DMSA scanning in the localization of childhood urinary tract infections

    Microsoft Academic Search

    N. Buyan; Z. E. Bircan; E. Hasano?lu; E. Öztürk; H. Bayhan; S. Rota

    1993-01-01

    The use of99mTechnetium dimercaptosuccinic acid (99mTc DMSA) scanning for the early diagnosis of upper urinary tract infections has been preferred for a few years. In this research\\u000a we investigated the use of99mTc DMSA scanning in the localization of renal parenchymal involvement in urinary tract infection. Twenty-four children presenting\\u000a with first acute urinary tract infection were studied. Investigations included physical examination,

  18. External monitoring of kidney transplant function using Tc99m(Sn)DTPA

    Microsoft Academic Search

    W. F. Sampson; M. A. Macleod; D. Warren

    1981-01-01

    The purpose of this study was to evaluate the use of an external counting technique to provide daily monitoring of kidney transplant function by measuring the renal clearance of Tc-99m(Sn)DTPA. During the first few weeks following transplant, 15 patients had their renal clearance of Tc-99m DTPA measured daily over periods of 5-24 hr. Clearance rates were compared with daily plasma

  19. External monitoring of kidney transplant function using Tc99m(Sn)DTPA

    Microsoft Academic Search

    W. F. D. Sampson; M. A. Macleod; D. Warren

    1981-01-01

    The purpose of this study was to evaluate the use of an external counting technique to provide daily monitoring of kidney transplant function by measuring the renal clearance of Tc-99m(SN)DTPA. During the first few weeks following transplant, 15 patients had their renal clearance of Tc-99m DTPA measured daily over periods of 5 to 24 h. Clearance rates were compared with

  20. Characterization of Farnesylated Protein Tyrosine Phosphatase TcPRL-1 from Trypanosoma cruzi

    Microsoft Academic Search

    Ileana C. Cuevas; Peter Rohloff; Daniel O. Sanchez; Roberto Docampo

    2005-01-01

    Protein tyrosine kinases and phosphatases play important roles in the regulation of cell growth, develop- ment, and differentiation. We report here the identification in Trypanosoma cruzi of a gene (TcPRL-1) encoding a protein tyrosine phosphatase. The predicted protein (TcPRL-1) shares ca. 35% identity with the mammalian protein tyrosine phosphatase known as phosphatase of regenerating liver 1 (PRL-1). Four copies of

  1. Diagnosis of hepatobiliary disease in infants and children with Tc99m-diethyl-IDA imaging

    Microsoft Academic Search

    RYOJI OHI; WILLIAM C. KLINGENSMITH; JOHN R. LILLY

    1981-01-01

    Thirteen infants and children from 42 days to 14 years old with hepatobiliary disease underwent Tc-99m-diethyl-IDA hepatobiliary imaging. Five patients had biliary atresia, four had biliary hypoplasia, two had neonatal hepatitis, and there were single examples of alpha-1-antitrypsin deficiency and congenital hepatic fibrosis. Tc-99m-diethyl-IDA imaging accurately differentiated biliary atresia (complete bile duct obstruction) from other forms of childhood hepatobiliary disease

  2. Comparative Analysis of the Recently Discovered hAT Transposon TcBuster in Human Cells

    PubMed Central

    Woodard, Lauren E.; Li, Xianghong; Malani, Nirav; Kaja, Aparna; Hice, Robert H.; Atkinson, Peter W.; Bushman, Frederic D.; Craig, Nancy L.; Wilson, Matthew H.

    2012-01-01

    Background Transposons are useful tools for creating transgenic organisms, insertional mutagenesis, and genome engineering. TcBuster, a novel hAT-family transposon system derived from the red flour beetle Tribolium castaneum, was shown to be highly active in previous studies in insect embryoes. Methodology/Principal Findings We tested TcBuster for its activity in human embryonic kidney 293 (HEK-293) cells. Excision footprints obtained from HEK-293 cells contained small insertions and deletions consistent with a hAT-type repair mechanism of hairpin formation and non-homologous end-joining. Genome-wide analysis of 23,417 piggyBac, 30,303 Sleeping Beauty, and 27,985 TcBuster integrations in HEK-293 cells revealed a uniquely different integration pattern when compared to other transposon systems with regards to genomic elements. TcBuster experimental conditions were optimized to assay TcBuster activity in HEK-293 cells by colony assay selection for a neomycin-containing transposon. Increasing transposon plasmid increased the number of colonies, whereas gene transfer activity dependent on codon-optimized transposase plasmid peaked at 100 ng with decreased colonies at the highest doses of transposase DNA. Expression of the related human proteins Buster1, Buster3, and SCAND3 in HEK-293 cells did not result in genomic integration of the TcBuster transposon. TcBuster, Tol2, and piggyBac were compared directly at different ratios of transposon to transposase and found to be approximately comparable while having their own ratio preferences. Conclusions/Significance TcBuster was found to be highly active in mammalian HEK-293 cells and represents a promising tool for mammalian genome engineering. PMID:23166581

  3. 99mTc-EDDA/HYNIC-TOC in the management of medullary thyroid carcinoma.

    PubMed

    Parisella, Maria; D'Alessandria, Calogero; van de Bossche, Bieke; Chianelli, Marco; Ronga, Giuseppe; Papini, Enrico; Mikolajczak, Renata; Letizia, Claudio; De Toma, Giorgio; Veneziani, Augusto; Scopinaro, Francesco; Signore, Alberto

    2004-04-01

    An early diagnosis of distant metastases or local recurrences of medullary thyroid carcinoma (MTC) can be achieved by several conventional radiological modalities (e.g., ultrasonography, computed tomography [CT], and magnetic resonance imaging [MRI] as well as by radioisotopic procedures, such as positron emission tomography (PET), scintigraphy with different types of radiopharmaceuticals, and radiolabeled receptor-ligands in particular. The aim of this study was to evaluate the clinical utility of 99mTc-EDDA/HYNIC-TOC, a new octreotide derivative, to detect recurrences of disease or distant metastases in MTC. Images obtained of 5 patients with high levels of serum calcitonin were compared to findings obtained with other diagnostic procedures: 111In-octreotide, 99mTc-DMSA-V, 18F-flouro-D-deoxyglucose-PET, and CT/MRI. 99mTc-EDDA/HYNIC-TOC was positive in all patients and showed 15 areas of pathological uptake in the cervical and mediastinal regions. 111In-octreotide was positive in 3 of 3 patients and showed 4 areas, compared to 8 of 99mTc-EDDA/HYNIC-TOC. 99mTc-V-DMSA was positive in 3 of 4 patients but showed 6 pathological areas, compared to 13 of 99mTc-EDDA/HYNIC-TOC. 18F-FDG-PET was positive in 5 of 5 patients but showed only 11 areas, compared to 15 of 99mTc-EDDA/HYNIC-TOC. The CT scan was positive in only 2 patients. In conclusion, 99mTc-EDDA/HYNIC-TOC detected more sites of pathological uptake than other modalities, showed better imaging properties than 111In-octreotide, and might be the radiopharmaceutical of choice for providing a rationale for radioisotopic therapy. PMID:15186602

  4. 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.

  5. Regional respiratory clearance of aerosolized \\/sup 99m\\/Tc-DTPA: posture and smoking effects

    Microsoft Academic Search

    D. J. Dusser; B. D. Minty; M. A. Collignon; D. Hinge; L. G. Barritault; G. J. Huchon

    1986-01-01

    We studied 10 healthy nonsmokers and 8 healthy smokers, in both the upright and supine position, to investigate whether regional differences in respiratory clearance of technetium-99m-labeled diethylenetriamine pentaacetic acid \\/sup 99m\\/Tc-DTPA (RC-DTPA) existed and to assess the influence of posture and smoking on the regional RC-DTPA. RC-DTPA was assessed by the lung clearance rates (%\\/min) of aerosolized \\/sup 99m\\/Tc-DTPA (0.8

  6. Tc-99m(V)-DMSA in wound infection after closure of an ileostomy.

    PubMed

    Chang, Ming-Zhe; Tsai, Chien-Chung; Hung, Guang-Uei; Lin, Wan-Yu

    2005-12-01

    We present a 71-year-old man who underwent closure of an ileostomy and had a fever seven days post surgery. Both Tc-99m(V)-dimercaptosuccinic acid (DMSA) and gallium-67 citrate scans showed increased tracer accumulation in the right lower quadrant of the abdomen. Tc-99m(V)-DMSA scintigraphy can be a rapid alternative tool in the detection of wound infection in patients after ileostomy closure. PMID:16445002

  7. Dose calibrator linearity test: 99mTc versus 18F radioisotopes*

    PubMed Central

    Willegaignon, José; Sapienza, Marcelo Tatit; Coura-Filho, George Barberio; Garcez, Alexandre Teles; Alves, Carlos Eduardo Gonzalez Ribeiro; Cardona, Marissa Anabel Rivera; Gutterres, Ricardo Fraga; Buchpiguel, Carlos Alberto

    2015-01-01

    Objective The present study was aimed at evaluating the viability of replacing 18F with 99mTc in dose calibrator linearity testing. Materials and Methods The test was performed with sources of 99mTc (62 GBq) and 18F (12 GBq) whose activities were measured up to values lower than 1 MBq. Ratios and deviations between experimental and theoretical 99mTc and 18F sources activities were calculated and subsequently compared. Results Mean deviations between experimental and theoretical 99mTc and 18F sources activities were 0.56 (± 1.79)% and 0.92 (± 1.19)%, respectively. The mean ratio between activities indicated by the device for the 99mTc source as measured with the equipment pre-calibrated to measure 99mTc and 18F was 3.42 (± 0.06), and for the 18F source this ratio was 3.39 (± 0.05), values considered constant over the measurement time. Conclusion The results of the linearity test using 99mTc were compatible with those obtained with the 18F source, indicating the viability of utilizing both radioisotopes in dose calibrator linearity testing. Such information in association with the high potential of radiation exposure and costs involved in 18F acquisition suggest 99mTc as the element of choice to perform dose calibrator linearity tests in centers that use 18F, without any detriment to the procedure as well as to the quality of the nuclear medicine service. PMID:25798005

  8. Asialoglycoprotein-receptor-targeted hepatocyte imaging using 99mTc galactosylated chitosan

    Microsoft Academic Search

    Eun-Mi Kim; Hwan-Jeong Jeong; Se-Lim Kim; Myung-Hee Sohn; Jae-Woon Nah; Hee-Seung Bom; In-Kyu Park; Chong-Su Cho

    2006-01-01

    This study investigated the usefulness of 99mTc hydrazinonicotinamide-galactosylated chitosan (HGC) in hepatocyte imaging. HGC was obtained by coupling the galactose moiety of both lactobionic acid and succinimidyl 6-hydrazinonicotinate hydrochloride (succinimidyl HYNIC). The coupled product was then radiolabeled with 99mTc using stannous chloride and tricine as reducing agent and coligand, respectively. Labeling efficiency was >90% both in room temperature and in

  9. Detection of gastritis by /sup 99m/Tc-labeled red-blood-cell scintigraphy

    SciTech Connect

    Wilton, G.P.; Wahl, R.L.; Juni, J.E.; Froelich, J.W.

    1984-10-01

    Gastritis is a common condition, with a variety of causes, that is diagnosed most often by barium upper gastrointestinal tract series or endoscopy. The authors report a case in which gastritis without active bleeding was apparent in scintiscans obtained during the evaluation of GI bleeding using /sup 99m/Tc-labeled red blood cells (TcRBC). The scintigraphic findings that suggest gastritis are described.

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

    SciTech Connect

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

    1994-05-01

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

  11. Water-stable fac-{TcO?}? complexes - a new field of technetium chemistry.

    PubMed

    Braband, Henrik

    2011-01-01

    The development of technetium chemistry has been lagging behind that of its heavier congener rhenium, primarily because the inherent radioactivity of all Tc isotopes has limited the number of laboratories that can study the chemistry of this fascinating element. Although technetium is an artificial element, it is not rare. Significant amounts of the isotope (99)Tc are produced every day as a fission byproduct in nuclear power plants. Therefore, a fundamental understanding of the chemistry of (99)Tc is essential to avoid its release into the environment. In this article the chemistry of technetium at its highest oxidation state (+VII) is reviewed with a special focus on recent developments which make water-stable complexes of the general type [TcO(3)(tacn-R)](+) (tacn-R = 1,4,7-triazacyclononane or derivatives) accessible. Complexes containing the fac-{TcO(3)}(+) core display a unique reactivity. In analogy to [OsO(4)] and [RuO(4)], complexes containing the fac-{TcO(3)}(+) core undergo with alkenes metal-mediated, vicinal cis-dihydroxylation reactions (alkene-glycol interconversion) in water via a (3+2)-cycloaddition reaction. Therefore, water-stable fac-{(99m)TcO(3)}(+) complexes pave the way for a new labeling strategy for radiopharmaceutical applications, based on (3+2)-cycloaddition reactions. This new concept for the labeling of biomolecules with small [(99m)TcO(3)(tacn-R)](+)-type complexes by way of a (3+2)-cycloaddition with alkenes is discussed in detail. The herein reported developments in high-valent technetium chemistry create a new field of research with this artificial element. This demonstrates the potential of fundamental research to provide new impetus of innovation for the development of new methods for radiopharmaceutical applications. PMID:22054130

  12. Influence of strain and composition on Tc in FeSe1-xTex films

    NASA Astrophysics Data System (ADS)

    Horide, Tomoya; Sanyoushi, Masahiro; Ichinose, Ataru; Matsumoto, Kaname

    2014-12-01

    FeSe1-xTex films with wide ranging strain and composition were deposited using pulsed laser deposition, and lattice parameters and critical temperature (Tc) were evaluated in the films to understand influence of strain and composition on Tc of FeSe1-xTex films. c was larger than that in bulk and a was smaller than the bulk value due to strain (substrate effect), where c and a are c-axis length (perpendicular to film surface) and a-axis length (parallel to film surface) in the c-axis oriented FeSe1-xTex films. Depending on c value, two kinds of regions were observed regarding relationship between a and Tc. In the case of small c (c < 5.9 Å: small Te content), lattice parameter dependence of Tc in the films was different from that in bulk with different Te content, and Tc strongly increased with decrease in a. On the other hand, in the case of large c (c > 5.9 Å: large Te content), lattice parameter dependence of Tc in the films was similar to that in bulk with different Te content, and in-plane film strain did not vary Tc. In first principle band calculation, ab-plane bi-axial strain varied the Fermi surface in FeSe (c < 5.9 Å), but such strain-induced variation of Fermi surface was smaller in FeSe0.5Te0.5 (c > 5.9 Å), which is consistent with the experimental results. The present results suggest that much higher Tc than the bulk values is obtained by decreasing a (compressive ab-plane strain) with keeping c < 5.9 Å (small Te content) using hydrostatic pressure and/or film strain.

