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Sample records for avaliacao por tc

  1. Tc7, a Tc1-hitch hiking transposon in Caenorhabditis elegans.

    PubMed Central

    Rezsohazy, R; van Luenen, H G; Durbin, R M; Plasterk, R H

    1997-01-01

    We have found a novel transposon in the genome of Caenorhabditis elegans. Tc7 is a 921 bp element, made up of two 345 bp inverted repeats separated by a unique, internal sequence. Tc7 does not contain an open reading frame. The outer 38 bp of the inverted repeat show 36 matches with the outer 38 bp of Tc1. This region of Tc1 contains the Tc1-transposase binding site. Furthermore, Tc7 is flanked by TA dinucleotides, just like Tc1, which presumably correspond to the target duplication generated upon integration. Since Tc7 does not encode its own transposase but contains the Tc1-transposase binding site at its extremities, we tested the ability of Tc7 to jump upon forced expression of Tc1 transposase in somatic cells. Under these conditions Tc7 jumps at a frequency similar to Tc1. The target site choice of Tc7 is identical to that of Tc1. These data suggest that Tc7 shares with Tc1 all the sequences minimally required to parasitize upon the Tc1 transposition machinery. The genomic distribution of Tc7 shows a striking clustering on the X chromosome where two thirds of the elements (20 out of 33) are located. Related transposons in C. elegans do not show this asymmetric distribution. PMID:9321656

  2. 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.

  3. Mental Health and the TC. Chapter 5.

    ERIC Educational Resources Information Center

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

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

  4. 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 TC

  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. Tc-99m Labeled carrier for imaging

    DOEpatents

    Henze, Eberhard

    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.

  7. 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.

  8. Gauge Model of High-Tc Superconductivity

    NASA Astrophysics Data System (ADS)

    Kui Ng, Sze

    2012-12-01

    A simple gauge model of superconductivity is presented. The seagull vertex term of this gauge model gives an attractive potential between electrons for the forming of Cooper pairs of superconductivity. This gauge model gives a unified description of superconductivity and magnetism including antiferromagnetism, pseudogap phenomenon, stripes phenomenon, paramagnetic Meissner effect, Type I and Type II supeconductivity and high-Tc superconductivity. The doping mechanism of superconductivity is found. It is shown that the critical temperature Tc is related to the ionization energies of elements and can be computed by a formula of Tc. For the high-Tc superconductors such as La2-xSrxCuO4, Y Ba2Cu3O7, and MgB2, the computational results of Tc agree with the experimental results.

  9. Olanzapine induced Q-Tc shortening

    PubMed Central

    Fallah Jahromi, Parisa

    2014-01-01

    Introduction Prolongation of Q-Tc interval is commonly accepted as a surrogate marker for the ability of a drug to cause torsade de pointes. In the present study, safety of olanzapine versus risperidone was compared among a group of patients with schizophrenia to see the frequency of the electrocardiographic alterations induced by those atypical antipsychotics. Method Two hundred and sixty-eight female inpatients with schizophrenia entered in one of the two parallel groups to participate in an open study for random assignment to olanzapine (n = 148) or risperidone (n = 120). Standard 12-lead surface electrocardiogram (ECG) was taken from each patient at baseline, before initiation of treatment, and then at the end of management, just before discharge. The parameters that were assessed included heart rate (HR), P-R interval, QRS interval, Q-T interval (corrected = Q-Tc), ventricular activation time (VAT), ST segment, T wave, axis of QRS, and finally, interventricular conduction process. Results A total of 37.83% of cases in the olanzapine group and 30% in the risperidone group showed some Q-Tc changes; 13.51% and 24.32% of the patients in the olanzapine group showed prolongation and shortening of the Q-Tc, respectively, while changes in the risperidone group were restricted to only prolongation of Q-Tc. Comparison of means showed a significant increment in Q-Tc by risperidone (p = 0.02). Also, comparison of proportions in the olanzapine group showed significantly more cases with shortening of Q-Tc versus its prolongation (p = 0.01). No significant alterations with respect to other variables were evident. Conclusion Olanzapine and risperidone had comparable potentiality for induction of Q-Tc changes, while production of further miscellaneous alterations in ECG was more observable in the olanzapine group compared with the risperidone group. Also shortening of Q-Tc was specific to olanzapine. PMID:25489475

  10. High-Tc and low-Tc dc SQUID electronics

    NASA Astrophysics Data System (ADS)

    Drung, Dietmar

    2003-12-01

    Superconducting quantum interference devices (SQUIDs) are commonly operated in a flux-locked loop (FLL). The SQUID electronics amplifies the small SQUID signal to an acceptable level without adding noise, and it linearizes the transfer function of the SQUID in order to provide sufficient dynamic range. In this paper, the fundamentals of SQUID readout are reviewed including a discussion of preamplifier noise. The basic FLL concepts, direct readout and flux modulation readout, are discussed both with dc bias and bias reversal. Alternative readout concepts such as additional positive feedback (APF), two-stage SQUIDs, SQUID series arrays, relaxation oscillation SQUIDs and digital SQUIDs are briefly described. The FLL dynamics are discussed on the basis of a simple model with finite loop delay. It is shown that with optimized SQUID electronics a system bandwidth of ap18 MHz and a corresponding slew rate of ap8 PHgr0 µs-1 are possible. A novel FLL scheme involving a Smith predictor is presented which allows one to increase the FLL bandwidth to about 100 MHz. The theoretical predictions are experimentally checked using a high-speed SQUID electronics prototype with a small-signal bandwidth of 300 MHz. Methods for increasing the dynamic range of SQUID systems are described: flux-quanta counting and dynamic field compensation (DFC). With DFC, the residual magnetic field at the SQUID can be kept close to zero even if the device is moved in the Earth's field. Therefore, the noise level of a high-Tc magnetometer measured inside a magnetically shielded room (60 fT Hz-1/2 with a 1/f corner at 2 Hz) remained unchanged after moving the device in the magnetic field outside the room (60 µT dc plus 0.8 µT peak-to-peak power line interference).

  11. 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 (α-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.

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

    NASA Astrophysics Data System (ADS)

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

    2015-02-01

    The 2014 Joint IMEKO (International Measurement Confederation) TC1-TC7-TC13 Symposium was organized by RELACRE - Portuguese Association of Accredited Laboratories and the Portuguese Society for Metrology, on 3-5 September 2014. The work of this symposium is reported in this volume. The scope of the symposium includes the main topics covered by the above Technical Committees: - TC1 Education and Training in measurement and Instrumentation - TC7 Measurement Science - TC13 Measurements in Biology and Medicine The effort towards excellence of previous events, in this well established series, is maintained. There has been a special focus on measurement science behind safety and security, with the aim of highlighting the interdisciplinary character of measurement science and the importance of metrology in our daily lives. The discussion was introduced by keynote lectures on measurement challenges in biometrics, health monitoring and social sciences, to promote useful interactions with scientists from different disciplines. The Symposium was attended by experts working in these areas from 18 countries, including USA, Japan and China, and provided a useful forum for them to share and exchange their work and ideas. In total over fifty papers are included in the volume, organized according to the presentation sessions. Each paper was independently peer-reviewed by two reviewers from a distinguished international panel. The Symposium was held in Funchal, capital of Madeira Islands, known as the Atlantic Pearl. This wonderful Atlantic archipelago, formed by Madeira and Porto Santo islands, discovered in the 14th century, was chosen to host the 2014 IMEKO TC1-TC7-TC13 Joint Symposium ''Measurement Science behind Safety and Security''. It was the first territory discovered by the Portuguese sailors, when set out to discover a new world, in an epic journey where instrumentation and quality of measurement played a central role in the success of the enterprise, and gave an

  13. Target site choice of the related transposable elements Tc1 and Tc3 of Caenorhabditis elegans.

    PubMed Central

    van Luenen, H G; Plasterk, R H

    1994-01-01

    We have investigated the target choice of the related transposable elements Tc1 and Tc3 of the nematode C. elegans. The exact locations of 204 independent Tc1 insertions and 166 Tc3 insertions in an 1 kbp region of the genome were determined. There was no phenotypic selection for the insertions. All insertions were into the sequence TA. Both elements have a strong preference for certain positions in the 1 kbp region. Hot sites for integration are not clustered or regularly spaced. The orientation of the integrated transposon has no effect on the distribution pattern. We tested several explanations for the target site preference. If simple structural features of the DNA (e.g. bends) would mark hot sites, we would expect the patterns of the two related transposons Tc1 and Tc3 to be similar; however we found them to be completely different. Furthermore we found that the sequence at the donor site has no effect on the choice of the new insertion site, because the insertion pattern of a transposon that jumps from a transgenic donor site is identical to the insertion pattern of transposons jumping from endogenous genomic donor sites. The most likely explanation for the target choice is therefore that the primary sequence of the target site is recognized by the transposase. However, alignment of the Tc1 and Tc3 integration sites does not reveal a strong consensus sequence for either transposon. PMID:8127662

  14. 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.

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

    PubMed

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

    2014-07-01

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

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

    SciTech Connect

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

    1984-01-01

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

  17. Adoptive transfer of Tc1 or Tc17 cells elicits antitumor immunity against established melanoma through distinct mechanisms.

    PubMed

    Yu, Yu; Cho, Hyun-Ii; Wang, Dapeng; Kaosaard, Kane; Anasetti, Claudio; Celis, Esteban; Yu, Xue-Zhong

    2013-02-15

    Adoptive cell transfer (ACT) of ex vivo-activated autologous tumor-reactive T cells is currently one of the most promising approaches for cancer immunotherapy. Recent studies provided some evidence that IL-17-producing CD8(+) (Tc17) cells may exhibit potent antitumor activity, but the specific mechanisms have not been completely defined. In this study, we used a murine melanoma lung-metastasis model and tested the therapeutic effects of gp100-specific polarized type I CD8(+) cytotoxic T (Tc1) or Tc17 cells combined with autologous bone marrow transplantation after total body irradiation. Bone marrow transplantation combined with ACT of antitumor (gp100-specific) Tc17 cells significantly suppressed the growth of established melanoma, whereas Tc1 cells induced long-term tumor regression. After ACT, Tc1 cells maintained their phenotype to produce IFN-γ, but not IL-17. However, although Tc17 cells largely preserved their ability to produce IL-17, a subset secreted IFN-γ or both IFN-γ and IL-17, indicating the plasticity of Tc17 cells in vivo. Furthermore, after ACT, the Tc17 cells had a long-lived effector T cell phenotype (CD127(hi)/KLRG-1(low)) as compared with Tc1 cells. Mechanistically, Tc1 cells mediated antitumor immunity primarily through the direct effect of IFN-γ on tumor cells. In contrast, despite the fact that some Tc17 cells also secreted IFN-γ, Tc17-mediated antitumor immunity was independent of the direct effects of IFN-γ on the tumor. Nevertheless, IFN-γ played a critical role by creating a microenvironment that promoted Tc17-mediated antitumor activity. Taken together, these studies demonstrate that both Tc1 and Tc17 cells can mediate effective antitumor immunity through distinct effector mechanisms, but Tc1 cells are superior to Tc17 cells in mediating tumor regression. PMID:23315072

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

    NASA Technical Reports Server (NTRS)

    Dulac, J.; Alvarez, H.

    1991-01-01

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

  19. Ultrasonic attenuation studies in high Tc superconductors

    NASA Astrophysics Data System (ADS)

    Shen, Zhong Cheng; Jiang, Zuo

    2005-04-01

    In this paper a great number of mechanical relaxation spectrum experiment results in the mixed state of high Tc superconductors have been summarized. A new low frequency mechanical relaxation spectrum apparatus have been shown. We pointed out that the mechanical relaxation peaks are attributed to anelastic relaxation processes and the transition of rigidly pinned FLL into a depinned state.

  20. 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…

  1. MI2TC_CMV_HDF_NRT

    Atmospheric Science Data Center

    2016-06-08

    MI2TC_CMV_HDF_NRT MISR Level 2 Cloud Motion Vectors product in near real time as HDF format files Project Title:  MISR Discipline:  ... 1 session (10-50 minutes) File Format:  HDF Tools:  HTTP Access: Data Pool Search and Order:  ...

  2. Development of Tc(IV)-Incorporated Fe Minerals to Enhance 99Tc Retention in Glass Waste Form

    SciTech Connect

    Um, Wooyong; Luksic, Steven A.; Wang, Guohui; Kim, Dong-Sang; Schweiger, Michael J.; Hrma, Pavel R.; Kruger, Albert A.