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

    Microsoft Academic Search

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

    1993-01-01

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

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

    Microsoft Academic Search

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

    1993-01-01

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

  15. Parathyroid adenoma detected with 99mTc-tetrofosmin dual-phase scintigraphy: a case report

    PubMed Central

    2014-01-01

    Background Tc-sestamibi is the most frequently used radionuclide agent for the detection of parathyroid adenomas in the clinical setting. However, Tc-tetrofosmin is another such agent that may be used for this purpose. This case report presents the significance and practicality of 99mTc-tetrofosmin for the diagnosis of parathyroid adenomas with probable high p-glycoprotein levels. Case presentation A 45-year-old woman was referred to our Nuclear Department with a palpable neck nodule suspicious for parathyroid adenoma. She had no significant medical history or other accompanying symptoms. Blood examination results were normal with the exception of the parathormone level which was high at 167.2 pg/ml. Neck ultrasonography revealed a hypoechoic mass near the lower pole of the thyroid gland. 99m Tc-tetrofosmin dual-phase scintigraphy with early and delayed images was performed and the results supported the presupposition of parathyroid adenoma as shown by increased radiopharmaceutical levels near the lower left thyroid gland on the early image that disappeared on the delayed image. Moreover, TcO4? thyroid scintigraphy results excluded thyroid pathology. Two months after the diagnosis, parathyroidectomy was successfully performed without postoperative complications. The pathology report and clinical response to a gradual decrease of parathormone confirmed the initial diagnosis. Conclusion We strongly recommend the use of reverse 99m Tc-tetrofosmin scintigraphy as a useful and safe examination technique for the diagnosis of parathyroid adenomas. PMID:24894734

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

    PubMed Central

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

    2014-01-01

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

  17. 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.

  18. /sup 99m/Tc(Sn)-N-pyridoxylaminates: a new series of hepatobiliary imaging agents

    SciTech Connect

    Kato-Azuma, M.

    1982-06-01

    Three derivatives of N-pyridoxylamino acid were synthesized: /sup 99m/Tc(Sn)-N-pyridoxylphenylalanine, -N-pyridoxyltryptophan, and -N-pyridoxyl-5-methyltryptophan. The chemical and biologic properties of each complex was found to be quite analogous to those of the corresponding /sup 99m/Tc(Sn)pyridoxylideneaminate. In rats, /sup 99m/Tc(Sn)-N-pyridoxyl-5-methyltryptophan (/sup 99m/Tc(Sn)PHMT) showed rapid blood clearance, fast hepatobiliary transit, low urinary excretion, and no intestinal reabsorption. Over 90% of the dose arrived in the intestine through the liver at 30 min after i.v. administration, whereas only 2% of the dose escaped through the kidneys. In rabbits the gallbladder was clearly visualized within 5 min of injection and no renal or bladder images were noted on any scintiphotos. The BSP (sulfobromophthalein) intervention study revealed that the biliary excretion of /sup 99m/Tc(Sn)PHMT is much more resistant than that of /sup 99m/Tc(Sn) diethyl-IDA to the intervention of BSP and hence to serum bilirubin. Toxicity studies on PHMT and Sn-PHMT indicated a wide margin of safety for the proposed human dose.

  19. TC10 controls human myofibril organization and is activated by the sarcomeric RhoGEF obscurin

    PubMed Central

    Coisy-Quivy, Marjorie; Touzet, Olivia; Bourret, Annick; Hipskind, Robert A.; Mercier, Jacques; Fort, Philippe; Philips, Alexandre

    2009-01-01

    Summary The contractile activity of striated muscle depends on myofibrils that are highly ordered macromolecular complexes. The protein components of myofibrils are well characterized, but it remains largely unclear how signaling at the molecular level within the sarcomere and the control of assembly are coordinated. We show that the Rho GTPase TC10 appears during differentiation of human primary skeletal myoblasts and it is active in differentiated myotubes. We identify obscurin, a sarcomere-associated protein, as a specific activator of TC10. Indeed, TC10 binds directly to obscurin via its predicted RhoGEF motif. Importantly, we demonstrate that obscurin is a specific activator of TC10 but not the Rho GTPases Rac and Cdc42. Finally, we show that inhibition of TC10 activity by expression of a dominant-negative mutant or its knockdown by expression of specific shRNA block myofibril assembly. Our findings reveal a novel signaling pathway in human skeletal muscle that involves obscurin and the Rho GTPase TC10 and implicate this pathway in new sarcomere formation. PMID:19258391

  20. 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.

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

    SciTech Connect

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

    1984-10-01

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

  2. Generation and characterization of nanobodies targeting PSMA for molecular imaging of prostate cancer.

    PubMed

    Evazalipour, Mehdi; D'Huyvetter, Matthias; Tehrani, Bahram Soltani; Abolhassani, Mohsen; Omidfar, Kobra; Abdoli, Shahriyar; Arezumand, Roghaye; Morovvati, Hamid; Lahoutte, Tony; Muyldermans, Serge; Devoogdt, Nick

    2014-01-01

    Nanobodies show attractive characteristics for tumor targeting in cancer diagnosis and therapy. A radiolabeled nanobody binding the prostate-specific membrane antigen (PSMA) could offer a noninvasive strategy to select prostate cancer patients eligible for PSMA-targeted therapies. We here describe the generation, production and in vivo evaluation of anti-PSMA nanobodies. Nanobodies were derived from heavy-chain-only antibodies, raised in immunized dromedaries. Binding characteristics were evaluated through ELISA and flow cytometry. Selected nanobodies were radiolabeled with (99m) Tc at their hexahistidine tail, after which cell binding capacity and internalization were evaluated on PSMA(pos) LNCaP and PSMA(neg) PC3 cell lines. In vivo tumor targeting was analyzed in both LNCaP and PC3 xenografted mice through SPECT/microCT and tissue sampling. A panel of 72 generated clones scored positive on ELISA, all contributing to three nanobody groups, of which group 3 dominated with 70 clones. ELISA and FACS analysis led to the selection of two dominant nanobodies. (99m) Tc-labeled PSMA6 and PSMA30 both showed specific binding on LNCAP cells, but not on PC3 cells. (99m) Tc-PSMA30 internalized significantly more in LNCaP cells compared to (99m) Tc-PSMA6. Higher absolute tumor uptake and tumor-to-normal organ ratios were observed for (99m) Tc-PSMA30 compared with (99m) Tc-PSMA6 and a (99m) Tc-control nanobody in LNCaP but not in PC3 tumor-bearing mice. PSMA30 nanobody has improved targeting characteristics both in vitro as well as in vivo compared with PSMA6 and the control nanobody, and was therefore selected as our in-house-developed lead compound for PSMA targeting. PMID:24700748

  3. (Nb, Ti)3Sn Superconducting Magnet Operated at 11 K in Vacuum Using High-Tc (Bi, Pb)2Sr2Ca2Cu3O10 Current Leads

    Microsoft Academic Search

    Kazuo Watanabe; Yutaka Yamada; Junji Sakuraba; Fumiaki Hata; Chin Kung Chong; Tsuginori Hasebe; Mamoru Ishihara

    1993-01-01

    A conduction-cooled superconducting magnet using high-Tc oxide current leads was successfully demonstrated. We succeeded in constructing the (Nb, Ti)3Sn multifilamentary superconducting magnet system without liquid helium, which is operated at 11 K in vacuum using a cryocooler and generates a magnetic field of 4.6 T in a 50 mm bore (38 mm room temperature bore). Use of (Bi, Pb)2Sr2Ca2Cu3O10 current

  4. 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.

  5. 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)

  6. 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

  7. 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.

  8. Immunomodulation by Trypanosoma cruzi: Toward Understanding the Association of Dendritic Cells with Infecting TcI and TcII Populations

    PubMed Central

    da Costa, Thiago Alvares; Silva, Marcos Vinicius; Mendes, Maria Tays; Carvalho-Costa, Tamires Marielem; Batista, Lara Rocha; Lages-Silva, Eliane; Rodrigues, Virmondes; Oliveira, Carlo Jose; Ramirez, Luis Eduardo

    2014-01-01

    Dendritic cells (DCs) are major immune components, and depending on how these cells are modulated, the protective host immune response changes drastically. Trypanosoma cruzi is a parasite with high genetic variability and modulates DCs by interfering with their capacity for antigen recognition, migration, and maturation. Despite recent efforts, the association between DCs and T. cruzi I (TcI) and TcII populations is unknown. Herein, it was demonstrated that AQ1.7 and MUTUM TcI strains present low rates of invasion of bone marrow-derived DCs, whereas the 1849 and 2369 TcII strains present higher rates. Whereas the four strains similarly induced the expression of PD-L1, the production and expression of IL-10 and TLR-2, respectively, in DCs were differentially increased. The production of TNF-?, IL-12, IL-6, and CCL2 and the expression of CD40, CD80, MHC-II, CCR5, and CCR7 changed depending on the strain. The 2369 strain yielded the most remarkable results because greater invasion correlated with an increase in the levels of anti-inflammatory molecules IL-10 and PD-L1 but not with a change in the levels of TNF-?, MHC-II, or CD40 molecules. These results suggest that T. cruzi strains belonging to different populations have evolved specific evasion strategies that subvert DCs and consequently the host response. PMID:25371910

  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. [99mTc]HYNIC-RGD for imaging integrin alphavbeta3 expression.

    PubMed

    Decristoforo, Clemens; Faintuch-Linkowski, Bluma; Rey, Ana; von Guggenberg, Elisabeth; Rupprich, Marco; Hernandez-Gonzales, Ignacio; Rodrigo, Teodoro; Haubner, Roland

    2006-11-01

    There has been increasing interest in peptides containing the Arg-Gly-Asp (RGD) sequence for targeting of alpha(v)beta(3) integrins to image angiogenesis. [(18)F]Galacto-RGD has been successfully used for positron emission tomography applications in patients. Here we report on the preclinical characterization of a (99m)Tc-labeled derivative for single-photon emission computed tomography. c(RGDyK) was derivatized with HYNIC at the amino group of the lysine [c(RGDyK(HYNIC)) or HYNIC-RGD]. (99m)Tc labeling was performed using coligands (tricine and EDDA), as well as (99m)Tc(CO)(3)(H(2)O)(3). Radiolabeled peptides were characterized with regard to lipophilicity, protein binding and stability in buffer, serum and tissue homogenates. Integrin receptor activity was determined in internalization assays using alpha(v)beta(3)-receptor-positive M21 and alpha(v)beta(3)-receptor-negative M21L melanoma cells. Biodistribution was evaluated in normal and nude mice bearing M21, M21L and small cell lung tumors. HYNIC-RGD could be labeled at high specific activities using tricine, tricine-trisodium triphenylphosphine 3,3',3''-trisulfonate (TPPTS), tricine-nicotinic acid (NA) or EDDA as coligands. [(99m)Tc]EDDA/HYNIC-RGD, [(99m)Tc]tricine-TPPTS/HYNIC-RGD and [(99m)Tc]tricine-NA/HYNIC-RGD showed protein binding (<5%) considerably lower than [(99m)Tc](CO)(3)/HYNIC-RGD and [(99m)Tc]tricine/HYNIC-RGD. [(99m)Tc]EDDA/HYNIC-RGD revealed high in vitro stability accompanied by low lipophilicity with a log P value of -3.56, comparable to that of [(18)F]Galacto-RGD. In M21 cells for this compound, the highest level of specific and rapid cell uptake (1.25% mg protein(-1)) was determined. In vivo, rapid renal excretion, low blood retention, low liver and muscle uptakes and low intestinal excretion 4 h postinjection were observed. Tumor uptake values were 2.73% ID/g in M21 alpha(v)beta(3)-receptor-positive tumors versus 0.85% ID/g in receptor-negative tumors 1 h postinjection. Small cell lung tumors could be visualized using gamma camera imaging. [(99m)Tc]EDDA/HYNIC-RGD shows encouraging properties to target alpha(v)beta(3) receptors in vivo with high stability and favorable pharmacokinetics. Tumor uptake studies showed specific targeting of alpha(v)beta(3)-receptor-positive tumors with tumor-to-organ ratios comparable to those of [(18)F]Galacto-RGD. PMID:17127166

  11. 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).