    2015-03-17

    Iron minerals have been considered to be good hosts for Tc immobilization because the Tc(IV) ion substitutes for Fe(III) in the crystal structure of the Fe oxide due to similarities in (1) cation size [Tc(IV) = 78.5 pm ; Fe(III) = 69 or 78.5 pm], (2) metal-oxygen interatomic distance (Tc—O = 0.199 nm, Fe—O = 0.203 nm), (3) number of coordinating oxygen atoms (both 6-fold coordinated), and (4) the redox potential (Eh=ca. +20 mV at pH = 7) for a redox couple between Tc(VII)/Tc(IV) and Fe(III)/Fe(II). Magnetite, maghemite, and trevorite are iron oxide minerals and all belong to spinel mineral group. Laboratory testing shows that Tc can be removed from aqueous waste solutions by a process of Tc reduction from Tc(VII) to Tc(IV) followed by co-precipitation with iron oxide minerals during recrystallization of Fe(OH)2(s) used as an initial solid precursor. X-ray absorption near edge structure (XANES) spectroscopy confirmed that Tc was in the +4 oxidation state in final Tc-Fe minerals. The Tc-incorporated Fe minerals were also tested for Tc retention in glass melts at different temperatures between 600 – 1,000 oC in a furnace. After being cooled in air, the solid glass specimens collected at different temperatures were analyzed for Tc oxidation state using XANES and Tc retention using liquid scintillation counting (LSC). Even though Tc(IV) started to reoxidize at 600 oC, Tc retention in the final glass specimen prepared with Tc-incorporated Fe mineral even at high temperatures was at least two times higher than glass prepared with KTcO4 salt. Higher Tc retention in glass is considered to result from limited and delayed Tc volatilization process due to Fe mineral encapsulation for Tc. Therefore, the results showing the presence of Tc(IV) in the Fe mineral structure indicate strong possibility to enhance Tc retention in borosilicate glass as well as to reduce the remediation costs at the Hanford Site.

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

    SciTech Connect

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

    1984-01-01

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

  4. Inverse correlation between quasiparticle mass and Tc in a cuprate high-Tc superconductor

    PubMed Central

    Putzke, Carsten; Malone, Liam; Badoux, Sven; Vignolle, Baptiste; Vignolles, David; Tabis, Wojciech; Walmsley, Philip; Bird, Matthew; Hussey, Nigel E.; Proust, Cyril; Carrington, Antony

    2016-01-01

    Close to a zero-temperature transition between ordered and disordered electronic phases, quantum fluctuations can lead to a strong enhancement of electron mass and to the emergence of competing phases such as superconductivity. A correlation between the existence of such a quantum phase transition and superconductivity is quite well established in some heavy fermion and iron-based superconductors, and there have been suggestions that high-temperature superconductivity in copper-oxide materials (cuprates) may also be driven by the same mechanism. Close to optimal doping, where the superconducting transition temperature Tc is maximal in cuprates, two different phases are known to compete with superconductivity: a poorly understood pseudogap phase and a charge-ordered phase. Recent experiments have shown a strong increase in quasiparticle mass m* in the cuprate YBa2Cu3O7-δ as optimal doping is approached, suggesting that quantum fluctuations of the charge-ordered phase may be responsible for the high-Tc superconductivity. We have tested the robustness of this correlation between m* and Tc by performing quantum oscillation studies on the stoichiometric compound YBa2Cu4O8 under hydrostatic pressure. In contrast to the results for YBa2Cu3O7-δ, we find that in YBa2Cu4O8, the mass decreases as Tc increases under pressure. This inverse correlation between m* and Tc suggests that quantum fluctuations of the charge order enhance m* but do not enhance Tc. PMID:27034989

  5. Soft-tissue uptake of 99mTc-diphosphonate and 99mTc-pyrophosphate in amyloidosis.

    PubMed

    Janssen, S; Piers, D A; van Rijswijk, M H; Meijer, S; Mandema, E

    1990-01-01

    This study describes the results of scintigraphy with 99mTc-labeled methylene-diphosphonate (99mTc-MDP) and pyrophosphate (99mTc-PYP) as a noninvasive test for the distribution of organ involvement in five different types of amyloidosis. Scintigraphy with 99mTc-labeled phosphates appeared to be a sensitive noninvasive screening test for the extent and the distribution of organ involvement in systemic AA and systemic AL amyloidosis as well as in local bronchial amyloid, local dermal amyloid, and familial amyloidotic polyneuropathy. Echocardiography, however, was more sensitive for demonstrating cardiac involvement in systemic amyloidosis than 99mTc-MDP or 99mTc-PYP scintigraphy. 99mTc-MDP images showed a better contrast than 99mTc-PYP images, although there was no difference in the extent or the intensity of soft-tissue uptake. PMID:2166666

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

    NASA Astrophysics Data System (ADS)

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

    2014-12-01

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

  7. ISO/TC 172 'Optics And Optical Instruments'

    NASA Astrophysics Data System (ADS)

    Kittel, Hans F.

    1989-04-01

    In the sixties and seventies, optical items were dealt with in several different Technical Committees of the International Standardization Organization (ISO). TC 10 'Technical drawings' got prepared to day down drawing rules for technical components, TC 22 'Road vehicles' defined terms of physiological optics because of the connection between seeing and driving motor vehicles, TC 59 'Building construction' standardized geodetic instruments, TC 94 'Personal safety - Protective clothing and equipment laid down requirements for sun glasses, and finally Working Group 12 of TC 42 'Photography' was going to work on various optical test methods and requirements for coatings.

  8. 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

  9. Shock compaction of high- Tc superconductors

    SciTech Connect

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

    1990-09-01

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

  10. 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.

  11. Telecom 2-A (TC2A)

    NASA Technical Reports Server (NTRS)

    Dulac, J.; Latour, J.

    1991-01-01

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

  12. High- Tc thin-film magnetometer

    SciTech Connect

    Miklich, A.H.; Wellstood, F.C.; Kingston, J.J.; Clarke, J. ); Colclough, M.S. ); Cardona, A.H.; Bourne, L.C.; Olson, W.L.; Eddy, M.M. )

    1990-09-01

    We have constructed and tested high-{Tc} magnetometers by coupling a high-{Tc} thin-film Superconducting QUantum Interference Device (SQUID) to two different high-{Tc} thin-film flux transformers. The SQUID was made from Tl{sub 2}CaBa{sub 2}Cu{sub 2}O{sub 8+y} films grown on MgO, with junctions consisting of native grain boundaries. The flux transformers were made from YBa{sub 2}Cu{sub 3}O{sub 7-x}, and each had 10-turn input coils and a single-turn pickup loop. The first transformer, which was patterned with a combination of shadow masks and photolithography, yielded a magnetic field gain of about {minus}7.5, functioned up to 79 K, and gave a magnetic field sensitivity B{sub N} (10 Hz) {approx} 3.1 pT Hz{sup {minus}1/2}at 38 K. The second transformer, which was patterned entirely by photolithography, yielded a gain of about {minus}8.7, functioned up to 25 K, and had a sensitivity B{sub N} (10 Hz) {approx} 3.5 pT Hz{sup {minus}1/2} at 4.2 K. In both cases, the limiting noise arose in the SQUID. 10 refs., 5 figs., 1 tab.

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

    SciTech Connect

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

    2007-07-01

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

  14. 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.

  15. Interdecadal variation of TC frequency in Japan

    NASA Astrophysics Data System (ADS)

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

    2015-07-01

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

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

    SciTech Connect

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

    2006-06-01

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

  17. 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

  18. Tc17 Cells in Immunity and Systemic Autoimmunity.

    PubMed

    Liang, Yan; Pan, Hai-Feng; Ye, Dong-Qing

    2015-01-01

    Tc17 cells-a subset of CD8(+)T cells-have recently been identified that are characterized by the production of interleukin (IL)-17. Cytokines IL-6 and transforming growth factor-beta 1 (TGF-β1) and transcription factors signaling transducers and activators of transcription (STAT)3, retinoic acid receptor-related orphan nuclear receptor gamma (RORγt), and interferon regulatory factor (IRF)4 are necessary for differentiation of Tc17 cells, controlling expression of molecules essential for Tc17 cell trafficking and function. Current human researches have determined the significance of CD161 expression as either a marker of Tc17 cells or as an effector and regulator of Tc17 cell function. Noncytotoxic Tc17 cells possess a high plasticity to convert into IFN-γ producing cells, which exhibit strong cytotoxic activity. The importance of in vivo plasticity of Tc17 cells for the induction of autoimmune diseases has been demonstrated and Tc17 cells potentially represent novel therapeutic targets in autoimmune diseases. The involvement of interleukin (IL)-17-producing CD8(+)T cells (Tc17) in various conditions, such as infection, cancer, and autoimmune inflammation, has been documented in both humans and mice; however, Tc17 cells have received only marginal attention. Here, we provide an overview of the cytokines and chemokines that characterize the murine and human Tc17 cells. Moreover, we discuss signaling pathways, molecular interactions, and transcriptional events that contribute to Tc17 differentiation and acquisition of effector functions. Also considered is the basis of Tc17 cell plasticity toward the Tc1 lineage, and we suggest that in vivo plasticity of Tc17 cells may be a key feature of Tc17 cell biology in autoimmune diseases. Furthermore, current human researches have revealed that Tc17 cells are different than that in mice because all of them express CD161 and exclusively originate from CD161 precursors present in umbilical cord blood. Finally, we focus on the

  19. Pharmacokinetics of the phosphatidylserine tracers 99mTc-lactadherin and 99mTc-annexin V in pigs

    PubMed Central

    2013-01-01

    Background Phosphatidylserine (PS) is a phospholipid normally located in the inner leaflet of the cell membrane. PS is translocated from the inner to the outer leaflet of the plasma membrane during the early stages of apoptosis and in necrosis. In cell and animal studies, reversible PS externalisation to the outer membrane leaflet has been observed in viable cells. Hence, PS markers have been proposed as markers of both reversibly and irreversibly damaged cells. The purpose of this experimental study in pigs was to investigate the kinetics of the newly introduced PS marker technetium-99m-labelled lactadherin (99mTc-lactadherin) in comparison with the well-known PS tracer 99mTc-annexin V with special reference to the renal handling of the tracers. The effective dose for humans was estimated from the biodistribution in 24 mice. Methods Nine anaesthetised pigs randomly allocated into two treatment groups were administered a single injection of either 99mTc-lactadherin or 99mTc-annexin V. Renal perfusion was assessed by simultaneous injection of 51Cr-EDTA. Throughout the examinations, planar, dynamic scintigraphy of the trunk was performed, urine was collected and arterial and renal vein blood was sampled. The effective dose was estimated using the adult male phantom from the RADAR website. Results 99mTc-lactadherin was cleared four times faster from plasma than 99mTc-annexin V, 57 ± 13 ml/min (mean ± SD) versus 14 ± 2 ml/min. 99mTc-lactadherin had a predominant uptake in the liver, whereas 99mTc-annexin V was primarily taken up by the kidneys. The estimated effective human dose after single injection of 99mTc-lactadherin and 99mTc-annexin V was 5.8 and 11 μSv/MBq, respectively. Conclusions The high hepatic uptake of 99mTc-lactadherin compromises the use of 99mTc-lactadherin for imaging PS externalisation in the liver. Due to scatter from the liver, the use of in vivo visualisation of PS externalisation in the lower thorax and upper abdomen by 99mTc

  20. High Tc superconducting materials and devices

    NASA Technical Reports Server (NTRS)

    Haertling, Gene H.

    1990-01-01

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

  1. Portable exhausters POR-004 SKID B, POR-005 SKID C, POR-006 SKID D storage plan

    SciTech Connect

    Nelson, O.D.

    1997-09-04

    This document provides a storage plan for portable exhausters POR-004 SKID B, POR-005 SKID C, AND POR-006 SKID D. The exhausters will be stored until they are needed by the TWRS (Tank Waste Remediation Systems) Saltwell Pumping Program. The storage plan provides criteria for portable exhauster storage, periodic inspections during storage, and retrieval from storage.

  2. Pressure and high-Tc superconductivity in sulfur hydrides

    PubMed Central

    Gor’kov, Lev P.; Kresin, Vladimir Z.

    2016-01-01

    The paper discusses fundamentals of record-TC superconductivity discovered under high pressure in sulfur hydride. The rapid increase of TC with pressure in the vicinity of Pcr ≈ 123GPa is interpreted as the fingerprint of a first-order structural transition. Based on the cubic symmetry of the high-TC phase, it is argued that the lower-TC phase has a different periodicity, possibly related to an instability with a commensurate structural vector. In addition to the acoustic branches, the phonon spectrum of H3S contains hydrogen modes with much higher frequencies. Because of the complex spectrum, usual methods of calculating TC are here inapplicable. A modified approach is formulated and shown to provide realistic values for TC and to determine the relative contributions of optical and acoustic branches. The isotope effect (change of TC upon Deuterium for Hydrogen substitution) originates from high frequency phonons and differs in the two phases. The decrease of TC following its maximum in the high-TC phase is a sign of intermixing with pairing at hole-like pockets which arise in the energy spectrum of the cubic phase at the structural transition. On-pockets pairing leads to the appearance of a second gap and is remarkable for its non-adiabatic regime: hydrogen mode frequencies are comparable to the Fermi energy. PMID:27167334

  3. Pressure and high-Tc superconductivity in sulfur hydrides.

    PubMed

    Gor'kov, Lev P; Kresin, Vladimir Z

    2016-01-01

    The paper discusses fundamentals of record-TC superconductivity discovered under high pressure in sulfur hydride. The rapid increase of TC with pressure in the vicinity of Pcr ≈ 123GPa is interpreted as the fingerprint of a first-order structural transition. Based on the cubic symmetry of the high-TC phase, it is argued that the lower-TC phase has a different periodicity, possibly related to an instability with a commensurate structural vector. In addition to the acoustic branches, the phonon spectrum of H3S contains hydrogen modes with much higher frequencies. Because of the complex spectrum, usual methods of calculating TC are here inapplicable. A modified approach is formulated and shown to provide realistic values for TC and to determine the relative contributions of optical and acoustic branches. The isotope effect (change of TC upon Deuterium for Hydrogen substitution) originates from high frequency phonons and differs in the two phases. The decrease of TC following its maximum in the high-TC phase is a sign of intermixing with pairing at hole-like pockets which arise in the energy spectrum of the cubic phase at the structural transition. On-pockets pairing leads to the appearance of a second gap and is remarkable for its non-adiabatic regime: hydrogen mode frequencies are comparable to the Fermi energy. PMID:27167334

  4. Pressure and high-Tc superconductivity in sulfur hydrides

    NASA Astrophysics Data System (ADS)

    Gor’Kov, Lev P.; Kresin, Vladimir Z.

    2016-05-01

    The paper discusses fundamentals of record-TC superconductivity discovered under high pressure in sulfur hydride. The rapid increase of TC with pressure in the vicinity of Pcr ≈ 123GPa is interpreted as the fingerprint of a first-order structural transition. Based on the cubic symmetry of the high-TC phase, it is argued that the lower-TC phase has a different periodicity, possibly related to an instability with a commensurate structural vector. In addition to the acoustic branches, the phonon spectrum of H3S contains hydrogen modes with much higher frequencies. Because of the complex spectrum, usual methods of calculating TC are here inapplicable. A modified approach is formulated and shown to provide realistic values for TC and to determine the relative contributions of optical and acoustic branches. The isotope effect (change of TC upon Deuterium for Hydrogen substitution) originates from high frequency phonons and differs in the two phases. The decrease of TC following its maximum in the high-TC phase is a sign of intermixing with pairing at hole-like pockets which arise in the energy spectrum of the cubic phase at the structural transition. On-pockets pairing leads to the appearance of a second gap and is remarkable for its non-adiabatic regime: hydrogen mode frequencies are comparable to the Fermi energy.

  5. 99mTc-ciprofloxacin for diagnosis of bacterial infection

    NASA Astrophysics Data System (ADS)

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

    2015-05-01

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

  6. Peak Effect in High-Tc Superconductors

    NASA Astrophysics Data System (ADS)

    Ling, Xinsheng

    1996-03-01

    Like many low-Tc superconductors, high-quality YBCO single crystals are found(X.S. Ling and J.I. Budnick, in Magnetic Susceptibility of Superconductors and Other Spin Systems), edited by R.A. Hein, T.L. Francavilla, and D.H. Liebenberg (Plenum Press, New York, 1991), p.377. to exhibit a striking peak effect. In a magnetic field, the temperature dependence of the critical current has a pronounced peak below T_c(H). Pippard(A.B. Pippard, Phil. Mag. 19), 217 (1969)., and subsequently Larkin and Ovchinnikov(A.I. Larkin and Yu.N. Ovchinnikov, J. Low Temp. Phys. 34), 409 (1979)., attributed the onset of the peak effect to a softening of the vortex lattice. In this talk, the experimental discovery^1 of the peak effect in high-Tc superconductors will be described, followed by a brief historical perspective of the understanding of this phenomenon and a discussion of a new model(X.S. Ling, C. Tang, S. Bhattacharya, and P.M. Chaikin, cond-mat/9504109, (NEC Preprint 1995).) for the peak effect. In this model, the peak effect is an interesting manifestation of the vortex-lattice melting in the presence of weak random pinning potentials. The rise of critical current with increasing temperature is a signature of the ``melting'' of the Larkin domains. This work is done in collaboration with Joe Budnick, Chao Tang, Shobo Bhattacharya, Paul Chaikin, and Boyd Veal.

  7. Imaging of irradiated liver with Tc-99m-sulfur colloid and Tc-99m-IDA

    SciTech Connect

    Gelfand, M.J.; Saha, S.; Aron, B.S.

    1981-09-01

    In three cases, irradiated regions of liver failed to concentrate Tc-99m-sulfur colloid. In two of these three, imaging with Tc-99m-acetanilide iminodiacetic acid (IDA) agents within five days showed near normal hepatic uptake of this hepatobiliary imaging agent. The hepatic parenchymal cells may be imaged with Tc-99m-IDA in some irradiated regions of liver, despite loss of reticuloendothelial cell function.

  8. Interlayer tunneling mechanism of high- Tc superconductivity: Nonuniversal discontinuity in specific heat

    NASA Astrophysics Data System (ADS)

    Sudbø, A.

    1994-12-01

    Interlayer tunneling mechanism of high- Tc superconductivity is considered with emphasis on the thermodynamics close to T = Tc. For a k-independent interlayer Josephson coupling TJ, we find that, for | T - Tc|/ Tc ≪ 1, the gap on the Fermi surface is Δ( T) = Tcη( Tc; TJ)(1 - T/ Tc) α, with mean-field exponent α = {1}/{2}. The nonuniversal prefactor η( Tc; TJ) drops rapidly from the BCS-value π( {8}/{7}ς(3)) {1}/{2} ≈ 3.06 , as a function of TJ. The nor malized. specific heat discontinuity at T = Tc, ΔCv/ Nn(0) Tc = η2( Tc; TJ)/[1 - TJ/4 Tc] 2, increases initiall y rapidly as a function of TJ, while lim TJ → 0 ΔCv/ Nn(0) Tc = 8 π2/7 ς(3) ≈ 9.4.

  9. 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

  10. 99Tc Process Monitoring System In-Lab Performance Characterization

    SciTech Connect

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

    2014-01-01

    Executive Summary A 99Tc Process Monitoring (Tc-Mon) System has been designed and built for deployment at the recently constructed 200 West Pump & Treat (200W P&T) Plant in the 200 West Area ZP-1 Operable Unit of the Hanford Site. The plant is operated by CH2M Hill Plateau Remediation Company (CHPRC). The Tc-Mon system was created through collaboration between Pacific Northwest National Laboratory (PNNL) and Burge Environmental, Inc. The new system’s design has been optimized based on experience from an earlier field test (2011) of a prototype system at the 200W-ZP-1 Interim Pump & Treat Plant. A portion of the new 200W P&T Plant is dedicated to removal of 99Tc from contaminated groundwater in the 200 West Area. 99Tc, as the pertechnetate anion (99TcO4-), is remediated through delivery of water into two trains (Trains A and B) of three tandem extraction columns filled with Purolite A530E resin. The resin columns cannot be regenerated; therefore, once they have reached their maximum useful capacity, the columns must be disposed of as radioactive waste. The Tc-Mon system’s primary duty will be to periodically sample and analyze the effluents from each of the two primary extraction columns to determine 99Tc breakthrough. The Tc-Mon system will enable the CH2M Hill Plateau Remediation Company (CHPRC) to measure primary extraction column breakthrough on demand. In this manner, CHPRC will be able to utilize each extraction column to its maximum capacity. This will significantly reduce column disposal and replacement costs over the life of the plant. The Tc-Mon system was constructed by Burge Environmental, Inc. and was delivered to PNNL in June 2013 for setup and initial hardware and software performance testing in the 325 Building. By early July, PNNL had initiated an in-laboratory performance characterization study on the system. The objective was to fully calibrate the system and then evaluate the quality of the analytical outputs 1) against a series of clean

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

    SciTech Connect

    Aburano, T.; Yokoyama, K.; Shuke, N.; Kinuya, S.; Takayama, T.; Tonami, N.; Hisada, K. )

    1991-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2012-03-01

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

  13. Relative biological effectiveness of 99mTc radiopharmaceuticals.

    PubMed

    Narra, V R; Sastry, K S; Goddu, S M; Howell, R W; Strand, S E; Rao, D V

    1994-12-01

    The radiotoxicity of three 99mTc-labeled compounds is investigated using spermatogenesis in mouse testis as the experimental model, and spermatogonial cell survival as the biological end point. The radiopharmaceuticals studied are pertechnetate (99mTcO4-), pyrophosphate (99mTc-PYP), and hydroxyethylene diphosphate (99mTc-HDP). The mean lethal doses at 37% survival (D37) are 0.70 +/- 0.06, 0.84 +/- 0.13, and 0.59 +/- 0.08 Gy for 99mTcO4-, 99mTc-PYP, and 99mTc-HDP, respectively. When these results are compared with the D37 value obtained with external x rays or internal gamma rays, the relative biological effectiveness (RBE) of these compounds are 0.94 +/- 0.09, 0.79 +/- 0.13, and 1.1 +/- 0.16, respectively. These results show that the radiotoxicity of 99mTc in mouse testis is essentially similar to that of low-LET radiations (i.e., RBE approximately 1). To understand these results, the distribution of these radiocompounds in the testis is determined and correlated with the observed RBE values. The expected range of RBE values for 99mTc radiopharmaceuticals in organs is 0.95 to 1.5, depending on the fraction of organ activity that is bound to DNA. This suggests that the Auger electrons emitted in the decay of 99mTc are not capable of causing extreme toxicity in vivo. These results provide further support for 99mTc as the radionuclide of choice for imaging in nuclear medicine. PMID:7700199

  14. (99m)Tc-labeled porphyrin-lipid nanovesicles.

    PubMed

    Lee, Jae-Ho; Shao, Shuai; Cheng, Kenneth T; Lovell, Jonathan F; Paik, Chang H

    2015-01-01

    Porphyrin-lipid nanovesicles (PLN) have been developed with intrinsic capabilities as activatable multimodal photonic contrast agents. Radiolabeling of PLN encapsulating drugs could eventually be able to provide quantitative in vivo information for diagnosing and treating diseases. In this study, we developed (99m)Tc-labeled porphyrin-lipid nanovesicles ((99m)Tc-PLN) as a cargo-encapsulated formulation without significant impact on liposome integrity and encapsulation stability. 50 mM calcein was encapsulated into PLN by probe sonication. The size of the PLN was about 150 nm. The PLN were then reacted with (99m)Tc using SnCl2 dissolved in 1 mM HCl as a reducing agent and incubated for 10 min at 22 °C. The radiolabeling efficiency and stability of (99m)Tc-PLN were evaluated by instant thin-layer chromatography and low-pressure liquid chromatography (LPLC). (99m)Tc labeling was successful with a >92% labeling efficiency. LPLC showed that the liposomal elution peaks of the porphyrin-lipid and the calcein overlapped with the radioactivity elution peak of (99m)Tc-labeled PLN. The (99m)Tc-labeling procedure did not change the size of PLN. Encapsulated calcein remained inert inside PLN. Thus, this work lays out a simple and effective radiolabeling method using SnCl2 in HCl in the preparation of (99m)Tc-PLN. PMID:24963601

  15. 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.

  16. Importance of markers in Tc-99m pyrophosphate myocardial images

    SciTech Connect

    Vasavada, P.J.; Micklos, T.J.; Nishiyama, H.

    1985-02-01

    A false-positive Tc-99m PYP myocardial scan may result due to gastric activity from the breakdown of radiopharmaceuticals and accumulation of Tc-99m pertechnetate in gastric cells. Importance of anatomic landmarks during early blood pool images is emphasized to prevent this error.

  17. 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.

  18. Iron oxide waste form for stabilizing 99Tc

    NASA Astrophysics Data System (ADS)

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

    2012-10-01

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

  19. Cytological effects of Tc on young soybean plants

    SciTech Connect

    Neel, J.W.; Onasch, M.A. )

    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.

  20. RILEM TC ISR Summer 2015 Activity Report

    SciTech Connect

    Le Pape, Yann

    2015-08-01

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

  1. 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.

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

    SciTech Connect

    Errico, Leonardo; Darriba, German; Renteria, Mario; Tang Zhengning; Emmerich, Heike; Cottenier, Stefaan

    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.

  3. 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

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

    SciTech Connect

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

    1984-01-01

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

  5. Breast-milk radioactivity after a Tc-99m DTPA aerosol/Tc-99m MAA lung study

    SciTech Connect

    Mountford, P.J.; Hall, F.M.; Wells, C.P.; Coakley, A.J.

    1984-10-01

    Measurements were made of the concentration of Tc-99m activity in samples of breast milk following an administration of Tc-99m DTPA aerosol for a lung ventilation image and one of Tc-99m MAA for lung perfusion. The activity was 222 nCi/ml of milk (8.2 kBq/ml) at 2 hr after the MAA injection, and it was found to be excreted exponentially with an effective half-life of 4.6 hr. There was a small incorporation of Tc-99m into breast-milk protein. The authors conclude that the combined use of these two Tc-99m agents did not indicate the interruption of breast feeding beyond 24 hr after administration of the MAA, and that for an aerosol ventiliation study alone, breast feeding need not be interrupted for more than 4 hr after the test.