  12. Vibration generators

    SciTech Connect

    Lerwill, W.E.

    1980-09-16

    Apparatus for generating vibrations in a medium, such as the ground, comprises a first member which contacts the medium, means , preferably electromagnetic, which includes two relatively movable members for generating vibrations in the apparatus and means operatively connecting the said two members to said first member such that the relatively amplitudes of the movements of said three members can be adjusted to match the impedances of the apparatus and the medium.

  13. Technetium-carbon multiple bonds. Synthesis and structure of Tc(=C=CHPh)Cl(dppe)[sub 2] and [Tc([triple bond]C-CH[sub 2]-t-Bu)Cl(dppe)[sub 2

    SciTech Connect

    Burrell, A.K.; Bryan, J.C.; Kubas, G.J. (Los Alamos National Lab., NM (United States))

    1994-04-01

    The 16-electron complex TcCl(dppe)[sub 2] reacts with terminal alkynes to form neutral vinylidene complexes of the type Tc(=C=CHR)Cl(dppe)[sub 2] (R = Ph, Me, t-Bu). Treatment of these vinylidene complexes with acid (HBF[sub 4] for R = Ph, HNMe[sub 3]BPh[sub 4] for R = t-Bu) yields the respective terminal carbyne complexes Tc([triple bond]CCH[sub 2]R)-Cl(dppe)[sub 2][sup +] (R = Ph, t-Bu). These vinylidene and carbyne compounds represent the first examples of technetium carbenes or carbynes. X-ray structures of Tc(=C=CHPh)Cl(ddpe)[sub 2] and Tc([triple bond]CCH[sub 2]-t-Bu)Cl(dppe)[sub 2[minus]+] were determined, and the Tc-C bond lengths obtained were 1.861(9) and 1.724(7) A, respectively. 13 refs., 2 figs.

  14. 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

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

    PubMed

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

    2014-10-01

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

  16. Expression, immunolocalization and serodiagnostic value of Tc38630 protein from Trypanosoma congolense.

    PubMed

    Mochabo, Kennedy Miyoro; Zhou, Mo; Suganuma, Keisuke; Kawazu, Shin-Ichiro; Suzuki, Yasuhiko; Inoue, Noboru

    2013-09-01

    Animal African trypanosomosis is a serious constraint to livestock sector development in sub-Saharan Africa. The disease, mainly caused by Trypanosoma congolense, has a limitation in its diagnosis and treatment. There is urgent need for a simple, rapid detection technique to replace the few available serological tests that are of variable sensitivity and specificity. Currently, there is a promising use of recombinant proteins to improve on the trypanosome lysate to detect antibodies. In this respect, we have identified a stage-specific gene that is relatively highly expressed in metacyclic and blood trypomastigotes of T. congolense. According to previously obtained differential protein expression data, the gene TcIL3000.0.38630 (1,236 bp) is by 8.5 times more expressed in metacyclic and blood trypomastigotes than in procyclic trypomastigotes and epimastigotes. The same stage specific expression pattern was shown in Western blot analysis. In addition, in confocal laser scanning microscopy the Tc38630 protein was present in the cytosol and on the cell surface of metacyclic and blood trypomastigotes. Through bioinformatics, the Tc38630 had N-terminal signal sequence, hydrophilic extracellular domain, single transmembrane alpha-helix and short cytoplasmic domain, which is characteristic of the Trypanosoma brucei invariant surface glycoprotein. However, unlike T. brucei invariant surface glycoprotein, the Tc38630 existed as a single copy gene with a probable allelic polymorphism at the Nar I restriction site. The recombinant Tc38630-based ELISA detected antibodies against Tc38630 as early as 7 days post infection in experimentally infected mouse model. Taken together, our results suggest that the Tc38630 is a novel potential diagnostic antigen of Animal African trypanosomosis. PMID:23820607

  17. The role of 99mTc(V)-DMSA scan as compared to 99mTc-MDP and CT scans in imaging the primary tumor and metastases of osteosarcoma.

    PubMed

    Zissimopoulos, Athanassios; Zanglis, Antonios; Andreopoulos, Dimitrios; Baziotis, Nikolaos

    2005-01-01

    The oncophilic complex of technetium-99m labeled pentavalent dimercaptosuccinic acid (99mTc(V)-DMSA) has been successfully used for the detection of primary and metastatic medullary thyroid cancer and for imaging various soft tissue tumors like lung, brain and prostate cancer. In this article, the role of 99mTc(V)-DMSA in the diagnosis of the primary tumor and metastases of osteosarcoma patients as compared to the 99mTc-MDP scan and the CT scan was studied. Twenty-eight patients with bone disease were referred to the Nuclear Medicine Department of Saint Savas Oncology Hospital in Athens from the Orthopedics Department of the same Hospital. From them, 18 (Group A) had osteosarcoma, 7 (Group B) osteomyelitis and 3 (Group C) bone fractures. The final diagnosis was made after fine needle aspiration biopsy. All patients were subjected to the 99mTc(V)-DMSA scan, the standard bone scan (99mTc-MDP) and CT scan. Group A patients showed a selective uptake of 99mTc(V)-DMSA in the primary tumor region. No abnormal 99mTc(V)-DMSA uptake was observed in the patients of Groups B and C. The 99mTc(V)-DMSA scan was found to be superior to the 99mTc-MDP and the CT scans in identifying metastases of osteosarcoma. Sensitivity was 100%, 86% and 98% respectively. PMID:16390022

  18. Neutron depolarization effects in a high-Tc superconductor (abstract)

    NASA Astrophysics Data System (ADS)

    Nunes, A. C.; Pickart, S. J.; Crow, L.; Goyette, R.; McGuire, T. R.; Shinde, S.; Shaw, T. M.

    1988-11-01

    Using the polarized beam small-angle neutron scattering spectrometer at the Rhode Island Nuclear Science Center Reactor, we have observed significant depolarization of a neutron beam by passage through polycrystalline high-Tc superconductors, specifically 123 Y-Ba-Cu-O prepared and characterized at the IBM Watson Research Center. We believe that this technique will prove useful in studying aspects of these materials, such as the penetration depth of shielding currents, the presence and structure of trapped flux vortices, and grain size effects on the supercurrent distribution in polycrystalline samples. The two samples showed sharp transitions at 87 and 89 K, and have been studied at temperatures of 77 K; the second sample has also been studied at 4 K. The transition to the superconducting state was monitored by the shift in resonant frequency of a coil surrounding the sample. No measurable depolarization was observed in either sample at 77 K in both the field-cooled and zero-field-cooled states, using applied fields of 0 (nominal), 54, and 1400 Oe. This negative result may be connected with the fact that the material is still in the reversible region as indicated by susceptibility measurements, but it allows an estimate of the upper bound of possible inhomogeneous internal fields, assuming a distance scale for the superconducting regions. For the 10-?m grain size suggested by photomicrographs, this upper bound for the field turns out to be 1.2 kOe, which seems reasonable. At 4 K a significant depolarization was observed when the sample was cooled in low fields and a field of 1400 Oe was subsequently applied. This result suggests that flux lines are penetrating the sample. Further investigations are being carried out to determine the field and temperature dependence of the depolarization, and attempts will be made to model it quantitatively in terms of possible internal field distributions. We are also searching for possible diffraction effects from ordered vortex arrays and plan to extend the measurements to Bi and Tl compositions. These results will be reported in detail elsewhere.

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

    PubMed

    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

    2015-04-01

    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

  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. Solar Generator

    NASA Technical Reports Server (NTRS)

    1985-01-01

    The Vanguard I dish-Stirling module program, initiated in 1982, produced the Vanguard I module, a commercial prototype erected by the Advanco Corporation. The module, which automatically tracks the sun, combines JPL mirrored concentrator technology, an advanced Stirling Solar II engine/generator, a low cost microprocessor-controlled parabolic dish. Vanguard I has a 28% sunlight to electricity conversion efficiency. If tests continue to prove the system effective, Advanco will construct a generating plant to sell electricity to local utilities. An agreement has also been signed with McDonnell Douglas to manufacture a similar module.

  2. Technetium Tc-99m pyrophosphate for cerebrospinal fluid leaks: radiopharmaceutical considerations.

    PubMed

    Ponto, James A; Graham, Michael M

    2014-01-01

    OBJECTIVE To confirm the anticipated image quality and absence of adverse reactions in patients undergoing clinical practice cerebrospinal fluid (CSF) leak imaging procedures using technetium Tc-99m pyrophosphate (PYP). METHODS Following the recent discontinuation of preservative-free calcium trisodium diethylene triamine pentaacetic acid kits, PYP was selected as a suitable alternative for CSF leak imaging procedures. Procedures were established for its preparation and dispensing, paying special attention to safety considerations, and its use in clinical practice was implemented. Medical records, including images, were reviewed for the first 15 patients undergoing clinical practice CSF imaging procedures using Tc-99m PYP to confirm anticipated image quality and absence of adverse effects. RESULTS Review of CSF leak imaging procedures using Tc-99m PYP in 15 patients showed images to be of uniformly high quality. The vast majority of injected radiopharmaceutical remained in the CSF throughout the duration of the imaging procedure, allowing visualization of CSF leaks. Only a small amount of Tc-99m PYP diffused into the blood with resultant uptake on the skeleton and excretion into the urine, which did not interfere with image interpretation. No adverse reactions were noted in any of the patients. CONCLUSION With proper attention to safety considerations, Tc-99m PYP is a safe and effective alternative for performing CSF leak imaging procedures. PMID:24257695

  3. High Field determination of superconducting fluctuations in high-Tc cuprates

    NASA Astrophysics Data System (ADS)

    Rullier-Albenque, F.; Alloul, H.; Colson, D.; Forget, A.

    2013-07-01

    Large pulsed magnetic fields up to 60 Tesla are used to suppress the contribution of superconducting fluctuations (SCF) to the ab-plane conductivity above Tc in a series of YBa2Cu3O6+x single crystals. The fluctuation conductivity is found to vanish nearly exponentially with temperature, allowing us to determine precisely the field H'c(T) and the temperature T'c above which the SCFs are fully suppressed. T'c is always found much smaller than the pseudogap temperature A careful investigation near optimal doping shows that T'c is higher than the pseudogap T*, which indicates that pseudogap cannot be assigned to preformed pairs. For nearly optimally doped samples, the fluctuation conductivity can be accounted for by gaussian fluctuations following the Ginzburg-Landau scheme. A phase fluctuation contribution might be invoked for the most underdoped samples in a T range which increases when controlled disorder is introduced by electron irradiation. Quantitative analysis of the fluctuating magnetoconductance allows us to determine the critical field Hc2(0) which is found to be quite similar to H'c(0) and to increase with hole doping. Studies of the incidence of disorder on both T'c and T* enable us to propose a three dimensional phase diagram including a disorder axis, which allows to explain most observations done in other cuprate families.

  4. The contribution of 99mTc-pyrophosphate tomoscintigraphy in the evaluation of necrotic myocardial lesions.

    PubMed

    Bourgeois, P; Depaepe, A; Demey, P; Merveille, P; Van Vooren, J P; Frühling, J

    1989-01-01

    Diagnostic contribution of Conventional Planar Scintigraphy (CPSc) and Single Photon Emission Computed Tomoscintigraphy (SPECT), using 99mTc-Pyrophosphate (99mTc-PYP), have been compared in 49 patients with either transmural (T.I., N = 40), or non-transmural (N.T.I., N = 9) infarction. Sensitivity ratios were, respectively for CPSc and SPECT, 75% and 100% in T.I., 78% and 88% in N.T.I. CPSc was non-diagnostic in 6 out of 49 patients, SPECT in only 1. Extent of the necrotizing process was better delineated on SPECT studies than on CPSc. Specificity of 99mTc-PYP tomoscintigraphy evaluated in a group of 6 young (under 40 years old) normal patients was 6/6 (100%). In nine out of ten additional patients without proven infarction who had underwent contrast coronarography within two weeks after a positive 99mTc-PYP SPECT study, significant stenosis (greater than 50%) were found on arteries supplying blood to pathologic territories as demonstrated on tomoscans. It is concluded that 99mTc-PYP SPECT is a very sensitive and specific way--better than CPSc--in the diagnosis as well as in the evaluation of the extent of necrotic myocardial process. PMID:2551114

  5. Tc-99m macro aggregated albumin scintigraphy – indications other than pulmonary embolism: A pictorial essay

    PubMed Central

    Gandhi, Sunny J; Babu, Sanjay; Subramanyam, Padma; Shanmuga Sundaram, Palaniswamy

    2013-01-01

    Introduction: Tc-99m macro aggregated albumin (MAA) is synonymous for lung perfusion scintigraphy and is part of the study in the evaluation of pulmonary thromboembolism. We wanted to highlight the utilities of Tc-99m MAA other than pulmonary embolism as a pictorial assay. Materials and Methods: Patients referred for Tc-99m MAA scintigraphy under various indications were included in this pictorial essay. Commercially available TechneScan LyoMAA cold kit from Mallinckrodt Medical B.V., Holland was used. Acquisition protocols for different indications are described in this article. Different clinical indications (e.g., pulmonary artery stenosis, hepatopulmonary syndrome, FEV1 calculation in lung surgery planning, selective internal radiation therapy planning, venography for deep venous thrombosis, left to right cardiac shunts, etc.) where Tc-99m MAA scintigraphy was asked for; how it helped in different clinical scenarios and how it can be used clinically is explained with unique and interesting case examples and images. We also reviewed the literature to look for certain remote indications of MAA imaging for the sake of completion like – (shunt scintigraphy, peritoneopleural communication, etc.) Conclusion: Tc-99m MAA is a very useful radiopharmaceutical, which can be used for many other indications apart from the commonly used indication of lung perfusion scan in pulmonary embolism. It can provide useful clinical information in other indications, which we try to highlight in this article. PMID:24250023

  6. [99mTc-HMPAO labeling of leukocytes and thrombocytes. Characteristics and diagnostic consequences].

    PubMed

    Becker, W; Börner, W

    1988-01-01

    The lipophilic complex 99mTc-hexamethylpropylene-amineoxime (HMPAO) is suitable for labelling of leukocytes and platelets in vitro. With a labelling efficiency of 35 to 70% of marked cells between 0.3 and 0.5 GBq of the 99mTc are re-injected into the patient. Problems in differential diagnosis arise particularly in lesions in the pelvis and abdomen because of the rapid renal elimination of the 99mTc complex, with accumulation in the kidneys and bladder. Two hours after injection, biliary excretion leads to intestinal activity. After 24 hours there was activity in the colon in all patients. In summary, labelling of cells with 99mTc-HMPAO provides a practical method based on an available radio nuclide which can be used as an alternative to 111In-oxine, but cannot altogether replace the latter method because of the specific properties and the short physical half-life of 99mTc. PMID:2829311

  7. 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.

  8. Imaging and Dosimetry of 99mTc EC Annexin V: Preliminary Clinical Study Targeting Apoptosis in Breast Tumors

    PubMed Central

    Kurihara, Hiroaki; Yang, David J.; Cristofanilli, Massimo; Erwin, William D.; Yu, Dong-Fang; Kohanim, Saady; Mendez, Richard; Kim, E. Edmund

    2008-01-01

    Background Early detection of cellular events is important to predict the outcome of the patients. This study was aimed to use 99mTc EC-annexin V to image tumor cells undergoing apoptosis. Methods In ten patients with breast cancer, scintigraphic images and dosimetric estimates were obtained after administering 99mTc EC-annexin V. Results Nine of the 10 cases showed detectable 99mTc EC-annexin V uptake in tumor. Higher values of T/N ratios are associated with patient after treatment. Conclusions Apoptosiscan be quantified using 99mTc EC-annexin V. PMID:18308577

  9. 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

  10. 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

  11. New brain perfusion imaging agents based on /sup 99m/Tc-bis(aminoethanethiol) complexes: stereoisomers and biodistribution

    SciTech Connect

    Kung, H.F.; Guo, Y.Z.; Yu, C.C.; Billings, J.; Subramanyam, V.; Calabrese, J.C.

    1989-02-01

    In developing new brain perfusion imaging agents, we prepared /sup 99m/Tc complexes of racemic mixtures of bis(aminoethanethiol) (BAT) derivatives containing an N'-benzylpiperazinyl (BPA) side chain. Due to the presence of a chiral center, a mixture of diastereomers (syn and anti) following chelation with the /sup 99m/Tc (no-carrier-added) was obtained. The neutral and lipid-soluble /sup 99m/Tc-BPA-BAT (/sup 99m/Tc, T1/2 = 6 h) isomers were separated. The syn and anti isomers of carrier-added 99Tc-BPA-BAT (99Tc, T1/2 = 2 x 10(5) years) were also synthesized, separated, and crystallized. The X-ray crystallography of 99Tc-BPA-BAT showed the syn and anti conformations (in relationship with the central TC(=O)N2S2 core). Despite a similarity in the partition coefficients for the two isomers, the syn isomer showed a higher in vivo brain uptake and longer brain retention in rats (2.77 and 1.08% dose/organ at 2 and 15 min) than that of the corresponding anti isomer (0.57 and 0.27% dose/organ at 2 and 15 min). This information is important and should be taken into consideration when new /sup 99m/Tc-labeled brain perfusion imaging agents are being designed.

  12. Micromechanical Circuits for Communication Transceivers Clark T.-C. Nguyen

    E-print Network

    Nguyen, Clark T.-C.

    , Michigan 48109-2122 ABSTRACT: Micromechanical (or "µmechanical) communica- tion circuits fabricated via IC generally require ceramic, SAW, or quartz acoustic resonator technologies, with Q's in excess of 1 generation, now suggest methods for board- less integration of wireless transceiver components [1]. In fact

  13. 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…

  14. Generating Decompilers

    Microsoft Academic Search

    Peter T. Breuer; Jonathan P. Bowen

    1998-01-01

    Compiler compilers are in widespread use, but decompiler compilers are a more novel concept. This paper presents an approach for the decompilation of object code back to source code using a decompiler generator. An example decompilation is presented. Potential applications include reverse engineering, quality assessment, debugging and safety-critical code validation or verification.

  15. Antilymphocyte autoantibodies generate T cell-C4d signatures in systemic lupus erythematosus.

    PubMed

    Liu, Chau-Ching; Manzi, Susan; Ahearn, Joseph M

    2014-12-01

    T cells bearing C4d, a complement activation product (CAP), have been shown to be highly sensitive and specific as diagnostic biomarkers for systemic lupus erythematosus (SLE). T cells bearing C4d are also functionally abnormal, suggesting a role for cell-bound CAPs in lupus pathogenesis. However, the mechanism responsible for generation of T-C4d has not been determined. The purpose of this cross-sectional and prospective study was to investigate the potential role of anti-T-cell autoantibodies in the generation of the T cell-bound C4d (T-C4d) signatures in SLE. Briefly, T cells from patients with SLE (n = 326), patients with other inflammatory diseases (n = 185), and healthy controls (n = 48) were characterized for surface deposition of either or both of C4d and immunoglobulin (Ig) by flow cytometry. In vitro phenotype transfer experiments were performed to characterize Ig from patients with SLE for the capacity to generate T-C4d signatures in vitro. The results demonstrate that individual patients with SLE harbor specific signatures reflecting the presence of either or both of C4d and Ig on their T cells and T-cell subsets. In addition, SLE patient-specific signatures can be transferred in vitro to normal T cells by exposure to Ig purified from the signature donor. Complement activation does not proceed through the generation of C5b-9 (membrane attack complex) or cellular lysis, and T-C4d does not correlate with lymphopenia. In conclusion, these results suggest that patient-specific T-C4d signatures are generated by anti-T-cell autoantibodies that trigger sublytic complement activation, a previously unrecognized pathway in lupus pathogenesis. PMID:25168018

  16. Subcutaneous injection of 99mTc-pertechnetate for neonatal thyroid scintigraphy.

    PubMed

    Bradford, Ray K; Tulchinsky, Mark

    2013-12-01

    A 9-day-old female infant with congenital hypothyroidism presented for thyroid scintigraphy. Multiple attempts including the "intravenous team" failed to establish peripheral access for administration of 99mTc-pertechnetate. We administered 99mTc-pertechnetate subcutaneously into the upper arm. Rapid absorption (85% of the dose in 20 minutes) was documented on dynamic images with physiological uptake, allowing diagnostic thyroid scintigraphy at 35 minutes that revealed ectopic sublingual thyroid. Subcutaneous injection allowed us to avoid traumatic and risky central vascular access procedure. When peripheral intravenous access cannot be obtained, 99mTc-pertechnetate can be administered subcutaneously for diagnostic thyroid scintigraphy, which is particularly useful in neonates. PMID:24212447

  17. Diagnosis of hepatobiliary disease in infants and children with Tc-99m-diethyl-IDA imaging

    SciTech Connect

    Ohi, R.; Klingensmith, W.C.; Lilly, J.R.

    1981-07-01

    Thirteen infants and children from 42 days to 14 years old with hepatobiliary disease underwent Tc-99m-diethyl-IDA hepatobiliary imaging. Five patients had biliary atresia, four had biliary hypoplasia, two had neonatal hepatitis, and there were single examples of alpha-1-antitrypsin deficiency and congenital hepatic fibrosis. Tc-99m-diethyl-IDA imaging accurately differentiated biliary atresia (complete bile duct obstruction) from other forms of childhood hepatobiliary disease by demonstrating no intestinal radioactivity in the former and the presence of intestinal radioactivity in the latter. In addition, two of four patients with biliary hypoplasia had nonhomogeneous parenchymal transit, and the one patient with congenital hepatic fibrosis showed possible intrahepatic cysts. In conclusion, these preliminary data indicate that Tc-99m-diethyl-IDA provides information not previously available with I-131-rose bengal; this information is likely to be useful in the noninvasive evaluation of childhood hepatobiliary disease.

  18. Photo-production of (99)Mo/(99m)Tc with electron linear accelerator beam.

    PubMed

    Avagyan, R; Avetisyan, A; Kerobyan, I; Dallakyan, R

    2014-09-01

    We report on the development of a relatively new method for the production of (99)Mo/(99m)Tc. The method involves the irradiation of natural molybdenum using high-intensity bremsstrahlung photons from the electron beam of the LUE50 linear electron accelerator located at the Yerevan Physics Institute (YerPhi). The production method has been developed and shown to be successful. The linear electron accelerator at YerPhi was upgraded to allow for significant increases of the beam intensity and spatial density. The LUE50 was also instrumented by a remote control system for ease of operation. We have developed and tested the (99m)Tc extraction from the irradiation of natural MoO3. This paper reports on the optimal conditions of our method of (99)Mo production. We show the success of this method with the production and separation of the first usable amounts of (99m)Tc. PMID:24929962

  19. Scintigraphy with 99mTc(V)-DMSA in monitoring patients with inflammatory bowel disease.

    PubMed

    Javadi, Hamid; Amiriani, Taghi; Mirkarimi, HoneySadat; Besharat, Sima; Semnani, Shahriar; Abedi, Jamshid; Seyedabadi, Mohammad; Assadi, Majid

    2013-01-01

    The clinical significance of pentavalent technetium-99m dimercaptosuccinic acid (99mTc(V)-DMSA) scintigraphy in diagnosing inflammatory bowel disease (IBD) has not yet been fully elucidated. The aim of this prospective paper was to study the above. This study included 54 patients, 22 females and 32 males (mean age: 36.68±11.49; range: 18-63 years) with IBD who came to our clinics for follow-up and were examined clinically by colonoscopy and 99mTc(V)-DMSA scintigraphy. On the follow-up studies, five patients (9.25%) relapsed, and 49 (90.74%) remained at a steady condition. There was a good correlation between the scintigraphic results and the clinical and colonoscopy data of the patients (P<0.05). In conclusion, our results indicated that 99mTc(V)DMSA scintigraphy can be complementary to colonoscopy for the diagnostic evaluation of IBD. PMID:24251309

  20. 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%.

  1. Signature of high Tc above 25 K in high quality superconducting diamond

    NASA Astrophysics Data System (ADS)

    Okazaki, Hiroyuki; Wakita, Takanori; Muro, Takayuki; Nakamura, Tetsuya; Muraoka, Yuji; Yokoya, Takayoshi; Kurihara, Shin-ichiro; Kawarada, Hiroshi; Oguchi, Tamio; Takano, Yoshihiko

    2015-02-01

    We have observed zero resistivity above 10 K and an onset of resistivity reduction at 25.2 K in a heavily B-doped diamond film. However, the effective carrier concentration is similar to that of superconducting diamond with a lower Tc. We found that the carrier has a longer mean free path and lifetime than in the previous report, indicating that this highest Tc diamond has better crystallinity compared to that of other superconducting diamond films. In addition, the susceptibility shows a small transition above 20 K in the high quality diamond, suggesting a signature of superconductivity above 20 K. These results strongly suggest that heavier carrier doped defect-free crystalline diamond could give rise to high Tc diamond.

  2. Quality control of Tc-99m DTPA for measurement of glomerular filtration: concise communication

    SciTech Connect

    Russell, C.D. (Univ. of Alabama, Birmingham); Bischoff, P.G.; Rowell, K.L.; Kontzen, F.; Lloyd, L.K.; Tauxe, W.N.; Dubovsky, E.V.

    1983-08-01

    When technetium-99m DTPA is used to measure glomerular filtration rate (GFR), the accuracy depends on the supplier of the radiopharmaceutical. The error in GFR is due to protein binding, as we have shown by direct measurement. In 19 patients, GFR measured with Tc-DTPA and corrected for protein binding agreed with that measured simultaneously using Yb-169 DTPA (correlation coefficient 0.991). Without correction, Tc-DTPA gave falsely low values in patients having good renal function, in whom unbound activity cleared rapidly while bound activity remained in the circulation. When Tc-DTPA is used to measure GFR, the in vivo protein binding should be measured and used to correct the data.

  3. 99Tc and Re incorporated into metal oxide polyoxometalates: oxidation state stability elucidated by electrochemistry and theory.