  6. Impeding (99)Tc(IV) mobility in novel waste forms.

    PubMed

    Lee, Mal-Soon; Um, Wooyong; Wang, Guohui; Kruger, Albert A; Lukens, Wayne W; Rousseau, Roger; Glezakou, Vassiliki-Alexandra

    2016-01-01

    Technetium ((99)Tc) is an abundant, long-lived radioactive fission product whose mobility in the subsurface is largely governed by its oxidation state. Tc immobilization is crucial for radioactive waste management and environmental remediation. Tc(IV) incorporation in spinels has been proposed as a novel method to increase Tc retention in glass waste forms during vitrification. However, experiments under high-temperature and oxic conditions show reoxidation of Tc(IV) to volatile pertechnetate, Tc(VII). Here we examine this problem with ab initio molecular dynamics simulations and propose that, at elevated temperatures, doping with first row transition metal can significantly enhance Tc retention in magnetite in the order Co>Zn>Ni. Experiments with doped spinels at 700 °C provide quantitative confirmation of the theoretical predictions in the same order. This work highlights the power of modern, state-of-the-art simulations to provide essential insights and generate theory-inspired design criteria of complex materials at elevated temperatures. PMID:27357121

  7. 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

  8. Interactions of Tc(IV) with humic substances.

    PubMed

    Boggs, Mark A; Minton, Travis; Dong, Wenming; Lomasney, Samuel; Islam, Mohammed R; Gu, Baohua; Wall, Nathalie A

    2011-04-01

    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)2(0). Binding constants were found to be 6.8 and between 3.9 and 4.3, for logβ1,-1,1 and logβ1,-2,1, respectively; these values were little modified by a change of ionic strength, in most cases, between 0.1 and 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, whereas TcO(OH)2(0) and TcO(OH)2-HA are the major species, in the pH 6-8 range. PMID:21366306

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

    SciTech Connect

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

    1989-03-01

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

  10. Impeding 99Tc(IV) mobility in novel waste forms

    PubMed Central

    Lee, Mal-Soon; Um, Wooyong; Wang, Guohui; Kruger, Albert A.; Lukens, Wayne W.; Rousseau, Roger; Glezakou, Vassiliki-Alexandra

    2016-01-01

    Technetium (99Tc) is an abundant, long-lived radioactive fission product whose mobility in the subsurface is largely governed by its oxidation state. Tc immobilization is crucial for radioactive waste management and environmental remediation. Tc(IV) incorporation in spinels has been proposed as a novel method to increase Tc retention in glass waste forms during vitrification. However, experiments under high-temperature and oxic conditions show reoxidation of Tc(IV) to volatile pertechnetate, Tc(VII). Here we examine this problem with ab initio molecular dynamics simulations and propose that, at elevated temperatures, doping with first row transition metal can significantly enhance Tc retention in magnetite in the order Co>Zn>Ni. Experiments with doped spinels at 700 °C provide quantitative confirmation of the theoretical predictions in the same order. This work highlights the power of modern, state-of-the-art simulations to provide essential insights and generate theory-inspired design criteria of complex materials at elevated temperatures. PMID:27357121

  11. Impeding 99Tc(IV) mobility in novel waste forms

    NASA Astrophysics Data System (ADS)

    Lee, Mal-Soon; Um, Wooyong; Wang, Guohui; Kruger, Albert A.; Lukens, Wayne W.; Rousseau, Roger; Glezakou, Vassiliki-Alexandra

    2016-06-01

    Technetium (99Tc) is an abundant, long-lived radioactive fission product whose mobility in the subsurface is largely governed by its oxidation state. Tc immobilization is crucial for radioactive waste management and environmental remediation. Tc(IV) incorporation in spinels has been proposed as a novel method to increase Tc retention in glass waste forms during vitrification. However, experiments under high-temperature and oxic conditions show reoxidation of Tc(IV) to volatile pertechnetate, Tc(VII). Here we examine this problem with ab initio molecular dynamics simulations and propose that, at elevated temperatures, doping with first row transition metal can significantly enhance Tc retention in magnetite in the order Co>Zn>Ni. Experiments with doped spinels at 700 °C provide quantitative confirmation of the theoretical predictions in the same order. This work highlights the power of modern, state-of-the-art simulations to provide essential insights and generate theory-inspired design criteria of complex materials at elevated temperatures.

  12. Interactions of Tc(IV) with humic substances

    SciTech Connect

    Boggs, M. A.; Minton, Travis; Lomasney, Samuel; Islam, Mohammed; Dong, Wenming; Gu, Baohua; Wall, Nathalie

    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.

  13. (99m)Tc-labeled therapeutic inhaled amikacin loaded liposomes.

    PubMed

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

    2013-12-01

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

  14. 99mTc-labeled Therapeutic Inhaled Amikacin Loaded Liposomes

    PubMed Central

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

    2014-01-01

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

  15. Lymphoscintigraphy in melanoma patients using Tc-99m dextran

    SciTech Connect

    Marciano, D.; Padgett, H.; Henze, E.; Carlson, C.; Bennett, L.R.

    1984-01-01

    Surgical removal of regional lymph nodes draining the site of a melanoma is a generally practiced procedure. It is often difficult in many cases of truncal melanomas near the midline or near the waistline to determine which group or groups of nodes to remove. Colloidal Au-198, Tc-99m sulfur colloid, and Tc-99m antimony sulfur colloid have all been used and have given useful clinical information. Objections, however, have been raised to the local radiation dose with these compounds. To reduce this problem while obtaining greater information on lymph flow, the authors have studied dextran, a macromolecule commonly used as plasma substitute. Dextran (average mol. wt. 72,000) labeled with Tc-99m has been used to study lymph drainage from the site of truncal melanoma in 29 patients. Serial images in the first hour following intradermal injection clearly demonstrate tracer in efferent lymphatics within 5 to 10 minutes, and brief pooling in the regional lymph nodes between 20 and 60 minutes. When compared with particulate tracers such as micro Tc-99m sulfur colloid, the Tc-99m dextran appears to move much faster through the lymphatics. Overall distribution of the Tc-99m dextran to lymph nodes is very similar to previous findings with micro Tc-99m sulfur colloid. Dextran drainage to more than one group of regional nodes was seen in 12/29 patients as compared with 17/50 patients using micro Tc-99m sulfur colloid. The superior images with Tc-99m dextran appear to make it the agent of choice.

  16. High -Tc superlight bipolarons in novel superconductors

    NASA Astrophysics Data System (ADS)

    Alexandrov, Sasha

    2003-03-01

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

  17. Measurements of the rf surface resistance of high- Tc superconductors

    SciTech Connect

    Delayen, J.R.; Bohn, C.L.; Roche, C.T.

    1990-01-01

    An experimental program is being conducted to assess the applicability of high-{Tc} superconductors for use in high power rf and microwave devices. The program involves the measurement of the rf surface resistance of high-{Tc} samples at frequencies between 0.15 and 40 GHz and rf surface magnetic fields as high as 640 gauss. Polycrystalline samples were found to have surface resistances which increase monotonically with rf-field amplitude, saturating at high field at a few percent of the normal-state surface resistance just above {Tc}. 13 refs., 2 figs., 1 tab.

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

    PubMed

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

    2012-01-11

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

  19. Unconventional high-Tc superconductivity in fullerides.

    PubMed

    Takabayashi, Yasuhiro; Prassides, Kosmas

    2016-09-13

    A3C60 molecular superconductors share a common electronic phase diagram with unconventional high-temperature superconductors such as the cuprates: superconductivity emerges from an antiferromagnetic strongly correlated Mott-insulating state upon tuning a parameter such as pressure (bandwidth control) accompanied by a dome-shaped dependence of the critical temperature, Tc However, unlike atom-based superconductors, the parent state from which superconductivity emerges solely by changing an electronic parameter-the overlap between the outer wave functions of the constituent molecules-is controlled by the C60 (3-) molecular electronic structure via the on-molecule Jahn-Teller effect influence of molecular geometry and spin state. Destruction of the parent Mott-Jahn-Teller state through chemical or physical pressurization yields an unconventional Jahn-Teller metal, where quasi-localized and itinerant electron behaviours coexist. Localized features gradually disappear with lattice contraction and conventional Fermi liquid behaviour is recovered. The nature of the underlying (correlated versus weak-coupling Bardeen-Cooper-Schrieffer theory) s-wave superconducting states mirrors the unconventional/conventional metal dichotomy: the highest superconducting critical temperature occurs at the crossover between Jahn-Teller and Fermi liquid metal when the Jahn-Teller distortion melts.This article is part of the themed issue 'Fullerenes: past, present and future, celebrating the 30th anniversary of Buckminster Fullerene'. PMID:27501971

  20. Pairing Fluctuations Above Tc: A Comparative Study

    NASA Astrophysics Data System (ADS)

    Verga, Simona; Gooding, Robert J.; Marsiglio, Frank

    2003-03-01

    Although the investigation of superconductivity in High Tc Cuprates has been extensive, its microscopic origin is still under debate. An important experimental fact is the universality of many properties of the cuprates (the low dimensionality, the d-wave symmetry of the superconducting gap and the pseudogap), which must be reproduced by any competitive theory. While there is no consensus about the 'glue' that binds two electrons in a pair, one can gain insight by simply providing it, without questioning its nature. The Attractive Hubbard Model for electrons on a lattice provides the means for such an approach, but even if it simplifies the picture considerably, in the coupling regime of interest one needs to rely on approximate theories. We present a comparative study of different versions of the T-matrix approximation in the atomic limit (strong coupling), where the existence of analytical solutions enables us to test how well the approximations work. We also employ a non-perturbative approach due to Y. M. Vilk and A.-M. S. Tremblay and compare it with the T-matrix and the analytical solutions. We discuss the relevance of such a study for other coupling regimes and more realistic models.

  1. 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.

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

    SciTech Connect

    Zachara, John M.; Kukkadapu, Ravi K.; Heald, Steve M.; McKinley, James P.; Dohnalkova, Alice C.; Fredrickson, James K.; Byong-Hun Jeon

    2006-04-05

    The overall project has been investigating the reactivity of pertechnetate [Tc(VII)] with Fe(II) forms in model mineral and mineral-microbe systems, and with sediments from the Oak Ridge FRC and the Hanford site. Past project results with Hanford and Oak Ridge sediments have been published in Fredrickson et al., (2004) and Kukkadapu et al., (2006). This poster summarizes a series of model system experiments that investigates whether microbes or biogenic Fe(II) were more important in the reduction of Tc(VII) in an anoxic suspension of ferrihydrite, Shewanella oneidensis MR-1, Tc(VII), and electron donor. Ferrihydrite is used to represent a bioavailable Fe(III) oxide present in small amounts in Oak Ridge and Hanford sediments. In order to address this overall goal, Tc(VII) reduction rates and redox products were studied in less complex systems where individual abiotic and biotic reactions were isolated for rigorous characterization. The specific objectives of the individual experiments in the series were as follows: (1) Identify the rates and products of the reaction of Tc(VII) with aqueous Fe(II) at circumneutral pH values (homogeneous reduction). (2) Identify the rates and products of the reaction of Tc(VII) with surface complexed Fe(II) on goethite and hematite in the circumneutral pH range (heterogeneous reduction). (3) Identify the rates and products of the reaction of Tc(VII) with MR-1 under anoxic conditions individually with hydrogen and lactate as electron donors (biologic reduction). (4) Use insights from the above experiments to determine which of the three above, potentially parallel reactions determine the final speciation of Tc in a mixture of ferrihydrite, respiring MR-1, and Tc(VII).

  3. [Diagnosis of achalasia using 99m-Tc pertechnetate scintigraphy].

    PubMed

    Mikosch, P; Gallowitsch, H J; Kresnik, E; Lind, P

    1997-06-01

    A 73-year-old patient presented a 99mTc scintiscan with a focal tracer accumulation left and caudal of the thyroid gland. Further investigations with sonography, CT, esophagoscopy and barium swallow provided the diagnosis of achalasia as the reason for focal 99mTc retention caudal of the thyroid gland. Explanation for 99mTc accumulation within the esophagus may be the nonspecific accumulation of 99mTc not only in the thyroid gland but also in the salivary glands. Excretion of the tracer follows with the saliva. Structural and motor disorders of the esophagus can thus lead to focal tracer retention within the esophagus simulating thyroid tissue. PMID:9395425

  4. Point nodes persisting far beyond Tc in Bi2212

    PubMed Central

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

    2015-01-01

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

  5. Getters for Tc and I Removal from Liquid Waste

    NASA Astrophysics Data System (ADS)

    Qafoku, N. P.; Asmussen, M.; Lawter, A.; Neeway, J.; Smith, G.

    2015-12-01

    A cementitious waste form, Cast Stone, is being evaluated as a possible supplemental waste form for the low activity waste (LAW) at the Hanford Site, which contains significant amounts of radioactive 99Tc and 129I, as part of the tank waste cleanup mission. To improve the retention of Tc and/or I in Cast Stone, materials with a high affinity for Tc and/or I, termed "getters," can be added to decrease the rate of contaminant release and diffusivity, and improve Cast Stone performance. A series of kinetic batch sorption experiments was performed to determine the effectiveness of the getter materials. Several Tc getters [blast furnace slag, Sn (II) apatite, SnCl2, nanoporous Sn phosphate, KMS-2 (a potassium-metal-sulfide), and Sn(II) hydroxyapatite] and I getters [layered Bi hydroxide, natural argentite mineral, synthetic argentite, Ag-impregnated carbon, and Ag-exchanged zeolite] were tested in different solution media, 18.2 MΩ DI H2O and a caustic LAW waste simulant containing 6.5 M Na or 7.8 M Na. The experiments were conducted at room temperature in the presence or absence of air. Results indicated that most Tc getters (with the exception of KMS-2) performed better in the DI H2O solution than in the 6.5 and 7.8 M Na LAW simulant. In addition, Tc sequestration may be affected by the presence of other redox sensitive elements that were present in the LAW simulant, such as Cr. The Tc getter materials have been examined through various solid-state characterization techniques such as XRD, SEM/EDS, XANES and EXAFS which provided evidence for plausible mechanisms of aqueous Tc removal. The results indicated that the Tc precipitates differ depending on the getter material and that Tc(VII) is reduced to Tc(IV) in most of the getters but to a differing extents. For the I getters, Ag-exchanged zeolite and synthetic argentite were the most effective ones. The other I getters showed limited effectiveness for sorbing I under the high ionic strength and caustic

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

    NASA Astrophysics Data System (ADS)

    Mausolf, Edward John

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

  7. 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.