    PubMed

    McGregor, Donna; Burton-Pye, Benjamin P; Mbomekalle, Israel M; Aparicio, Pablo A; Romo, Susanna; López, Xavier; Poblet, Josep M; Francesconi, Lynn C

    2012-08-20

    The radioactive element technetium-99 ((99)Tc, half-life = 2.1 × 10(5) years, ?(-) of 253 keV), is a major byproduct of (235)U fission in the nuclear fuel cycle. (99)Tc is also found in radioactive waste tanks and in the environment at National Lab sites and fuel reprocessing centers. Separation and storage of the long-lived (99)Tc in an appropriate and stable waste-form is an important issue that needs to be addressed. Considering metal oxide solid-state materials as potential storage matrixes for Tc, we are examining the redox speciation of Tc on the molecular level using polyoxometalates (POMs) as models. In this study we investigate the electrochemistry of Tc complexes of the monovacant Wells-Dawson isomers, ?(1)-P(2)W(17)O(61)(10-) (?1) and ?(2)-P(2)W(17)O(61)(10-) (?2) to identify features of metal oxide materials that can stabilize the immobile Tc(IV) oxidation state accessed from the synthesized Tc(V)O species and to interrogate other possible oxidation states available to Tc within these materials. The experimental results are consistent with density functional theory (DFT) calculations. Electrochemistry of K(7-n)H(n)[Tc(V)O(?(1)-P(2)W(17)O(61))] (Tc(V)O-?1), K(7-n)H(n)[Tc(V)O(?(2)-P(2)W(17)O(61))] (Tc(V)O-?2) and their rhenium analogues as a function of pH show that the Tc-containing derivatives are always more readily reduced than their Re analogues. Both Tc and Re are reduced more readily in the lacunary ?1 site as compared to the ?2 site. The DFT calculations elucidate that the highest oxidation state attainable for Re is VII while, under the same electrochemistry conditions, the highest oxidation state for Tc is VI. The M(V)? M(IV) reduction processes for Tc(V)O-?1 are not pH dependent or only slightly pH dependent suggesting that protonation does not accompany reduction of this species unlike the M(V)O-?2 (M = (99)Tc, Re) and Re(V)O-?1 where M(V/IV) reduction process must occur hand in hand with protonation of the terminal M?O to make the ?*(M?O) orbitals accessible to the addition of electrons. This result is consistent with previous extended X-ray absorption fine structure (EXAFS) and X-ray absorption near edge structure (XANES) data that reveal that the Tc(V) is "pulled" into the -?1 framework and that may facilitate the reduction of Tc(V)O-?1 and stabilize lower Tc oxidation states. This study highlights the inequivalency of the two sites, and their impact on the chemical properties of the Tc substituted in these positions. PMID:22839965

  4. Evaluation of 99mTcN-MPO as a New Myocardial Perfusion Imaging Agent in Normal Dogs and in an Acute Myocardial Infarction Canine Model: Comparison with 99mTc-Sestamibi

    PubMed Central

    Bu, Lihong; Li, Renfei; Jin, Zhongnan; Wen, Xiaofei; Liu, Shuang; Yang, Baofeng; Shen, Baozhong; Chen, Xiaoyuan

    2010-01-01

    Purpose 99mTcN-MPO ([99mTcN(mpo)(PNP5)]+: mpo=2-mercaptopyridine oxide and PNP5=N-ethoxyethyl-N,N-bis[2-(bis(3-methoxypropyl)phosphino)ethyl]amine) is a cationic 99mTc-nitrido complex, which has favorable biodistribution and myocardial uptake with rapid liver clearance in Sprague Dawley rats. The objective of this study was to compare the biodistribution and pharmacokinetics of 99mTcN-MPO and 99mTc-Sestamibi in normal dogs, and to evaluate the potential of 99mTcN-MPO as a myocardial perfusion agent in canines with acute myocardial infarction. Methods Five normal mongrel dogs were injected intravenously with 99mTcN-MPO. Venous blood samples were collected via a femoral vein catheter at 0.5, 1, 2, 3, 4, 5, 10, 20, 30, 40, 60, and 90 min post-injection (p.i.). Anterior-posterior planar images were acquired by ?-camera at 10, 20, 30, 60, 90, and 120 min p.i. Regions of interest (ROIs) were drawn around the heart, liver, and lungs. The heart/liver and heart/lung ratios were calculated by dividing the mean counts in heart ROI by the mean counts in the liver and lung ROI, respectively. For comparison, 99mTc-sestamibi was also evaluated in the same five dogs. The interval period between the two examinations was 1 week to eliminate possible interference between these two radiotracers. In addition, single positron emission computed tomography (SPECT) images in the canine infarct model were collected 24 h after myocardial infarction at 30 and 60 min after the administration of 99mTcN-MPO (n=4) or 99mTc-Sestamibi (n=4). Results It was found that 99mTcN-MPO and 99mTc-Sestamibi displayed very similar blood clearance characteristics during the first 90 min p.i. Both 99mTcN-MPO and 99mTc-Sestamibi had a rapid blood clearance with less than 50% of initial radioactivity remaining at 1 min and less than 5% at 30 min p.i. 99mTcN-MPO and 99mTc-Sestamibi both showed good heart/lung contrast. The heart/liver ratio of 99mTcN-MPO increased with time (0.53±0.06 at 10 min, 0.90±0.062 at 30 min, and 1.22±0.06 at 60 min p.i.), whereas the heart/liver ratio of 99mTc-Sestamibi remained low at all time points (0.50±0.03 at 10 min, 0.64±0.03 at 30 min, and 0.60±0.02 at 60 min p.i.). SPECT imaging studies in canines with acute myocardial infarction indicated that good visualization of the left ventricular wall and perfusion defects could be achieved at 30 min after administration of 99mTcN-MPO but not after 99mTc-Sestamibi. Conclusion The combination of reasonable heart uptake with rapid hepatobiliary excretion makes 99mTcN-MPO a promising new radiotracer for myocardial perfusion imaging. PMID:20458635

  5. Radiochemical studies of 99mTc complexes of modified cysteine ligands and bifunctional chelating agents.

    PubMed

    Pillai, M R; Kothari, K; Banerjee, S; Samuel, G; Suresh, M; Sarma, H D; Jurisson, S

    1999-07-01

    The synthesis of four novel ligands using the amino-acid cysteine and its ethyl carboxylate derivative is described. The synthetic method involves a two-step procedure, wherein the intermediate Schiff base formed by the condensation of the amino group of the cysteine substrate and salicylaldehyde is reduced to give the target ligands. The intermediates and the final products were characterized by high resolution nuclear magnetic resonance spectroscopy. Complexation studies of the ligands with 99mTc were optimized using stannous tartrate as the reducing agent under varying reaction conditions. The complexes were characterized using standard quality control techniques such as thin layer chromatography, paper electrophoresis, and paper chromatography. Lipophilicities of the complexes were estimated by solvent extraction into chloroform. Substantial changes in net charge and lipophilicity of the 99mTc complexes were observed on substituting the carboxylic acid functionality in ligands I and II with the ethyl carboxylate groups (ligands II and IV). All the ligands formed 99mTc complexes in high yield. Whereas the complexes with ligands I and II were observed to be hydrophilic in nature and not extractable into CHCl3, ligands III and IV resulted in neutral and lipophilic 99mTc complexes. The 99mTc complex with ligand II was not stable and on storage formed a hydrophilic and nonextractable species. The biodistribution of the complexes of ligands I and II showed that they cleared predominantly through the kidneys, whereas the complexes with ligands III and IV were excreted primarily through the hepatobiliary system. No significant brain uptake was observed with the 99mTc complexes with ligands III and IV despite their favorable properties of neutrality, lipophilicity, and conversion into a hydrophilic species. These ligands offer potential for use as bifunctional chelating agents. PMID:10473195

  6. 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.

  7. A novel approach to infection imaging using a synthetic Tc-99m-labeled leukotactic peptide

    SciTech Connect

    Som, P.; Oster, Z.H.; Sharma, S. [Brookhaven National Lab., Upton, NY (United States)]|[State Univ. of New York, Stony Brook, NY (United States)]|[Rhomed, Inc., Albuquerque, NM (United States)] [and others

    1996-05-01

    RMT1, a synthetic peptide binding to PMN and macrophage receptors was labeled with Tc-99m and investigated as a potential imaging agent for abscess and inflammation. Experimental abscesses were induced in rabbits and dogs by turpentine and E.coli injection. After injection of Tc-99m-RMT1 two and twelve day old abscesses were visualized within 20 min. In initial studies, a dose of 30 {mu}g of peptide/3 mCi was used. This amount was subsequently reduced to 1.5 {mu}g peptide with same amount of Tc-99m yielding similar imaging results. Technetium-99m-IgG and Tc-99m-MAG-3 were used as positive and negative controls, respectively. After injection of IgG abscesses were visualized but activity in blood was always higher than in abscess. When using Tc-99m RMT1 rapid abscess visualization and faster blood clearance was observed. The accumulation of RMT1 was monophasic, i.e., following the initial visualization, activity continued to build up continuously for 1{1/2} hr. Tc-99m-MAG3 accumulated initially in abscess, but activity washed out. In dogs, RMT1 blood clearance showed three components: a fast component with t{1/2}=1.9 min, 73%, intermediate t{1/2}=22 min, 24.5% and slow component, t{1/2}=115, 9.5% with 3 hours cumulative urine excretion of 40-51%. RMT1 appears to be more advantageous than currently available methods because of rapidity of imaging, simpler preparation before injection and will probably be less expensive and time consuming compared to labeled WBC. These results indicate that clinical experiments are warranted.

  8. 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.

  9. Combined folate gene MTHFD and TC polymorphisms as maternal risk factors for Down syndrome in China.

    PubMed

    Liao, Y P; Zhang, D; Zhou, W; Meng, F M; Bao, M S; Xiang, P; Liu, C Q

    2014-01-01

    We examined whether polymorphisms in the methylenetetrahydrofolate dehydrogenase (MTHFD) and transcobalamin (TC) genes, which are involved in folate metabolism, affect maternal risk for Down syndrome. We investigated 76 Down syndrome mothers and 115 control mothers from Bengbu, China. Genomic DNA was isolated from the peripheral lymphocytes. Polymerase chain reaction and restriction fragment length polymorphism were used to examine the polymorphisms of MTHFD G1958A and TC C776G. The frequencies of the polymorphic alleles were 24.3 and 19.1% for MTHFD 1958A, 53.9 and 54.2% for TC 776G, in the case and control groups, respectively. No significant differences were found between two groups in relation to either the allele or the genotype frequency for both polymorphisms. However, when gene-gene interactions between these two polymorphisms together with previous studied C677T and A1298C polymorphisms in the methylenetetrahydrofolate reductase (MTHFR) gene were analyzed, the combined MTHFR 677CT/TT and MTHFD 1958AA/GA genotype was found to be significantly associated with the risk of having a Down syndrome child [odds ratio (OR) = 3.11; 95% confidence interval (95%CI) = 1.07-9.02]. In addition, the combined TC 776CG and MTHFR 677TT genotype increased the risk of having a child with Down syndrome 3.64-fold (OR = 3.64; 95%CI = 1.28-10.31). In conclusion, neither MTHFD G1958A nor TC C776G polymorphisms are an independent risk factor for Down syndrome. However, the combined MTHFD/MTHFR, TC/MTHFR genotypes play a role in the risk of bearing a Down syndrome child in the Chinese population. PMID:24668664

  10. Unilateral Tc-99m pertechnetate breast uptake: is it always benign?

    PubMed

    Tiktinsky, Ekaterina; Horne, Tifha; Agranovich, Svetlana; Landsberg, Sophie

    2007-09-01

    Although the thyroid gland is the principal organ with the ability to concentrate iodide and take up Tc-99m pertechnetate, other tissues such as choroid plexus, salivary glands, mucoid cells of stomach, and lactating breast tissue also possess this property. The lactating mammary gland can concentrate iodide, which mediated by sodium/iodine symporter (NIS) is actively transported and secreted in the milk, to supply iodide to the newborn for the biosynthesis of thyroid hormones. The authors present an uncommon case of unilateral Tc-99m breast uptake in a breast-feeding woman. PMID:17710032

  11. Is the relative 99m Tc-DMSA clearance a useful marker of proximal tubular dysfunction?

    Microsoft Academic Search

    W. H. J. Luijk; G. J. Ensing; S. Meijer; A. J. M. Donker; D. A. Piers

    1984-01-01

    The clearance of125I-sodium iothalamate,131I-sodium hippurate,99mTc-DMSA, and ß2-microglobulin were determined in 20 patients with proven or suspected proximal tubular dysfunction and in 18 control patients with various renal diseases. A clear distinction in the relative99mTc-DMSA clearance was observed between patients with proximal tubulopathy (14%–35%) and control patients (>14%). A similar difference between the two groups was found in the relative ß2-microglobulin

  12. Unusual Tc-99m MDP and I-123 MIBG images in focal pyelonephritis

    SciTech Connect

    Jacobs, A.; Lenoir, P.; Delree, M.; Ramet, J.; Piepsz, A. (Vrije Universiteit, Brussel (Belgium))

    1990-11-01

    A 6-year-old boy presented with an inflammatory syndrome. Because Tc-99m MDP bone scintigraphy revealed increased tracer uptake at the upper pole of the right kidney, further studies were oriented towards a diagnosis of renal or adrenal pathology. I-123 metaiodobenzylguanidine (MIBG) accumulated at the site of the abnormal MDP uptake. The diagnosis of neuroblastoma or allied disorder was excluded on the basis of other investigations and further evaluation, suggesting that the MIBG uptake was a false-positive. Findings on clinical imaging, laboratory findings, Tc-99m DMSA imaging, sonography, and CT scanning were highly suggestive of acute focal pyelonephritis.

  13. 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.