  8. 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.

  9. Does [TcF(CO)5] exist? The crystal and molecular structure of [Tc(CO)3(OH)0.49F0.51]4·[Tc(CO)5(BF4)].

    PubMed

    Stepanova, E S; Gurzhiy, V V; Tyupina, M Yu; Miroslavov, A E; Sidorenko, G V; Lumpov, A A

    2016-05-17

    Technetium pentacarbonyl fluoride [TcF(CO)5] was prepared for the first time by reaction of [TcI(CO)5] with solid AgF in a dichloromethane solution at -23 °C. Low temperature crystallization of the resulting compound in a glass vial yielded an unusual complex [Tc(CO)3(OH)0.49F0.51]4·[Tc(CO)5(BF4)] characterized by single crystal XRD. PMID:27108652

  10. Proximity Effect at Graphene - High Tc Superconductor Junctions

    NASA Astrophysics Data System (ADS)

    Wang, Da; Shih, En-Min; Arefe, Ghidewon; Kim, Youngduck; Edelberg, Drew; Andrade, Erick; Wang, Dennis; Hone, James; Dean, Cory; Pasupathy, Abhay; Department of Physics, Columbia University, New York, NY 10027, USA Collaboration

    The proximity effect is a well-known mesoscopic phenomenon where Cooper pairs from a superconductor (S) enter into a normal metal (N) that is well coupled to it. Since graphene was discovered a decade ago, the proximity effect at superconductor-graphene junctions has been extensively studied and interesting phenomena such as specular Andreev reflection and ballistic transport at graphene Josephson junctions have been observed. However, superconductors used in these experiments to date are of conventional low Tc, such as aluminum(Tc=1.2K), NbSe2(Tc=7K), and MoRe(Tc=8K). Understanding how the proximity effect works between high-Tc superconductors (pnictides and cuprates) and the Dirac Fermions of graphene remains largely unexplored. The chief technical challenge here is to create high-quality junctions between high-Tc superconductors and graphene. In this work, we will introduce a home-made setup that allows us to exfoliate, transfer and encapsulate superconductor-graphene junctions in a well controlled inert atmosphere. Transport measurements of the proximity effect at graphene-iron pnictide(FeSe, FeTeSe) and graphene-cuprate(BSCCO) junctions will be described.

  11. Quasiparticle tunneling spectroscopy of high {Tc} cuprates

    SciTech Connect

    Zasadzinski, J.; Ozyuzer, L.; Yusof, Z.; Chen, J.; Gray, K.E.; Mogilevsky, R.; Hinks, D.G.; Cobb, J.L.; Markert, J.T.

    1996-04-01

    Superconductor-insulator-normal metal (SIN) and superconductor-insulator-superconductor (SIS) tunnel junctions provide important information on pairing state symmetry and mechanism. Measurements of such junctions on high {Tc} superconductors (HTS) are reported using mechanical point contacts, which generally display the optimum characteristics that can be obtained from HTS native-surface tunnel barriers. New tunneling data on the infinite-layer cuprate, Sr{sub 1{minus}x}Nd{sub x}CuO{sub 2} are reported which show a remarkable similarity to another electron-doped cuprate, Nd{sub 1.85}Ce{sub 0.85}CuO{sub 4}. In particular, there is a strong, asymmetric linear background conductance that is indicative of inelastic tunneling from a continuum of states. A discussion is given of the anomalous dip feature found in the tunneling and photoemission data on BSCCO 2212. It is shown that a similar feature is found in many cuprate junctions and that this dip scales with the gap energy over a wide range. New data on the single-layer, tetragonal cuprate, Tl{sub 2}Ba{sub 2}CuO{sub 6} (Tl2201) are presented and discussed in light of recent published results on the similar compound HgBa{sub 2}CuO{sub 4} (Hg1201). The HG1201 data display a low, flat sub-gap tunneling conductance which is consistent with a BCS density of states whereas the T12201 data display a cusp-like feature at zero bias which is more consistent with d{sub x}2-{sub y}2 symmetry.

  12. 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.

  13. 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.

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

    NASA Astrophysics Data System (ADS)

    Mazumdar, Chandan; Nagarajan, R.

    2015-07-01

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

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

    SciTech Connect

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

    2008-09-26

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

  16. Measurement of Tc distribution in Nb3Sn CICC

    NASA Astrophysics Data System (ADS)

    Calzolaio, Ciro; Bruzzone, Pierluigi; Uglietti, Davide

    2012-05-01

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

  17. 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.

  18. 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.

  19. Gap anisotropy and van Hove singularities in high {Tc} superconductors

    SciTech Connect

    Bok, J.; Bouvier, J.

    1996-12-31

    The authors compute the superconducting gap {Delta}{sub {rvec k}} using a simple band structure of the CuO{sub 2} planes in the high Tc materials. They suppose that for materials with doping corresponding to maximum {Tc}, the van Hove singularities lie close to the Fermi level as is confirmed by many photoemission experiments. They use a electron-photon interaction with weak screening, they find a strong gap anisotropy. For Bi 2212, {Delta} is maximum along the 100 and 010 directions with values between 20 and 30 meV and minimum along 110 with values between 0 and 10 meV. They use this anisotropic gap to compute the quasi-particle excitations density of states and the tunneling current-voltage I(V) characteristic for N-I-S and S-I-S junctions. This model agrees remarkably well with recent experiments of tunneling spectroscopy in high {Tc} cuprates.

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

    NASA Astrophysics Data System (ADS)

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

    2016-01-01

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

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

    SciTech Connect

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

    1985-05-01

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

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

    SciTech Connect

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

    1985-05-01

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

  3. The Tribolium chitin synthase genes TcCHS1 and TcCHS2 are specialized for synthesis of epidermal cuticle and midgut peritrophic matrix.

    PubMed

    Arakane, Y; Muthukrishnan, S; Kramer, K J; Specht, C A; Tomoyasu, Y; Lorenzen, M D; Kanost, M; Beeman, R W

    2005-10-01

    Functional analysis of the two chitin synthase genes, TcCHS1 and TcCHS2, in the red flour beetle, Tribolium castaneum, revealed unique and complementary roles for each gene. TcCHS1-specific RNA interference (RNAi) disrupted all three types of moult (larval-larval, larval-pupal and pupal-adult) and greatly reduced whole-body chitin content. Exon-specific RNAi showed that splice variant 8a of TcCHS1 was required for both the larval-pupal and pupal-adult moults, whereas splice variant 8b was required only for the latter. TcCHS2-specific RNAi had no effect on metamorphosis or on total body chitin content. However, RNAi-mediated down-regulation of TcCHS2, but not TcCHS1, led to cessation of feeding, a dramatic shrinkage in larval size and reduced chitin content in the midgut. PMID:16164601

  4. Fabrication Of High-Tc Superconducting Integrated Circuits

    NASA Technical Reports Server (NTRS)

    Bhasin, Kul B.; Warner, Joseph D.

    1992-01-01

    Microwave ring resonator fabricated to demonstrate process for fabrication of passive integrated circuits containing high-transition-temperature superconductors. Superconductors increase efficiencies of communication systems, particularly microwave communication systems, by reducing ohmic losses and dispersion of signals. Used to reduce sizes and masses and increase aiming accuracies and tracking speeds of millimeter-wavelength, electronically steerable antennas. High-Tc superconductors preferable for such applications because they operate at higher temperatures than low-Tc superconductors do, therefore, refrigeration systems needed to maintain superconductivity designed smaller and lighter and to consume less power.

  5. Thermomagnetic effects above and below {Tc} in the cuprate superconductors

    SciTech Connect

    Clayhold, J.A.; Xue, Y.Y.; Chu, C.W.; Eckstein, J.N.; Bozovic, I.

    1996-12-31

    Two different thermomagnetic transport quantities, the electrothermal conductivity and the Nernst effect are shown to be powerful probes of high-temperature superconductors. In the vortex state below {Tc}, the electrothermal conductivity is independent of both the magnetic field and the vortex viscosity because it is sensitive only to the properties of the vortex normal cores. Some new data from cuprate superconductors show a surprising, low-field anomaly in the dilute vortex limit. Above {Tc} in the normal state, it is shown how the Nernst effect is a probe of transport anisotropy around the Fermi surface.

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

    SciTech Connect

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

    2010-12-01

    CH2M HILL Plateau Remediation Company (CHPRC) is currently developing a 200-West Area groundwater pump-and-treat system as the remedial action selected under the Comprehensive Environmental Response, Compensation, and Liability Act Record of Decision for Operable Unit (OU) 200-ZP-1. This report documents the results of treatability tests Pacific Northwest National Laboratory researchers conducted to quantify the ability of selected activated carbon products (or carbons) to adsorb technetium-99 (Tc-99) from 200-West Area groundwater. The Tc-99 adsorption performance of seven activated carbons (J177601 Calgon Fitrasorb 400, J177606 Siemens AC1230AWC, J177609 Carbon Resources CR-1240-AW, J177611 General Carbon GC20X50, J177612 Norit GAC830, J177613 Norit GAC830, and J177617 Nucon LW1230) were evaluated using water from well 299-W19-36. Four of the best performing carbons (J177606 Siemens AC1230AWC, J177609 Carbon Resources CR-1240-AW, J177611 General Carbon GC20X50, and J177613 Norit GAC830) were selected for batch isotherm testing. The batch isotherm tests on four of the selected carbons indicated that under lower nitrate concentration conditions (382 mg/L), Kd values ranged from 6,000 to 20,000 mL/g. In comparison. Under higher nitrate (750 mg/L) conditions, there was a measureable decrease in Tc-99 adsorption with Kd values ranging from 3,000 to 7,000 mL/g. The adsorption data fit both the Langmuir and the Freundlich equations. Supplemental tests were conducted using the two carbons that demonstrated the highest adsorption capacity to resolve the issue of the best fit isotherm. These tests indicated that Langmuir isotherms provided the best fit for Tc-99 adsorption under low nitrate concentration conditions. At the design basis concentration of Tc 0.865 µg/L(14,700 pCi/L), the predicted Kd values from using Langmuir isotherm constants were 5,980 mL/g and 6,870 mL/g for for the two carbons. These Kd values did not meet the target Kd value of 9,000 mL/g. Tests

  7. 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

  8. [Complementary scintigraphic examinations (99mTc-MDP, 99mTc-MIBI and Octreoscan) in breast neoplasm assessment].

    PubMed

    Stefănescu, C; Chossiere, L; Rusu, V; Meignan, M

    1996-01-01

    Scintigraphic imagery was used in breast carcinoma mostly for the bone metastases screening, using 99mTc-MDP. Others radiopharmaceuticals can be used to visualize either the primary tumour or the soft tissues metastases. It's mainly the case of 99mTc-MIBI, and also of some somatostatin analogues, like Octreoscan. This case report of a patient with a T3N1M+ breast adenocarcinoma having different secondary sites represent also a prove of the complementarity of these explorations, which give the possibility of diagnostic and therapeutic evaluation and, in the same time, the possibility of a better understood of the metastasizing mechanism. PMID:9455458

  9. Magnetic localization limit in TC graded ferromagnetic thin films

    NASA Astrophysics Data System (ADS)

    Kirby, Brian; Fallarino, Lorenzo; Riego, Patricia; Pancaldi, Matteo; Berger, Andreas; Miller, Casey

    We have recently demonstrated that the effective Curie temperature (TC) of a ferromagnetic alloy thin film can be continuously varied as a function of depth via a corresponding compositional gradient. This work showed that the effective TC can be made to vary continuously over tens of nm. However, over a short enough distance, the system must become localized, with exchange coupling dominating the effects of the compositional gradient. Understanding this localization limit is important for potential applications, as it dictates the length-scale below which this technique stops being a viable engineering tool (at least for itinerant ferromagnets and their thermodynamic properties). To determine the localization limit in this class of system, we have fabricated a series of Co[1- x]Cr[ x] alloy alloy films, where x varies sinusoidally between 0.28 (nominal TC ~ 250 K) and 0.22 (TC > 300 K), and have used polarized neutron reflectometry to study samples of differing oscillation wavelength. These measurements confirm the desired sinusoidal pattern was achieved, and reveal the temperature-dependence of the magnetic depth profile. Results will be presented in the context of mean-field simulations.

  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. Lymphoscintigraphy with Tc-99m-labeled dextran

    SciTech Connect

    Henze, E.; Schelbert, H.R.; Collins, J.D.; Najafi, A.; Barrio, J.R.; Bennett, L.R.

    1982-10-01

    Current agents for lymphoscintigraphy have limitations because of slow migration of the colloidal tracer from the injection site and the unknown effect of phagocytosis on the removal of the labelled particles. The usefulness of Tc-99m dextran (TcDx) with a molecular weight of 110,000 has been tested for lymphoscintigraphy. Computer-assisted dynamic imaging and serial blood sampling in 13 dog experiments demonstrated that the tracer cleared only by lymph drainage from an interstitial injection site. Following interdigital injection of 1.0 ml (0.5-5.0 mCi), TcDx reached the knee or elbow lymph nodes in 12.4 +/- 6.5 (1 s.d.) sec, and the inguinal or axillary lymph nodes in 98.0 +/- 42.3 sec. It cleared from the injection site with a half-time of 31.5 min. In a dog with surgically induced lymphedema, tracer migration was markedly delayed in the edematous leg and the radionuclide lymphoscintigram resembled the contrast lymphangiogram. Initial studies in man yielded high-quality radionuclide lymphograms of the leg, and the pelvic and paraaortic lymph nodes. We concluded that TcDx is very promising for lymphoscintigraphy.

  12. Lymphoscintigraphy with Tc-99m-labeled dextran

    SciTech Connect

    Henze, E.; Schelbert, H.R.; Collins, J.D.; Najafi, A.; Barrio, J.R.; Bennett, L.R.

    1982-10-01

    Current agents for lymphoscintigraphy have limitations because of slow migration of the colloidal tracers from the injection site and the unknown effect of phagocytosis on the removal of the labeled particles. The usefulness of Tc-99m dextran (TcDx) with a molecular weight of 110,000 has been tested for lymphoscintigraphy. Computer-assisted dynamic imaging and serial blood sampling in 13 dog experiments demonstrated that the tracer cleared only by lymph drainage from an interstitial injection site. Following interdigital injection of 1.0 ml (0.5-5.0 mCi), TcDx reached the knee or elbow lymph nodes in 12.4 +/- 6.5 (1 s.d.) sec, and the inguinal or axillary lymph nodes in 98.0 +/- 42.3 sec. It cleared from the injection site with a half-time of 31.5 min. In a dog with surgically induced lymphedema, tracer migration was markedly delayed in the edematous leg and the radionuclide lymphoscintigram resembled the contrast lymphangiogram. Initial studies in man yielded high-quality radionuclide lymphograms of the leg, and the pelvic and paraaortic lymph nodes. We conclude that TcDx is very promising for lymphoscintigraphy.

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

    NASA Astrophysics Data System (ADS)

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

    2015-04-01

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

  14. /sup 99m/Tc dextran: a new blood-pool-labeling agent for radionuclide angiocardiography

    SciTech Connect

    Henze, E.; Robinson, G.D.; Kuhl, D.E.; Schelbert, H.R.

    1982-04-01

    We have explored the possibility of imaging the cardiac blood pool with dextran (Dx) labeled with /sup 99m/Tc (Tc) after Sn2+ reduction. Stannous dextran (SnDx) kits were prepared in advance and labeling was performed by adding /sup 99m/Tc. The labeling efficiency was greater than 95%. /sup 99m/Tc dextran (TcDx) was highly stable both in vivo and in vitro. In seven dogs we compared the quality of blood-pool images obtained with TcDx of different molecular weights (4 X 10(4) . Dx-40; 5 X 10(5) . Dx-500; 2 X 10(6) . Dx-2000) and with /sup 99m/Tc red blood cells (TcRBC) labeled in vitro, and determined the organ distribution of this new agent by whole-body scanning and blood sampling. TcDx provided high-quality cardiac blood-pool images up to 60 min after injection. The heart-to-lung ratios averaged 3.7 for TcDx-40, 3.9 for TcDx-500, and 5.4 for TcRBC at 60 min. Whereas TcDx-40 showed a relatively rapid initial urinary excretion and TcDx-2000 was degraded rapidly, TcDx-500 demonstrated the best kinetics for blood-pool imaging. Thus, TcDx is a new radiopharmaceutical with high labeling efficiency and stability. It overcomes a number of the limitations of currently used blood-labeling agents and may become useful for blood-pool imaging in man.

  15. 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.

  16. 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

  17. 77 FR 54908 - TC Offshore, LLC; Notice Establishing Deadline for Comments

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-06

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission TC Offshore, LLC; Notice Establishing Deadline for Comments On August 29, 2012, TC Offshore, LLC (TC Offshore) filed a response to the Commission's August 16, 2012 Data...

  18. Drug-induced modulation of Tc-99m pyrophosphate tissue distribution: what is involved

    SciTech Connect

    Wahner, H.W.; Dewanjee, M.K.

    1981-06-01

    More than ten years after their introduction, Tc-99m-labeled phosphates and phosphonates (TcP) continue to be of interest to the investigator and to hold promise for new clinical applications in the future. Initially, TcP compounds were valued because of their bone-seeking properties. Emphasis shifted from bone to soft tissue when Bonte et al. introduced Tc-99m-labeled pyrophosphate (TcPPi) for myocardial infarct scanning. Detailed information about TcPPi uptake in ischemic and necrotic myocardial tissue at the subcellular level has accumulated. Therefore, understanding of the mechanism of TcPPi uptake in infarcted myocardium is more detailed than understanding of uptake by bone. A new, and potentially powerful, approach to the use of TcP is being proposed by Carr et al. The authors attempt to modulate favorably the tissue distribution of TcPPi by prior administration of drugs in pharmacological quantities. The authors demonstrate that uptake of TcPPi can be enhanced in the necrotic myocardium, uptake by bone can be reduced, and the lesion-to-blood ratio can be altered favorably when vitamin D/sub 3/ or desoxycorticosterone acetate (DOCA) is administered in pharmacological doses before the TcPPi injection. A short review is presented of background information helpful for interpreting the drug effects on TcPPi uptake in bone or necrotic myocardial tissue.

  19. Discordant uptake of Tc-99m DTPA-galactosyl human serum albumin and Tc-99m Sn colloid in a patient with severe acute hepatitis.

    PubMed

    Miyazaki, C; Matsunaga, T; Kubo, K

    1994-08-01

    A patient with recently diagnosed severe acute hepatitis underwent serial liver scintigraphy with Tc-99m Sn colloid and Tc-99m DTPA-galactosyl human serum albumin. In initial studies, radionuclide distribution on Tc-99m DTPA-galactosyl human serum albumin scintigraphy was completely discrepant to that on Tc-99m Sn colloid scintigraphy. In a follow-up study 1 month later, the distribution of both radionuclides in the liver appeared relatively homogeneous. The uptake of Tc-99m DTPA-galactosyl human serum albumin and Tc-99m Sn colloid reflects the function of hepatocytes and Kupffer cells, respectively. Both kinds of scintigraphic study may be helpful to assess histopathologic change of different hepatic tissue architectures. PMID:7955747

  20. Tc-99m dextran: a new blood-pool-labeling agent for radionuclide angiocardiography

    SciTech Connect

    Henze, E.; Robinson, G.D.; Kuhl, D.E.; Schelbert, H.R.

    1982-04-01

    We have explored the possibility of imaging the cadiac blood pool with dextran (Dx) labeled with Tc-99m (Tc) after Sn/sup 2 +/ reduction. Stannous dextrane (SnDx) kits were prepared in advance and labeling was performed by adding Tc-99m. The labeling efficiency was greater than 95%. Technetium-99m dextran (TcDx) was highly stable both in vivo and in vitro. In seven dogs we compared the quality of blood-pool images obtained with TcDx of different molecular weights ( 4 x 10/sup 4/ = Dx-40; 5 x 10/sup 5/ = Dx-500; 1 x 10/sup 6/ = Dx-2000) and with Tc-99m red blood cells (TcRBC) labeled in vitro, and determined the organ distribution of this new agent by whole-body scanning and blood sampling. TcDx provided high-quality cardiac blood-pool images up to 60 min after injection. The heart-to-lung ratios averaged 3.7 for TcDx-40, 3.9 for TcDx-500, and 5.4 for TcRBC at 60 min. Whereas TcDx-40 showed a relatively rapid initial urinary excretion and TcDx-2000 was degraded rapidly, TcDx-500 demonstrated the best kinetics for blood-pool imaging. Thus, TcDx is a new radiopharmaceutical with high labeling efficiency and stability. It overcomes a number of the limitations of currently used blood-labeling agents and may become useful for blood-pool imaging in man.

  1. CD3+CD8+CD161high Tc17 cells are depleted in HIV-infection.

    PubMed

    Gaardbo, Julie Christine; Hartling, Hans Jakob; Thorsteinsson, Kristina; Ullum, Henrik; Nielsen, Susanne Dam

    2013-02-20

    CD8 Tc17 cells with pro-inflammatory properties have only recently been acknowledged, and Tc17 cells in HIV-infection are not described. CD3CD8CD161 Tc17 cells and the production of interleukin (IL)-17 were examined in untreated and treated HIV-infected patients, HIV-hepatitis C virus co-infected patients, and healthy controls. Depletion of CD3CD8CD161 Tc17 cells and diminished production of IL-17 in HIV-infected patients were found. The level of Tc17 cells was associated with the CD4 cell count in treated patients. PMID:23135168

  2. First report of human Trypanosoma cruzi infection attributed to TcBat genotype.

    PubMed

    Ramírez, J D; Hernández, C; Montilla, M; Zambrano, P; Flórez, A C; Parra, E; Cucunubá, Z M

    2014-11-01

    Chagas disease is an endemic disease of the American continent caused by Trypanosoma cruzi and divided into six discrete typing units (TcI - TcVI). Nearly 10 million people harbour the infection representing a serious issue in public health. Epidemiological surveillance allowed us to detect a bat-related T. cruzi genotype (henceforth named TcBat) in a 5-year-old female living in a forest area in northwestern Colombia. Molecular tools determined a mixed infection of T. cruzi I and TcBat genotypes. This represents the first report of TcBat infection in humans; the epidemiological consequences of this finding are discussed herein. PMID:25285940

  3. Near constancy of the pressure dependence of Tc across families of organic and fullerene superconductors

    NASA Astrophysics Data System (ADS)

    Crespi, Vincent H.; Cohen, Marvin L.

    1996-01-01

    Pressure strongly depresses the superconducting transition temperature Tc of both the doped fullerenes and the β-ET[(BEDT-TTF)nXm, (BEDT-TTF)=bis(ethylenedithio)tetrathiofulvalene)] organic superconductors. An outstanding puzzle in these materials is the weak variation dTc/dP across families of compounds with large variations in Tc. This property has been used to argue against phonon-induced pairing. However, closer examination of the volume dependence of Tc reveals that the weak variation of dTc/dP is consistent with moderate (but not weak) electron-phonon coupling.

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

    DOEpatents

    Schlenga, Klaus; de Souza, Ricardo E.; Wong-Foy, Annjoe; Clarke, John; Pines, Alexander

    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.

  5. The unconventional electrodynamics of high {Tc} and organic superconductors

    SciTech Connect

    Timusk, T.; Cao, N.; Basov, D.N.; Homes, C.C.

    1996-12-31

    The combination of lowered dimensionality and electron-electron correlations are responsible for the unusual temperature and frequency dependence of the electrical conductivity of the new superconductors. The authors first review the electrodynamics of two systems, U{sub 2}Ru{sub 2}Si{sub 2} and Sr{sub 2}RuO{sub 4} where conventional Fermi liquid ideas seem to work. Here transport is by free carriers with strongly renormalized masses. On the other hand the electrodynamics of the high {Tc} cuprates and the organic charge transfer salts is unconventional. The high {Tc}`s show a Drude peak with an anomalous temperature and frequency dependent scattering rate for the in-plane conductivity, while normal to the planes they are almost insulating. In the organics, the transport currents are carried by a narrow collective mode coupled to phonons. 44 refs., 7 figs.

  6. Fluxoid motion and resistive transition in high Tc superconductors

    NASA Astrophysics Data System (ADS)

    Matsushita, T.; Ni, B.

    1990-07-01

    Significantly broad resistive transition has been observed in high-Tc superconductors under a magnetic field. A similar broad transition was observed by French et al. (1967) in resistance versus magnetic field characteristics in low-temperature superconductors for various current densities. In this case, the critical current density and the flow resistivity completely determine the overall resistive characteristics. This suggests that the resistive characteristics in high-Tc superconductors may also be determined by these two quantities alone. In fact, the procedure outlined reproduces the commonly observed resistive characteristics. A notable feature determined from this procedure is that a knee exists in the resistance versus temperature curve. This projection corresponds to the irreversibility point; i.e. the temperature at which the critical current density is reduced to zero.

  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. Bone metastasis on Tc99-m sestamibi myocardial perfusion scan

    PubMed Central

    Hatemi, Lachin; Jabi, Feraas

    2015-01-01

    A 75-year-old woman presented to our department for a stress myocardial perfusion imaging study with Tc99m-sestamibi. Incidental focal uptake, found in the left upper anterior chest, was initially felt to be located in the left breast. After additional single-photon CT imaging was performed the same day, extracardiac foci within the ribs, spine, and left lung (worrisome for active metastases) were shown to be present, with the initial focus located within a left rib rather than a breast. A review of previous radiographic and nuclear imaging studies confirmed metastatic disease from recurrent follicular thyroid cancer. Atypical focal extracardiac activity must be closely scrutinized for the possibility of malignancy, as Tc99m-sestamibi (in addition to being myocardium-avid) is tumor-avid.

  9. 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.

  10. 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.

  11. 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.

  12. Raman scattering in high-{Tc} superconductors: Electronic excitations

    SciTech Connect

    Cardona, M.; Strohm, T.; Kircher, J.

    1996-12-31

    Since the discovery of the high {Tc} superconductors Raman scattering has proven to be an excellent technique to characterize them and to investigate basic physical properties relevant to the elusive mechanism responsible for their superconductivity. The authors discuss here several aspects of the technique as applied to superconductivity, including scattering by lattice vibrations, magnetic excitations, and electronic excitations, with particular emphasis on the latter, both in the normal and the superconducting state. 47 refs., 8 figs., 1 tab.

  13. 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.

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

    SciTech Connect

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

    1981-04-01

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

  15. 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.