  14. Synchronous thoracic and abdominal enteric duplication cysts: Accurate detection with 99mTc-pertechnetate scintigraphy

    PubMed Central

    Kumar, Kunal; Dhull, Varun Singh; Karunanithi, Sellam; Chakraborty, Partha Sarathi; Roy, Shambo Guha; Ghosh, Shouriyo; Agarwala, Sandeep; Tripathi, Madhavi

    2015-01-01

    Enteric duplication cysts (EDCs) are uncommon congenital anomalies, which can occur anywhere along the gastrointestinal tract and vary greatly in presentation, size, location and symptoms. Ectopic gastric mucosa is reported to be found in 20-30% of these duplications. 99mTc-pertechnetate scintigraphy is a useful modality for preoperative localization of the ectopic functioning gastric mucosa in the EDCs. We report a case where 99mTc-pertechnetate scintigraphy was useful in detecting synchronous thoracic and abdominal duplication cysts with functioning gastric mucosa thus having an impact on the patient management. PMID:25589809

  15. Synchronous thoracic and abdominal enteric duplication cysts: Accurate detection with (99m)Tc-pertechnetate scintigraphy.

    PubMed

    Kumar, Kunal; Dhull, Varun Singh; Karunanithi, Sellam; Chakraborty, Partha Sarathi; Roy, Shambo Guha; Ghosh, Shouriyo; Agarwala, Sandeep; Tripathi, Madhavi

    2015-01-01

    Enteric duplication cysts (EDCs) are uncommon congenital anomalies, which can occur anywhere along the gastrointestinal tract and vary greatly in presentation, size, location and symptoms. Ectopic gastric mucosa is reported to be found in 20-30% of these duplications. (99m)Tc-pertechnetate scintigraphy is a useful modality for preoperative localization of the ectopic functioning gastric mucosa in the EDCs. We report a case where (99m)Tc-pertechnetate scintigraphy was useful in detecting synchronous thoracic and abdominal duplication cysts with functioning gastric mucosa thus having an impact on the patient management. PMID:25589809

  16. 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.

  17. Origins of low- and high-pressure discontinuities of $T_{c}$ in niobium

    Microsoft Academic Search

    Stefano de Gironcoli; Paolo Giannozzi; CNR-INFM DEMOCRITOS

    2005-01-01

    The discontinuities of $T_{c}$ in Niobium under pressure are examined by\\u000ameans of the pseudopotential plane-wave implementation of the electron-phonon\\u000acoupling calculated from density-functional perturbation theory. Both low- and\\u000ahigh-pressure discontinuities of $T_{c}$ have their origin in the Kohn\\u000aanomalies and are caused by the low-frequency phonons, but the mechanism\\u000aleading to the discontinuities is different in the two cases.

  18. Role of histamine H3 receptor in glucagon-secreting ?TC1.6 cells

    PubMed Central

    Nakamura, Tadaho; Yoshikawa, Takeo; Naganuma, Fumito; Mohsen, Attayeb; Iida, Tomomitsu; Miura, Yamato; Sugawara, Akira; Yanai, Kazuhiko

    2014-01-01

    Pancreatic ?-cells secrete glucagon to maintain energy homeostasis. Although histamine has an important role in energy homeostasis, the expression and function of histamine receptors in pancreatic ?-cells remains unknown. We found that the histamine H3 receptor (H3R) was expressed in mouse pancreatic ?-cells and ?TC1.6 cells, a mouse pancreatic ?-cell line. H3R inhibited glucagon secretion from ?TC1.6 cells by inhibiting an increase in intracellular Ca2+ concentration. We also found that immepip, a selective H3R agonist, decreased serum glucagon concentration in rats. These results suggest that H3R modulates glucagon secretion from pancreatic ?-cells. PMID:25685663

  19. Theoretical Study of the Chemical Pressure Effect on Tc in the Cuprate Superconductors

    NASA Astrophysics Data System (ADS)

    Sakakibara, H.; Suzuki, K.; Usui, H.; Kuroki, K.; Arita, R.; Aoki, H.

    Application of physical pressure on the cuprate superconductors often results in an enhancement of Tc. Motivated by this fact, we study the chemical pressure effect on the single-layered La2CuO4 and HgBa2CuO4 starting from the two-orbital Hubbard model deduced from a first-principles calculation. It is shown that the chemical pressure effects induced by La-site substitution in La2CuO4 or Hg-site substitution in HgBa2CuO4 are not expected to be effective for raising Tc.

  20. 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.

  1. Tc-99m sulfur colloid scanning in blunt trauma: detection of abdominal bleeding

    SciTech Connect

    Bronfman, H.J.; Kunkel, B.K.; Rabin, H.S.

    1981-11-01

    Tc-99m sulfur colloid scintigraphy can detect and locate active lower gastrointestinal bleeding. The same principles apply to the detection and location of active intra-abdominal or pelvic hemorrhage following blunt abdominal trauma. We report two patients with abdominal bleeding who were correctly diagnosed by this method. As part of the routine examination of all patients having Tc-99m sulfur colloid liver-spleen scans for trauma, 500,000-count images should be made of the rest of the abdomen and pelvis.

  2. Polarons and Bipolarons in High-Tc Superconductors and Related Materials

    NASA Astrophysics Data System (ADS)

    Salje, E. K. H.; Alexandrov, A. S.; Liang, W. Y.

    2005-07-01

    1. A polaron theory of high temperature superconductors; 2. On the possibility of non-BCS superconductivity; 3. Bipolaron Bose-liquid in high-Tc superconductors; 4. Spin polarons in high-Tc superconductors; 5. The polaron scenario for high-Tc superconductors; 6. Formation, phase separation and superconductivity of large bipolarons; 7. Polarons and bipolarons in WO3-x YBa2Cu3O7; 8. Polaron bands in the far- and mid-infrared spectra of e-doped cuprates; 9. Electron-phonon interaction of non-equilibrium carriers in the photoinduced state of YBa2Cu3O7-d; 10. Experimental evidence of local lattice distortion in superconducting oxides; 11. Hall effect due to small polarons and conduction in narrow energy bands; 12. Static and dynamic conductivity of untwinned YBa2Cu4O8: gaps or condensation?; 13. The near infrared and optical absorption of high-Tc superconductors using powders; 13a. Polaronic theory of mid-infrared conductivity: a numerical cluster study; 14. Electromagnetic properties of local pair superconductors; 15. Electron-hole asymmetric polarons; 16. On the nature of the superconducting state in high-Tc cuprates; 17. High-Tc superconductivity with polarons and bipolarons: an approach from the insulating states; 18. Coexistence of small polaron and Anderson localisation in high-Tc superconducting materials; 19. Concentration and temperature dependence of magnetic polaron spectra in the t-J model; 20. Mass enhancement without band-narrowing in t-t'-J related models: predictions for Fermi-surface and optical conductivity; 21. Polarons in Peierls-Hubbard models; 22. Exact estimates of inter-polaron coupling constants resulting in bipolaron formation; 23. Coulomb interaction and the criteria for bipolaron formation; 24. Large bipolarons and high-Tc materials; 25. Collective excitations in the ground state of a two-dimensional attractive Fermi gas; 26. Strong two-band electron trapping, state hybridization effects and related pressure induced phenomena in semiconductors; 26a. Bismuth disproportionation in super and semiconducting barium bismuthates; 27. Magnetic polarons in concentrated and diluted magnetic semiconductors; 28. Energy scales of exotic superconductors.

  3. [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

  4. 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.

  5. Hydroelectric Generator

    NASA Astrophysics Data System (ADS)

    Zipprian, Daniel

    2012-03-01

    The idea behind a hydro electric generator is to have a large potential well of water that you can be controlled to be able to convert into kinetic energy. The kinetic energy is from the flow of water which is directed towards some kind of turbine. In turn the kinetic energy is turned into mechanical energy. The turning of the turbine rotates the rotor part of the generator, and the stator remains stationary. Induction is caused when the rotor is rotating around the stator. This is caused when a magnetic field interacts with a wire causing the electrons inside the wire to face in the same direction. Once the magnetic field begins to move the electrons start to flow through the wire creating current. For this to work the direction of the magnetic field has to be perpendicular to the direction of the coils of wires. For my design I plan to funnel the flow of water into a nozzle which will be aimed towards my turbine. The turbine with be connected to a shaft that will be connected to my rotor. The rotor I designed uses a brake router for the surface to hold me magnets. The system will be vertical, with the rotor as the highest part on the generator and the turbine at the bottom. The magnets will be facing downwards with the magnetic field going in a vertical direction. The stator of my generator will be the coils which will sit on top of a metal ring that have the ability to rise or low to match the height of the brake router.

  6. Hydroelectric generator

    Microsoft Academic Search

    Vauthier

    1980-01-01

    The efficiency of a hydro-electric generator is improved by providing open-ended hollow tubes having influx ends proximate the axis and efflux ends proximate the periphery of a fan-bladed turbine. The jets of water developed by rotation of the fanbladed turbine are directed against turbine vanes at the periphery of the fan blades. The device is particularly suitable for mounting in

  7. 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.

  8. 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

  9. Cu-Free 1,3-Dipolar Cycloaddition Click Reactions To Form Isoxazole Linkers in Chelating Ligands for fac-[MI(CO)3]+ Centers (M = Re, 99mTc)

    PubMed Central

    2015-01-01

    Isoxazole ring formation was examined as a potential Cu-free alternative click reaction to CuI-catalyzed alkyne/azide cycloaddition. The isoxazole reaction was explored at macroscopic and radiotracer concentrations with the fac-[MI(CO)3]+ (M = Re, 99mTc) core for use as a noncoordinating linker strategy between covalently linked molecules. Two click assembly methods (click, then chelate and chelate, then click) were examined to determine the feasibility of isoxazole ring formation with either alkyne-functionalized tridentate chelates or their respective fac-[MI(CO)3]+ complexes with a model nitrile oxide generator. Macroscale experiments, alkyne-functionalized chelates, or Re complexes indicate facile formation of the isoxazole ring. 99mTc experiments demonstrate efficient radiolabeling with click, then chelate; however, the chelate, then click approach led to faster product formation, but lower yields compared to the Re analogues. PMID:24483834

  10. Cu-free 1,3-dipolar cycloaddition click reactions to form isoxazole linkers in chelating ligands for fac-[M(I)(CO)3]+ centers (M = Re, 99mTc).

    PubMed

    Bottorff, Shalina C; Kasten, Benjamin B; Stojakovic, Jelena; Moore, Adam L; MacGillivray, Leonard R; Benny, Paul D

    2014-02-17

    Isoxazole ring formation was examined as a potential Cu-free alternative click reaction to Cu(I)-catalyzed alkyne/azide cycloaddition. The isoxazole reaction was explored at macroscopic and radiotracer concentrations with the fac-[M(I)(CO)3](+) (M = Re, (99m)Tc) core for use as a noncoordinating linker strategy between covalently linked molecules. Two click assembly methods (click, then chelate and chelate, then click) were examined to determine the feasibility of isoxazole ring formation with either alkyne-functionalized tridentate chelates or their respective fac-[M(I)(CO)3](+) complexes with a model nitrile oxide generator. Macroscale experiments, alkyne-functionalized chelates, or Re complexes indicate facile formation of the isoxazole ring. (99m)Tc experiments demonstrate efficient radiolabeling with click, then chelate; however, the chelate, then click approach led to faster product formation, but lower yields compared to the Re analogues. PMID:24483834

  11. 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

  12. Immunoassay 014. Hammock BD, Sparks TC, Mumby SM (1977) Selective inhibition of JH esterases from cockroach hemolymph.

    E-print Network

    Ferrara, Katherine W.

    1977-01-01

    Immunoassay 014. Hammock BD, Sparks TC, Mumby SM (1977) Selective inhibition of JH esterases from cockroach hemolymph. Pestoc Biochem Physiol 7:517­530 015. Hammock BD, Kuwano E, Ketterman A, Scheffrahn RH. 26(1):166­170 016. Hammock BD, Sparks TC (1977) A rapid assay for insect juvenile hormone esterase

  13. Novel cyclopentadienyl tricarbonyl (99m)tc complexes containing 1-piperonylpiperazine moiety: potential imaging probes for sigma-1 receptors.

    PubMed

    Wang, Xia; Li, Dan; Deuther-Conrad, Winnie; Lu, Jie; Xie, Ying; Jia, Bing; Cui, Mengchao; Steinbach, Jörg; Brust, Peter; Liu, Boli; Jia, Hongmei

    2014-08-28

    We report the design, synthesis, and evaluation of a series of novel cyclopentadienyl tricarbonyl (99m)Tc complexes as potent ?1 receptor radioligands. Rhenium compounds 3-(4-(1,3-benzodioxol-5-ylmethyl)piperazin-1-yl)propylcarbonylcyclopentadienyl tricarbonyl rhenium (10a) and 4-(4-(1,3-benzodioxol-5-ylmethyl)piperazin-1-yl)butylcarbonylcyclopentadienyl tricarbonyl rhenium (10b) possessed high in vitro affinity for ?1 receptors and moderate to high selectivity for ?2 receptors and the vesicular acetylcholine transporter. Biodistribution studies in mice demonstrated high initial brain uptake for corresponding (99m)Tc derivatives [(99m)Tc]23 and [(99m)Tc]24 of 2.94 and 2.13% injected dose (ID)/g, respectively, at 2 min postinjection. Pretreatment of haloperidol significantly reduced the radiotracer accumulation of [(99m)Tc]23 or [(99m)Tc]24 in the brain. Studies of the cellular uptake of [(99m)Tc]23 in C6 and DU145 tumor cells demonstrated a reduction of accumulation by incubation with haloperidol, 1-(3,4-dimethoxyphenethyl)-4-(3-phenylpropyl)piperazine (SA4503), or 1,3-di-o-tolyl-guanidine (DTG). Furthermore, blocking studies in C6 glioma-bearing mice confirmed the specific binding of [(99m)Tc]23 to ?1 receptors in the tumor. PMID:25073047

  14. Lung uptake on Tc-99m albumin colloid liver spleen scan and on Ga-67 scan in angiotropic lymphoma

    SciTech Connect

    Kacki, M.H.; Joyce, J.M.; Coupal, J.J.; Ryo, U.Y. (Univ. of Kentucky Medical Center, Lexington (USA))

    1990-03-01

    Lung uptake of Tc-99m sulfur colloid has been reported in various hepatic and extrahepatic diseases, and lung uptake of gallium-67 may occur in patients with various interstitial lung disease without radiographic abnormality. This may be the first case of Tc-99m albumin colloid and Ga-67 lung uptake in a patient with angiotropic lymphoma of the liver, spleen, and uterus.

  15. Localization of skeletal-imaging 99mTc chelates in dead cells in tissue culture: concise communication.

    PubMed

    Dewanjee, M K

    1976-11-01

    Screening new agents for imaging myocardial infarcts and investigating the mechanism of cellular uptake and subcellular localization of these agents prompted us to develop a necrosis model in tissue culture. Live cells obtained from exponentially growing cultures and dead cells obtained from nutritionally depleted plateau-phase cultures were incubated with 99mTc-pyrophosphate, 99mTc-hydroxyethylene diphosphonate (99mTc-HEDP), 67Ga-citrate, and 45Ca-HEDP. For the bone-seeking 99mTc chelates, the ratio of dead to live cell radioactivity was 15--20 after 1 hr of incubation. On the other hand, no preferential binding of 67Ga-citrate was observed, indicating that the mechanism of 67Ga localization in infarcts is different from that of the 99mTc chelates. The death cells accumulated only twice as much 45Ca-HEDP or 45Ca-pyrophosphate as did live cells, possibly due to the carrier effect of calcium in the medium. The receptors for 99mTc chelates could be partially blocked by preincubating the dead cells with microgram amounts of Na-HEDP. Heat-denaturation of live cells also increased the localization of 99mTc-HEDP in the cells, and this uptake was proportional to the duration of heating. Bone-seeking 99mTc chelates could be used for marking dead cells instead of conventional staining methods. PMID:978263

  16. S.N. Gerasimov, T.C. Hender, J. Morris, V. Riccardo, L.E. Zakharov and JET EFDA contributors

    E-print Network

    S.N. Gerasimov, T.C. Hender, J. Morris, V. Riccardo, L.E. Zakharov and JET EFDA contributors CCFE in JET S.N. Gerasimov 1 , T.C. Hender 1 , J. Morris 1 , V. Riccardo 1 , L.E. Zakharov 2 and JET EFDA.073009 Plasma current asymmetries during disruptions in JET Gerasimov S N, Hender T C, Morris J, Riccardo

  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. 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.

  19. Hypertension in children. Increased efficacy of technetium Tc/sup 99m/ succimer in screening for renal disease

    SciTech Connect

    Rosen, P.R.; Treves, S.; Ingelfinger, J.

    1985-02-01

    Renal scintigraphy with technetium Tc-99m succimer (DMSA) and technetium Tc-99m pentetate (DTPA) was used to study 80 hypertensive pediatric and adolescent patients. Renal abnormalities such as asymmetry of function, size, or shape were identified in 13 patients. Both excretory urography and technetium Tc-99m pentetate studies were successful in detecting 54% of the abnormalities in patients studied; technetium Tc-99m succimer identified 92%. The accuracy of the latter was 96%, with a specificity of 97%. The ability of technetium Tc-99m succimer renal scintigraphy to identify accurately the presence or absence of renal abnormalities warrants its inclusion in the initial examination of pediatric and adolescent patients with hypertension.

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

    SciTech Connect

    Post, Debra S. (Sandia National Laboratories, Livermore, CA); 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.

  1. Detection of gastrointestinal blood loss with /sup 99m/Tc-labeled, heat-treated red blood cells

    SciTech Connect

    Som, P. (Brookhaven National Lab., Upton, NY); Oster, Z.H.; Atkins, H.L.; Goldman, A.G.; Sacker, D.F.; Harold, W.H.; Fairchild, R.G.; Richards, P.; Brill, A.B.

    1981-01-01

    Studies in dogs showed that heat-treated /sup 99m/Tc-labeled red blood cells (HT/RBC) afford a highly sensitive means of detecting gastrointestinal bleeding as low as 0.12 ml/min, which could not be seen with unheated /sup 99m/Tc-RBC, /sup 99m/Tc-sulfur colloid, or /sup 99m/Tc-DTPA. In addition, as the right upper quadrant and epigastrium remained free of activity, only one fifth to one tenth of the dose of /sup 99m/Tc was needed. The safety of HT/RBC in humans has been documented, and the experiments in dogs suggest that it may have advantages over other agents in detecting gastrointestinal bleeding.

  2. Detection of gastrointestinal blood loss with 99mTc-labeled, heat-treated red blood cells. [Dogs

    SciTech Connect

    Som, P.; Oster, Z.H. Atkins, H.L.; Goldman, A.G.; Sacker, D.F.; Harold, W.H.; Fairchild, R.G.; Richards, P.; Brill, A.B.

    1981-01-01

    Studies in dogs showed that heat-treated 99mTc-labeled red blood cells (HT/RBC) afford a highly sensitive means of detecting gastrointetinal bleeding as low as 0.12 ml/min., which could not be seen with unheated 99mTc-RBC, 99mTc-sulfur colloid, or 99mTc-DTPA. In addition, as the right upper quadrant and epigastrium remained free of activity, only one fifth to one tenth of the dose of 99mTc was needed. The safety of HT/RBC in humans has been documented, and the experiments in dogs suggest that it may have advantages over other agents in detecting gastrointestinal bleeding.

  3. Extrathyroidal uptake from thyroid carcinoma on 99mTc-pertechnetate scintigraphy.

    PubMed

    Khan, Sami U; Khan, Aakif U; Khan, Ayub; Shah, Abdul Saeed; Khan, Kamran

    2011-12-01

    Three cases of imaging with 99mTc-pertechnetate (99mTcO4) and unusual positive lymph node uptake in the neck are reported hereby. Two cases were later diagnosed to be well-differentiated thyroid carcinoma, (DTC) with nodal metastasis. The third was a confirmed case of carcinoma thyroid that had presented with mass in the neck soon after surgery, being prepared for ablative dose of radioactive iodine (131I). All three were young females under 40 years of age. These 3 cases signify that extra thyroidal areas of uptake on a routine thyroid scan with 99mTcO4 can some time be due to thyroid carcinoma with regional metastases. Foci of metastasis in patients with DTC may be incidentlly detected with 99mTcO4 scan. Multinodular goiter with palpable lymph node should always be investigated for exclusion of malignancy. The patients underwent near total thyroidectomy and radical neck dissection; histopathology confirmed the scan findings. PMID:22166703

  4. Changes in biodistribution of radiopharmaceuticals due to impurities - Tc-99m radiopharmaceuticals

    SciTech Connect

    Yokoyama, A.; Horiuchi, K.

    1981-06-01

    In this review the influence of impurities in RP such as Tc-99m complexes of bleomycin, pyridoxylidene-glutamate, DMSA, phosphate derivatives, and Ga-67 citrate will be further discussed from the point of view of their preparation as a way to understanding the labeling reaction of the useful form of a given RP.

  5. Tc-99m DMSA renal uptake: influence of biochemical and physiologic factors

    SciTech Connect

    Yee, C.A.; Lee, H.B.; Blaufox, M.D.

    1981-12-01

    Thirty-eight female Sprague-Dawley rats were studied to determine the effects of (a) tubular blockade and (b) commonly encountered changes in hydration and acid-base balance, on the urinary excretion and renal localization of Tc-99m dimercaptosuccinic acid (DMSA). Ten additional rats were studied to quantitate the in vivo protein binding of Tc-99m DMSA, and a final group of 12 animals was used to quantitate DMSA distribution in animals with diminished functional renal mass. Both osmotic diuresis and dehydration by water deprivation for 24 hr resulted in a plasma clearance of DMSA slower than in control animals. Acid-base imbalances significantly affected the renal accumulation of DMSA, and acidosis was associated with markedly increased background due to increased liver accumulation. The protein-bound portion of Tc-99m DMSA in the plasma was high, reaching 89% within the first 5 min, and rising very slightly (n.s.) with time. The unbound portion of DMSA had a plasma clearance slightly higher than the GFR. Ablation of large amounts of renal tissue, resulting in significant decreases in GFR, did not significantly affect the renal localization of DMSA in the intact portions of the kidneys. These data demonstrate that commonly encountered changes in acid-base balance and hydration will significantly alter the biologic distribution of Tc-99m DMSA. These factors should be controlled when carrying out clinical studies.

  6. 99mTc dimercaptosuccinic acid (DMSA) scan as first investigation of urinary tract infection

    Microsoft Academic Search

    I G Verber; M R Strudley; S T Meller

    1988-01-01

    A total of 115 children under 5 years who presented with a first symptomatic urinary tract infection and who had a 99mTc dimercaptosuccinic acid (DMSA) scan were studied to assess its value and compare the findings with those of other imaging techniques. Renal cortical defects were detected in 65 kidneys by DMSA scan, intravenous urogram, and ultrasound scan combined; 62

  7. 99mTc dimercaptosuccinic acid (DMSA) scan in patients with established radiological renal scarring

    Microsoft Academic Search

    J M Smellie; P J Shaw; N P Prescod; H M Bantock

    1988-01-01

    The findings on 99mTc dimercaptosuccinic acid (DMSA) scans were examined in 54 patients aged 3 to 33 years in whom renal scarring had been diagnosed radiologically in childhood after urinary tract infection. There was no recent history of infection. Vesicoureteric reflux had been present in 48 patients and had stopped in 23 at the time of the DMSA scan. In

  8. 99mTc DMSA renal uptake: influence of biochemical and physiologic factors

    SciTech Connect

    Yee, C.A.; Lee, H.B.; Blaufox, M.D.

    1981-12-01

    Thirty-eight female Sprague-Dawley rats were studied to determine the effects of (a) tubular blockade and (b) commonly encountered changes in hydration and acid-base balance, on the urinary excretion and renal localization of 99mTc dimercaptosuccinic acid (DMSA). Ten additional rats were studied to quantitate the in vivo protein binding of 99mTc DMSA, and a final group of 12 animals was used to quantitate DMSA distribution in animals with diminished functional renal mass. Both osmotic diuresis and dehydration by water deprivation for 24 hr resulted in a plasma clearance of DMSA slower than in control animals. Acid-base imbalances significantly affected the renal accumulation of DMSA, and acidosis was associated with markedly increased background due to increased liver accumulation. The protein-bound portion of 99mTc DMSA in the plasma was high, reaching 89% within the first 5 min, and rising very slightly (n.s.) ith time. The unbound portion of DMSA had a plasma clearance slightly higher than the GFR. Ablation of large amounts of renal tissue, resulting in significant decreases in GFR, did not significantly affect the renal localization of DMSA in the intact portions of the kidneys. These data demonstrate that commonly encountered changes in acid-base balance and hydration will significantly alter the biologic distribution of 99mTc DMSA. These factors should be controlled when carrying out clinical studies.

  9. 99mTc-antigranulocyte bone marrow scintigraphy of breast and prostate skeletal metastases.

    PubMed

    Limouris, G S; Voliotopoulos, V; Stavraka, A; Vlahos, L

    1997-01-01

    Although bone scintigraphy using Tc-99m labelled diphosphonates is a highly sensitive modality for the detection of of the extent of secondary skeletal malignancies, it is often not sufficient since possible bone marrow participation cannot be imaged We make a preliminary report on the usefulness of bone marrow immunoscintigraphy in the follow-up of patients with skeletal metastases due to breast and prostate cancer in parallel with the interpretation of conventional Tc-99m MDP bone scans. Approximately 7 to 9 months after radionuclide therapy both Tc-99m MDP [Hellenic Nuclear Research Center "Democritos". Aghia Paraskevi, Attikil and Tc-99m Anti-Granulocyte BW 250/183 [CIS Bio International, Gif sur Yvette, France] bone scans were performed on 2 prostate cancer patients and 5 women with breast cancer with disseminated bone metastases. Bone scans preceded bone marrow scans. Bone marrow defects were concordant with cortical scans in 4 cases, while they were larger in 4 sites compared to -MDP scan. Four sites in the ribs, shown on -MDP scan could not be detected on antigranulocyte scans. Bone cortex and marrow combined imaging of osseous metastases using different radiotracers increases the information on the real extent of skeletal involvement; the scintigraphic data obtained are valuable for the further decision making for the best possible management of unexpected myelosuppressive side effects as well as the follow-up of the treated cancer patients. PMID:9179204

  10. Micromechanical Resonators for Oscillators and Filters Clark T.-C. Nguyen

    E-print Network

    Nguyen, Clark T.-C.