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

    SciTech Connect

    Maiti, Moumita; Lahiri, Susanta

    2010-02-15

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

  17. Collective band structures in the 99Tc nucleus

    NASA Astrophysics Data System (ADS)

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

    2015-05-01

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

  18. Optimal High-TC Superconductivity in Cs3C60

    NASA Astrophysics Data System (ADS)

    Harshman, Dale; Fiory, Anthony

    The highest superconducting transition temperatures in the (A1-xBx)3C60 superconducting family are seen in the A15 and FCC structural phases of Cs3C60 (optimized under hydrostatic pressure), exhibiting measured values for near-stoichiometric samples of TC0 meas . = 37.8 K and 35.7 K, respectively. It is argued these two Cs-intercalated C60 compounds represent the optimal materials of their respective structures, with superconductivity originating from Coulombic e- h interactions between the C60 molecules, which host the n-type superconductivity, and mediating holes associated with the Cs cations. A variation of the interlayer Coulombic pairing model [Harshman and Fiory, J. Supercond. Nov. Magn. 28 ̲, 2967 (2015), and references therein] is introduced in which TC0 calc . ~ 1 / lζ , where l relates to the mean spacing between interacting charges on surfaces of the C60 molecules, and ζ is the average radial distance between the surface of the C60 molecules and the neighboring Cs cations. For stoichiometric Cs3C60, TC0 calc . = 38.08 K and 35.67 K for the A15 and FCC macrostructures, respectively; the dichotomy is attributable to differences in ζ.

  19. 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.

  20. Identification of Liquids by High-Tc Josephson THz Detectors

    NASA Astrophysics Data System (ADS)

    Divin, Y.; Lyatti, M.; Poppe, U.; Urban, K.

    Fast and reliable detection of liquids will be required for future checkpoint screening techniques. Recently, a new electromagnetic-wave concept based on our high-Tc Josephson detectors and Hilbert spectroscopy has been suggested to distinguish between liquids. This technology covers a spectral range of main dispersions of liquids, from a few GHz to a few THz, and thus significantly enhances reliability of identification. The high-Tc detectors, due to a power dynamic range of more than five orders, might guarantee short identification times. Several demonstration set-ups of liquid identifiers, consisting of high-Tc Josephson detectors, integrated in Stirling coolers, and polychromatic radiation sources, have been developed and characterized. Reflection polychromatic spectra of various liquids in plastic containers have been measured at the spectral range of 15-500 GHz with total scanning time down to 0.2 second. Reliable identification of liquids, both benign and threat, within an accuracy of 0.3% was demonstrated using water as a reflectance reference. The reflectance values for 30%H2O2/H2O solution at frequencies of 30 and 100 GHz were practically undistinguishable from that of for pure water, but an increase of the relative reflectance from 1.017 at 282 GHz to 1.033 at 434 GHz has been found. Last circumstance will be used for optimization of the identifiers.

  1. High- Tc superconductor characteristics control by ion implantation

    NASA Astrophysics Data System (ADS)

    Matsui, S.; Matsutera, H.; Yoshitake, T.; Fujita, J.; Satoh, T.

    1989-03-01

    Transition temperature ( Tc) control and annealing effects of YBa 2Cu 3O x and Bi 2Sr 1.4 Ca 1.8Cu 2.2O y superconductor thin films implanted by 200 keV Ne + have been investigated. YBa 2Cu 3 O xTc end points for 0, 1 × 10 14, 1 × 10 15 and 1 × 10 16 ions/cm 2 doses are 75, 71, 62 and 16 K, respectively. On the other hand, Bi 2Sr 1.4Ca 1.8Cu 2.2O y, Tc end points for 0, 1 × 10 12 and 1 × 10 13 ions/cm 2 doses are 78, 76 and 54 K, respectively, c lattice constant increases were observed for the implanted films. It is confirmed that the superconducting characteristics for films, are recovered by anneaing in O 2 atomosphere. Moreover, microcrystal growth caused by annealing the implanted YBa 2Cu 3O x film was observed on the surface.

  2. 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.

  3. The spin-polaron theory of high-Tc superconductivity

    NASA Astrophysics Data System (ADS)

    Mott, N. F.

    1990-01-01

    An outline is given of the model for some high-temperature superconductors which assumes that the carriers are holes in the (hybridized) oxygen 2p band and form ‘spin polarons’ with the moments on the copper atoms. A comparison is made with observations of spin polarons in Gd3-xvxS4 and with the properties of La1-xSrxVO3 in relation to those of La2-xSrxCuO4. It is assumed, following several authors, that in the superconductors the polarons form bipolarons, which are bosons, and a comparison is made with some other treatments of this hypothesis. It is proposed that in many such superconductors the boson, essentially a pair of these holes, moves in an impurity band, and that normally all the polarons (fermions) form bipolarons; the fermions repel each other on the same site (positive Hubbard U) but attract when on adjacent sites; the critical temperature Tc is then that at which the Bose gas becomes non-degenerate. In such materials a non-degenerate gas of bosons would carry the current above Tc as first suggested by Alexandrov et al. (1986). The linear increase in the resistivity above Tc is explained on this hypothesis. The effective mass of the bipolaron is, we believe, large (˜20 30me). The copper 3d9 moments in the superconducting range resonate between their two orientations as a consequence of the motion of the carriers, as they do in the description by Brinkman and Rice (1970) of highly correlated metals. Spin polarons, we believe, form only when this is so, but not in the antiferromagnetic range of x. A discussion is given of the resistivity above Tc, thermopower above Tc, and of the nature of the superconducting gap as shown by tunnelling. We confine our discussion to the materials containing copper, excluding for instance cubic Ba1-xKxBiO3, and possibly any superconductor containing bismuth, where the bosons may be Bi3+.

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

    PubMed

    Yu, B F

    1988-07-01

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

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

    SciTech Connect

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

    1984-01-01

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

  6. Gallbladder Activity on 99mTc-Labeled Red Cell Scintigraphy Confirmed by SPECT/CT Imaging.

    PubMed

    Wang, Ling; Jing, Hongli; Chen, Libo; Wang, Zhenghua; Li, Fang

    2016-09-01

    Tc-labeled red cell (Tc-RBC) scintigraphy is commonly used to detect gastrointestinal bleeding. Gallbladder visualization on Tc-RBC scintigraphy is not common. We present a case of gallbladder visualization on Tc-RBC scintigraphy confirmed by SPECT/CT imaging in a patient with chronic renal failure and anemia. PMID:27405034

  7. 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.

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

    PubMed

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

    2015-05-01

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

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

    PubMed Central

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

    2015-01-01

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

  10. Peripheral Tc17 and Tc17/Interferon-γ Cells are Increased and Associated with Lung Function in Patients with Chronic Obstructive Pulmonary Disease

    PubMed Central

    Xu, Wei-Han; Hu, Xiao-Ling; Liu, Xiao-Fang; Bai, Peng; Sun, Yong-Chang

    2016-01-01

    Background: Chronic obstructive pulmonary disease (COPD) is characterized by progressive loss of lung function and local and systemic inflammation, in which CD8+ T-cells are believed to play a key role. Activated CD8+ T-cells differentiate into distinct subpopulations, including interferon-γ (IFN-γ)-producing Tc1 and interleukin (IL)-17-producing Tc17 cells. Recent evidence indicates that Tc17 cells exhibit considerable plasticity and may convert into IL-17/IFN-γ-double producing (Tc17/IFN-γ) cells when driven by inflammatory conditions. The aim of this study was to investigate the Tc17/IFN-γ subpopulation in peripheral blood of patients with COPD and to evaluate their potential roles in this disease. Methods: Peripheral blood samples were collected from 15 never-smokers, 23 smokers with normal lung function, and 25 patients with COPD (Global Initiative for Chronic Obstructive Lung Disease 2–4). Proportions of the IL-17/IFN-γ-double expressing subpopulation were assessed using flow cytometry. Plasma concentrations of cytokines favoring Tc17/IFN-γ differentiation were measured by enzyme-linked immunosorbent assay. Results: Patients with COPD had higher proportions of Tc17 cells and Tc17/IFN-γ cells in the peripheral blood than smokers and never-smokers. The plasticity of Tc17 cells was higher than that of Th17 cells. The percentages of Tc17 cells and Tc17/IFN-γ cells showed negative correlations with forced expiratory volume in 1 s % predicted value (r = −0.418, P = 0.03; r = −0.596, P = 0.002, respectively). The plasma concentrations of IL-6, transforming growth factor-β1, and IL-12 were significantly higher in patients with COPD compared with smokers and never-smokers. Conclusions: Peripheral Tc17 cells are increased and more likely to convert to Tc17/IFN-γ cells in COPD, suggesting that Tc17 cell plasticity may be involved in persistent inflammation of the disease. PMID:27064034

  11. Committed Tc17 cells are phenotypically and functionally resistant to the effects of IL-27.

    PubMed

    El-Behi, Mohamed; Dai, Hong; Magalhaes, Joao G; Hwang, Daniel; Zhang, Guang-Xian; Rostami, Abdolmohamad; Ciric, Bogoljub

    2014-10-01

    IL-17-secreting CD8(+) T cells (Tc17 cells) have been implicated in immunity to infections, cancer, and autoimmune diseases. Thus far, studies on Tc17 cells have primarily investigated their development from naïve precursors, while the biology of committed Tc17 cells has been less characterized, in particular during the effector phase of immune responses. IL-27 is an important regulator of inflammation through the induction of regulatory Tr1 cells, as well as a suppressor of Th17-cell development. IL-27 suppresses the development of Tc17 cells, but its effects on committed Tc17 cells are unknown. Here we demonstrate that even though IL-27 completely inhibited the development of C57BL/6 mouse Tc17 cells, it had little effect on previously committed Tc17 cells. Although committed Tc17 cells were capable of responding to IL-27, it had no effect on expression of RORγt and RORα, or production of various cytokines. Committed Tc17 cells did not express granzyme B and lacked cytotoxicity in vitro, features that remained unaltered by IL-27 treatment. Nonetheless, they efficiently induced diabetes, irrespective of treatment with IL-27 prior to transfer into RIP-mOVA mice. These findings suggest that use of IL-27 to modulate autoimmune diseases might have limited therapeutic efficacy if autoaggressive Tc17 cells have already developed. PMID:25070084

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

    SciTech Connect

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

    2007-07-01

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

  13. Tissular distributions and kinetics of two renal 99mTc-radiopharmaceuticals in rat.

    PubMed

    Bonnin, F; Petiet, A; Petegnief, Y; Colas-Linhart, N; Bok, B

    2001-05-01

    A digital radioimager (RI), conventional radioautography (RA), and tracks microradioautography (MRA) were used to assess the biodistributions and kinetics of 99mTc-dimercaptosuccinic (99mTc-DMSA) and 99mTc-mercaptoacetyltriglycine (99mTc-MAG3) in rat at both macroscopic and microscopic levels. Three groups of male Wistar rats were studied. Using gamma-counting, kidney, liver, spleen and blood kinetics of both tracers were assessed in the three groups. Using RA and RI, renal slices were analyzed in group 1 the animals being sacrified from 2 to 60 min after injection of 99mTc-MAG3, and in group 2 the animals being sacrificed from 0.5 to 24 hr after injection of 99mTc-DMSA. Using MRA, renal slices were analyzed for 99mTc-DMSA (group 3). RA films and RI images displayed the variation with time of the cortical and medullary uptakes of the tracers. No regional heterogeneity within the different structures could be seen neither with RA films nor with MRA. The remaining activity in the blood 24 hr after injection of 99mTc-DMSA was evaluated. The tissular distributions of both tracer being homogenous, mean values of cortical uptake seems to be acceptable for dosimetric studies. Our results incite to use of 99mTc-MAG3 instead of 99mTc-DMSA when both tracers may be indicated. PMID:11441950

  14. High-pressure studies on Tc and crystal structure of iron chalcogenide superconductors

    NASA Astrophysics Data System (ADS)

    Takahashi, Hiroki; Tomita, Takahiro; Takahashi, Hiroyuki; Mizuguchi, Yoshikazu; Takano, Yoshihiko; Nakano, Satoshi; Matsubayashi, Kazuyuki; Uwatoko, Yoshiya

    2012-10-01

    The superconducting transition temperature, Tc, in iron-based solids can be enhanced by applied pressure: Tc increases from 8 to 37 K for the 11-type FeSe when the pressure is raised from 0 to 4 GPa. High-pressure studies can elucidate the mechanism of superconductivity in such novel materials. In this paper, we present a high-pressure study of Fe(Se1-xTex) and Fe(Se1-xSx). In the case of Fe(Se1-xTex), the maximum Tc under high pressure did not exceed the Tc of FeSe, which can be attributed to the structural transition to the monoclinic phase. For Fe(Se1-xSx) (0 < x < 0.3), Tc exhibited a significant increase with pressure; however, the maximum Tc under high pressure did not exceed the Tc of FeSe. This may be due to the disorder induced by substituting S for Se, which is similar to the pressure effect on Tc for the 1111-type superconductor Ca(Fe1-xCox)AsF. The Tc of Fe(Se1-xSx) showed a complex behavior below 1 GPa, first decreasing and then increasing with increasing pressure. From high-pressure x-ray diffraction measurements, the Tc (P) curve was correlated with the local structural parameter.