    Micromechanical Resonators for Oscillators and Filters Clark T.-C. Nguyen Center for Integrated Arbor, MI 48109-2122 Abstract--Fully monolithic, high-Q, micromechanical signal processors are described technology, is detailed, for which the oscillation frequency is controlled by a polysilicon micromechanical

  11. Micromechanical Mixer+Filters Ark-Chew Wong, Hao Ding, and Clark T.-C. Nguyen

    E-print Network

    Nguyen, Clark T.-C.

    Micromechanical Mixer+Filters Ark-Chew Wong, Hao Ding, and Clark T.-C. Nguyen Center for Integrated Arbor, Michigan 48109-2122 ABSTRACT A device comprised of interlinked micromechanical resona- tors path. Recent advances in micromachining technologies that yield high-Q micromechanical resonators [1

  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. 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.

  14. 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.

  15. The Discovery of 2008 TC3 at the Catalina Sky Survey

    Microsoft Academic Search

    Andrea Boattini; E. C. Beshore; G. J. Garradd; A. R. Gibbs; A. D. Grauer; R. E. Hill; R. A. Kowalski; S. M. Larson; R. H. McNaught

    2009-01-01

    The discovery of 2008 TC3, the first natural object to be found outside the atmosphere on its impact course with the Earth, by Richard Kowalski during the course of the Catalina Sky Survey (CSS), is the result of a 'modus operandi' developed over the years to facilitate identification of Near Earth Objects. Such observing approach comprises rapid inspection of the

  16. 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

  17. 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.

  18. 2D Ferromagnetism in the High-Tc Analogue Cs_2AgF_4

    Microsoft Academic Search

    S. E. McLain; D. A. Tennant; J. F. C. Turner; T. Barnes; M. R. Dolgos; Th. Proffen; B. C. Sales; R. I. Bewley

    2005-01-01

    Although the precise mechanism of high-Tc superconductivity in the layered cuprates remains unknown, it is generally thought that strong 2D Heisenberg antiferromagnetism combined with disruptive hole doping is an essential aspect of the phenomenon. Intensive studies of other layered 3d transition metal systems have greatly extended our understanding of strongly correlated electron states, but to date have failed to show

  19. High-Tc Superconductivity in Entirely End-bonded Multi-walled nanotubes

    E-print Network

    Maruyama, Shigeo

    High-Tc Superconductivity in Entirely End-bonded Multi-walled nanotubes Junji Haruyama 1 , Izumi the emergence of superconductivity, such as Tomonaga-Luttinger liquid states and Peierls transition. Carbon nanotubes (CNs) are one of the best candidates for investigating the possibility of 1D superconductivity

  20. d-wave Cooper pairing in multiband models for the high-Tc cuprates

    Microsoft Academic Search

    Carsten Honerkamp; Stefan Uebelacker

    2011-01-01

    We investigate possible reasons for the significant differences of Tcs in high-Tc cuprate compounds, based on renormalization group treatments of downfolded models for the electronic structure. Generally, cuprates with a square like Fermi surface exhibit lower critical temperatures than materials with a more rounded Fermi surface, which contradicts with many theoretical studies of the one band Hubbard model. To resolve

  1. Text classification Naive Bayes NB theory Evaluation of TC Web Search and Text Mining

    E-print Network

    Gray, Alexander

    Text classification Naive Bayes NB theory Evaluation of TC Web Search and Text Mining http://www.cc.gatech.edu/~agray/6240spr11 IIR 13: Text Classification & Naive Bayes Alexander Gray Georgia Institute of Technology, College of Computing 2011 Gray: Text Classification & Naive Bayes 1 / 52 #12;Text classification Naive

  2. Problems of development the pilot lead-bismuth target circuit TC-1 for ADS

    SciTech Connect

    Ignatiev, Sviatoslav; Leonchuk, Mikhail; Orlov, Yury; Pankratov, Dmitry; Suvorov, Gennady; Zabudko, Alexey [Institute for Physics and Power Engineering, 1, Bondarenko sq. Kaluga region 249020 (Russian Federation)

    2007-07-01

    Available in abstract form only. Full text of publication follows: Main problems on development of pilot molten lead-bismuth target circuit of 1 MW proton beam power (TC-1) as an important part of target-blanket accelerator driven system (ADS) for nuclear waste incineration are analyzed. (authors)

  3. Condensation Energy and Tc within the Density Functional Theory for Superconductors

    Microsoft Academic Search

    Stefano de Gironcoli; Jesper W. Krogh; Paolo Giannozzi

    2005-01-01

    We study the behaviour of the density functional theory for superconductors (SCDFT) for two cases: 1) the Coulomb part of the condensation energy (Ec) of a homogeneous electron gas under pairing potential with high angular momentum, and 2) the Tc of niobium under pressure.In the first case, we treat the electronic correlations at the random phase approximation (RPA) level and

  4. Condensation Energy and Tc within the Density Functional Theory for Superconductors

    Microsoft Academic Search

    Malgorzata Wierzbowska; Stefano de Gironcoli; Jesper W. Krogh; Paolo Giannozzi

    2005-01-01

    We study the behaviour of the density functional theory for superconductors (SCDFT) for two cases: 1) the Coulomb part of the condensation energy (Ec) of a homogeneous electron gas under pairing potential with high angular momentum, and 2) the Tc of niobium under pressure. In the first case, we treat the electronic correlations at the random phase approximation (RPA) level

  5. Cares and Concerns of CIE TC8-08: Spatial Appearance Modeling and HDR Rendering

    E-print Network

    Johnson, Garrett M.

    Cares and Concerns of CIE TC8-08: Spatial Appearance Modeling and HDR Rendering Garrett M. Johnson1 appearance models, with an emphasis on high-dynamic range images. High-dynamic range (HDR) images and implementations, psychophysical experimental design, HDR image availability, preference verses accuracy

  6. 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 Columbia, Vancouver, British Columbia, Canada V6T 1Z1 Received 21 August 1996 We generalize the London free-1829 97 50402-4 The London free energy provides a very simple way of studying the vortex lattice

  7. Improvement of drop shock and TC reliability for large die Wafer Level Packages in mobile application

    Microsoft Academic Search

    Jun-Kyu Lee; Yun-Mook Park; In-Soo Kang; Yong-Min Kwon; Kyung-Wook Paik

    2009-01-01

    In this study, board level drop shock and TC reliabilities in terms of solder materials and UBM (under bump metallurgy) structures have been evaluated to suggest optimal structures of WLP (wafer level packaging) with the large die, high pin counts for mobile application. Test vehicles of WLP have been designed with 5.6??5.6 mm die size, 340 um thickness (including backside

  8. Biodistribution and dosimetry of TC-99m P280: A phase I study

    SciTech Connect

    Diggles, L.; Pham, H.L.; Marcus, C. [Harbor-UCLA Medical Center, Torrance, CA (United States)]|[ORISE, Oak Ridge, TN (United States)]|[Diatech, Inc., Londonderry, NH (United States)] [and others

    1995-05-01

    Tc-99m P280 (a symmetrical synthetic dimer of 2 identical peptide monomers containing an RGD mimetic sequence) is a radiolabeled peptide undergoing clinical trials for use in imaging activated platelets. We investigated the biodistribution and dosimetry of intravenous Tc-99m P280 by serial determination of blood, urine and scintigraphic regional activity. Ten normal volunteers (6 male, 4 female, age 44 {plus_minus} 7) received 370 MBq (250 ug of peptide) Tc-99m P280 by intravenous injection. Twelve venous blood samples were collected over 24 hours (hrs) for calculation of blood clearance. Urine clearance was calculated by measuring the activity in the total void at 5 contiguous intervals over 24 hrs, 4 hrs and 24 hrs. The percent of the administered dose in each source organ vs. time was calculated using regions of interest created on the whole body images. Time activity curves were fit to a multi-compartmental model using the Simulation Analysis And Modeling (SAAM) software. Residence times were calculated by integration of the model predicted time activity curves and the dose estimates were performed using standard MIRD techniques. Effective dose equivalent = .010 mSv/MBq. We conclude that clearance of intravenous Tc-99m P280 is principally via the kidneys, with 89% of administered activity cleared from the blood pool within one hr, 33% excreted in the urine within one hr, and 80% excreted in the urine with 24 hrs.

  9. 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

  10. 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.

  11. 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.

  12. TRANSITIONS GAMMA DE BASSE NERGIE ET LECTRONS AUGER DE LA DSINTGRATION 99Mo ~ 99Tc

    E-print Network

    Paris-Sud XI, Université de

    niveaux excités du technetium 99 dont l'un, d'énergie 142 keV est un état isomérique de période 6 plus facilement que le composé de technetium. Vers 600 °C on peut sublimer presque complètement le 99Tc ont été étudiés sur des sources de 99Tcm préparées de la manière suivante : Le technetium est

  13. Charged magnetic domain lines and the magnetism of high-Tc oxides

    Microsoft Academic Search

    Jan Zaanen; Olle Gunnarsson

    1989-01-01

    The breakdown of the antiferromagnetism in the high-Tc oxides is studied taking into account the 3d charge fluctuations. We point out a tendency towards the formation of charged magnetic domain lines if holes are introduced in such a state, which can be viewed as a generalization of soliton of the Su, Schrieffer, and Heeger to two dimensions. In the ground

  14. Origin of superconductive glassy state and extrinsic critical currents in high-Tc oxides

    Microsoft Academic Search

    G. Deutscher; K. A. Mueller

    1987-01-01

    The short coherence length of high-Tc oxides is shown to induce considerable weakening of the pair potential at surfaces and interfaces. It is argued that this effect is responsible for the existence of internal Josephson junctions at twin boundaries, which are at the origin of the superconductive glassy state, as well as for gapless tunneling characteristics.

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

    E-print Network

    that an anion exchange separation step may be used for the purification of a technetium-99 sample. We have developed a purification procedure2 which is a solvent extraction at controlled valence. The technetium-99 to the sea water. Stir with air for 30 min to get Tc04~ and to allow isotope exchange to be completed

  16. Evaluation of the New HOxotope Total Water Isotopologues Instrument Performance During TC4 Through Instrument Intercomparison

    Microsoft Academic Search

    A. S. O'Brien; T. F. Hanisco; J. M. St. Clair; E. M. Weinstock; J. B. Smith; R. L. Herman; R. F. Troy; L. E. Christensen; S. M. Davis; L. M. Avallone; J. G. Anderson

    2007-01-01

    Measurements of the relative abundance of HDO and H2O serve as a sensitive indicator of the convective history of an airmass. We present measurements of total water isotopologues (condensed and vapor phases) from the upper troposphere and lower stratosphere that were obtained by the HOx total water isotopologues instrument (HOxotope) onboard the NASA WB-57 aircraft during the TC4 field campaign.

  17. Cost-effectiveness of routine radiochemical quality assurance testing of technetium Tc 99m radiopharmaceuticals

    SciTech Connect

    Ponto, J.A.; Ponto, L.L.

    1986-05-01

    The cost-effectiveness of performing routine radiochemical quality assurance (QA) testing of technetium Tc 99m radiopharmaceuticals was evaluated. Data were collected retrospectively on use and failures of radiopharmaceuticals over a 30-month period at a university hospital. Cost of quality assurance testing of the radiopharmaceuticals and cost of not performing this routine testing (e.g., repetition of invalid studies) were compared. Possible reasons for failure of radiopharmaceuticals to meet QA standards were examined. Based on these data and an informal survey of the incidence of failures at other nuclear pharmacies, expected radiopharmaceutical failure rates were calculated. The incidence of failures at the study institution was 0.56% (20 of 3775); the other nuclear pharmacies reported similar data. Based on these data, 6 failures per 1000 technetium Tc 99m radiopharmaceuticals prepared were predicted. ''Low tin'' kits (e.g., albumin aggregated) with low-specific-activity sodium pertechnetate Tc 99m were associated with failure to meet QA standards. Direct costs of QA testing were slightly less than direct costs associated with not testing; however, consideration of indirect costs confirmed the cost-effectiveness of QA testing. Routine radiochemical QA testing of technetium Tc 99m radiopharmaceuticals appears to be cost-effective.

  18. Tc99m HMPAO brain perfusion imaging in young Down's syndrome patients

    Microsoft Academic Search

    Nahide Gökçora; Tamer Atasever; Ne?e ?lgin Karabacak; Gülin Vural; K?v?lc?m Gücüyener

    1999-01-01

    Down's syndrome (DS) is characterized by moderate mental retardation and a variety of abnormalities involving multiple organ systems. There is a high incidence of Alzheimer's disease (AD) type dementia beyond the age of 35. In this study, single photon emission computed tomography (SPECT) brain perfusion imaging of young Down's syndrome patients was performed to define the perfusion pattern. Tc-99m HMPAO

  19. Methods for Evaluating Software Architecture: A Banani Roy and T.C. Nicholas Graham

    E-print Network

    Graham, Nick

    Methods for Evaluating Software Architecture: A Survey Banani Roy and T.C. Nicholas Graham and identifying po- tential risks. There have been several methods and techniques to evaluate software. This paper presents a discussion on different software architectural evaluation methods and techniques using

  20. Methods for Evaluating Software Architecture: A Banani Roy and T.C. Nicholas Graham

    E-print Network

    Graham, Nick

    Methods for Evaluating Software Architecture: A Survey Banani Roy and T.C. Nicholas Graham and identifying po­ tential risks. There have been several methods and techniques to evaluate software. This paper presents a discussion on di#erent software architectural evaluation methods and techniques using