  15. Evolution of NADPH-cytochrome P450 oxidoreductases (POR) in Apiales - POR 1 is missing.

    PubMed

    Andersen, Trine Bundgaard; Hansen, Niels Bjørn; Laursen, Tomas; Weitzel, Corinna; Simonsen, Henrik Toft

    2016-05-01

    The NADPH-dependent cytochrome P450 oxidoreductase (POR) is the obligate electron donor to eukaryotic microsomal cytochromes P450 enzymes. The number of PORs within plant species is limited to one to four isoforms, with the most common being two PORs per plant. These enzymes provide electrons to a huge number of different cytochromes P450s (from 50 to several hundred within one plant). Within the eudicotyledons, PORs can be divided into two major clades, POR 1 and POR 2. Based on our own sequencing analysis and publicly available data, we have identified 45 PORs from the angiosperm order Apiales. These were subjected to a phylogenetic analysis along with 237 other publicly available (NCBI and oneKP) POR sequences found within the clade Asterids. Here, we show that the order Apiales only harbor members of the POR 2 clade, which are further divided into two distinct subclades. This is in contrast to most other eudicotyledon orders that have both POR 1 and POR 2. This suggests that through gene duplications and one gene deletion, Apiales only contain members of the POR 2 clade. Three POR 2 isoforms from Thapsia garganica L., Apiaceae, were all full-length in an Illumina root transcriptome dataset (available from the SRA at NCBI). All three genes were shown to be functional upon reconstitution into nanodiscs, confirming that none of the isoforms are pseudogenes. PMID:26854662

  16. Aspects of nodal quasiparticle transport in high-Tc superconductors

    NASA Astrophysics Data System (ADS)

    Smith, Michael F.

    Various low-temperature thermodynamic and transport properties of high TC superconductors at temperatures well below TC are studied theoretically under the assumption that the low-energy excited states can be regarded as independent Bogolubov quasiparticles near the nodes of the superconducting order parameter. In the limiting case of temperatures well above that corresponding to the impurity scattering rate, a Boltzmann-equation description of the quasiparticle distribution is used to study thermal and electrical transport for several scattering mechanisms. In particular, the dominant scattering mechanism for the relaxation of microwave electrical currents well below TC is identified, and the observed temperature dependence of the microwave conductivity data in optimally-doped YBa2Cu3O7-delta thus explained. The Knight shift and nuclear spin relaxation rate at temperatures well above the impurity scattering rate are also calculated and compared with available data. In the opposite limiting case of temperatures well below that corresponding to the impurity scattering rate, the sound attenuation and electron-phonon heat transfer rate are calculated. A model for the electron-phonon interaction in square-lattice tight-binding materials is developed and used to explain the huge measured anisotropy of the normal-state sound attenuation in the unconventional superconductor Sr2RuO4 and to rule out certain candidates for the order parameter symmetry of this material. A calculation of the electron-phonon heat transfer rate for d-wave superconductors gives the dependence of this quantity on various material parameters. Finally, the result for the electron-phonon heat transfer rate is used to explain the origin of the anomalous downturns in the thermal conductivity that have been observed in both the normal and superconducting state of cuprate superconductors, most notably in Pr2-xCe xCuO7-delta.

  17. Portable exhauster POR-007/Skid E and POR-008/Skid F storage plan

    SciTech Connect

    Nelson, O.D.

    1998-07-25

    This document provides storage requirements for 1,000 CFM portable exhausters POR-O07/Skid E and POR-008/Skid F. These requirements are presented in three parts: preparation for storage, storage maintenance and testing, and retrieval from storage. The exhauster component identification numbers listed in this document contain the prefix POR-007 or POR-008 depending on which exhauster is being used.

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

    SciTech Connect

    Suenaga, Masaki

    1998-11-01

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

  19. Ultrafast IR detector response in high Tc superconducting thin films

    NASA Technical Reports Server (NTRS)

    Lindgren, Mikael; Ahlberg, Henrik; Danerud, Martin; Larsson, Anders; Eng, Sverre T.

    1991-01-01

    The response from a high Tc superconducting multielement optical detector made of a laser deposited Y-Ba-Cu-O thin film has been evaluated. Several microscopic and spectroscopic techniques were used to establish the presence of the correct phase of the thin film. Optical pulses from a laser diode at 830 nm and from a Q-switched CO2-laser at 10.6 microns were used. The detector responded to 50 ps (FWHM) pulses. A comparison between dR/dT of the film and the response amplitude as a function of temperature indicated a bolometric response.

  20. 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

  1. Considerations of acidifying water samples for 99Tc analysis.

    PubMed

    Blanchard, R L; Lieberman, R; Richardson, W S; Wakamo, C L

    1993-08-01

    Environmental water samples are routinely acidified before radionuclide analysis to prevent adsorption of radionuclides on the container walls. This study addresses the concern for volatilizing 99Tc from acid solutions during evaporation before beta analysis has been addressed. Water samples can be acidified to pH 1.7 with nitric acid and evaporated to dryness on planchets without significant losses of technetium due to volatilization. However, the planchets should not be flamed unless a detergent is used, and control samples should be flamed to determine the loss of activity under the conditions used. PMID:8392504

  2. Isospin symmetry breaking in 93Tc and statistical properties

    NASA Astrophysics Data System (ADS)

    Åberg, S.; Heine, A.; Mitchell, G. E.; Richter, A.

    2004-09-01

    We present a statistical analysis of proton resonances in the compound nucleus 93Tc in terms of random matrix theory (RMT). The fluctuation properties of energy levels and reduced widths from data measured by Bilpuch et al. [Phys. Rev. C 9 (1974) 1589] are studied. We conclude that one T> = 9 / 2 isobaric analog state does not affect the spectral correlations of a sequence of 124 T< = 7 / 2 states, and that the observed deviations from RMT are due to unobserved levels. For the reduced widths, however, certain deviations from Porter-Thomas statistics are attributed to the effect of isospin mixing.

  3. 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

  4. Applications using high-Tc superconducting terahertz emitters

    PubMed Central

    Nakade, Kurama; Kashiwagi, Takanari; Saiwai, Yoshihiko; Minami, Hidetoshi; Yamamoto, Takashi; Klemm, Richard A.; Kadowaki, Kazuo

    2016-01-01

    Using recently-developed THz emitters constructed from single crystals of the high-Tc superconductor Bi2Sr2CaCu2O8+δ, we performed three prototype tests of the devices to demonstrate their unique characteristic properties for various practical applications. The first is a compact and simple transmission type of THz imaging system using a Stirling cryocooler. The second is a high-resolution Michelson interferometer used as a phase-sensitive reflection-type imaging system. The third is a system with precise temperature control to measure the liquid absorption coefficient. The detailed characteristics of these systems are discussed. PMID:26983905

  5. Applications using high-Tc superconducting terahertz emitters

    NASA Astrophysics Data System (ADS)

    Nakade, Kurama; Kashiwagi, Takanari; Saiwai, Yoshihiko; Minami, Hidetoshi; Yamamoto, Takashi; Klemm, Richard A.; Kadowaki, Kazuo

    2016-03-01

    Using recently-developed THz emitters constructed from single crystals of the high-Tc superconductor Bi2Sr2CaCu2O8+δ, we performed three prototype tests of the devices to demonstrate their unique characteristic properties for various practical applications. The first is a compact and simple transmission type of THz imaging system using a Stirling cryocooler. The second is a high-resolution Michelson interferometer used as a phase-sensitive reflection-type imaging system. The third is a system with precise temperature control to measure the liquid absorption coefficient. The detailed characteristics of these systems are discussed.

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

    SciTech Connect

    Cataldo, D.A.; Garland, T.R.; Wildung, R.E.; Fellows, R.J. )

    1989-08-01

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

  7. {Tc(NO)(Cp)(PPh3)}(+) - a novel technetium(i) core.

    PubMed

    Ackermann, J; Hagenbach, A; Abram, U

    2016-08-11

    Reactions between [Tc(I)(NO)X2(PPh3)2(CH3CN)] complexes (X = Cl, Br) and KCp form the pseudotetrahedral organotechnetium compounds [Tc(I)(NO)(Cp)(PPh3)X]. The halide ligands can readily be replaced by other halides or organometallic ligands giving access to a novel family of technetium(i) compounds with the robust {Tc(NO)(Cp)(PPh3)}(+) core. PMID:27470912

  8. Diagnosis of orbital cavernous hemangioma with Tc-99m RBC SPECT.

    PubMed

    Ki, W W; Shin, J W; Won, K S; Ryu, J S; Yang, S O; Lee, H K; Kim, Y J

    1997-08-01

    The authors report two cases of orbital cavernous hemangioma diagnosed by Tc-99m RBC SPECT. Tc-99m RBC SPECT showed a typical scintigraphic pattern commonly seen in hepatic hemangioma in which there is intense focally increased uptake on delayed SPECT images. Tc-99m RBC SPECT in orbital cavernous hemangioma may be as useful a diagnostic modality as in hepatic hemangioma. PMID:9262901

  9. Purification of the Yersinia entomophaga Yen-TC Toxin Complex Using Size Exclusion Chromatography.

    PubMed

    Jones, Sandra A; Hurst, Mark R H

    2016-01-01

    The Yersinia entomophaga toxin complex (Yen-TC) is the bacterium's main virulence determinant. Because of its high insect activity, methods were developed to allow the routine isolation and purification of Yen-TC from an overnight bacterial culture using size exclusion chromatography. Here we outline an overnight purification procedure using a 100-ml culture volume, where approximately 2 mg of Yen-TC, with an approximate purity of 95-98 %, can be routinely obtained. PMID:27565490

  10. Structural (EXAFS) and solution equilibrium studies on the oxotechnetium(V) complexes TcOX/sub 4//sup -/ and TcOX/sub 5//sup 2 -/ (X = Cl, Br)

    SciTech Connect

    Thomas, R.W.; Heeg, M.J.; Elder, R.C.; Deutsch, E.

    1985-05-08

    The equilibrium between the technetium(V) complexes TcOCl/sub 4//sup -/ and TcOCl/sub 5//sup 2 -/ has been investigated in 12 M HCl and in CH/sub 2/Cl/sub 2/ solutions by Raman spectroscopy. In both media the five-coordinate complex is the predominant species, but in the aqueous medium water competes for the sixth coordination site and causes formation of the six-coordinate TcOCl/sub 5//sup 2 -/ anion to be even less favorable. Rate constants for the reaction are given. Procedures are described for generating good yields of either TcOX/sub 4//sup -/ or TcOX/sub 5//sup 2 -/ (X = Cl, Br) salts from the same reaction mixture. The complexes TcOCl/sub 4//sup -/, TcOCl/sub 5//sup 2 -/, TcOBr/sub 4//sup -/, TcOBr/sub 5//sup 2 -/, and TcI/sub 6//sup 2 -/ have been structurally characterized by EXAFS techniques. Observed Tc=O and Tc-X bond lengths are consistent with the known dependence of bond length on coordination number, the established structural trans effect induced by the Tc=O linkage, and existing crystallographic data on TcOCl/sub 4//sup -/ and related molybdenum(V) complexes.

  11. 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.

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

    SciTech Connect

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

    1985-07-03

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

  13. Standard Model for Superconductivity in Graphite Intercalation Compounds: Prediction of Optimum Tc

    NASA Astrophysics Data System (ADS)

    Takada, Yasutami

    2009-03-01

    Based on the model that was successfully applied to the explanation of superconductivity with the transition temperature Tc of about 0.1K or less in the alkali- intercalated graphite compounds such as KC8, RbC8, and CsC8 in 1982 [Y. Takada, J. Phys. Soc. Jpn. 51, 63 (1982) ], we have calculated Tc for the alkaline-earth- intercalated graphite compounds including CaC6, YbC6, and SrC6 with Tc of about 10K or less to find that the same model reproduces the observed Tc in those compounds as well, indicating that it is a standard model for superconductivity in the graphite intercalation compounds with Tc ranging over three orders of magnitude. The difference in Tc by two orders between KC8 and CaC6 can be accounted for by (i) doubling Z the valency of the metal ions, which enhances Tc by one order, and (ii) tripling m^* the effective mass of the superconducting three-dimensional electrons in the interlayer band, which also enhances Tc by one order. Enhancement of Tc well beyond 10 K is also predicted in this model, if intercalant metals are judiciously chosen so that both Z and m^* are increased further.

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

    SciTech Connect

    Gerber, G.B.; Hegela, M.; Vankerkom, J.; Kirchmann, R.; Maisin, J.R.; Lambiet-Collier, M. )

    1989-08-01

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

  15. (Giant) Proximity Effects in high-Tc superlattices

    NASA Astrophysics Data System (ADS)

    Bozovic, Ivan

    2006-03-01

    Molecular beam epitaxy enables one to synthesize HTS thin films with rms surface roughness in the range 0.2-0.5 nm, much less than the unit cell height (1-2 nm).^1 One can also make atomically smooth multilayers and superlattices in which HTS or spacer layers can be just one unit cell thick if so desired. A detailed study of transport properties of such heterostructures has already revealed some unexpected findings.^2 In junctions where the barrier is made out of underdoped cuprate with a reduced critical temperature Tc, we observe the Giant Proximity Effect: supercurrent runs through very thick barrier layers even at temperature well above Tc (contrary to what is expected from the standard theory).^ Atomic smoothness of films and multilayers, excellent device uniformity, and reversible modulation of barrier properties by oxygen intake provided solid evidence against experimental artifacts such as pinholes and micro-shorts. Hence, the effect is real and intrinsic, and it defies the conventional explanation. Interpretation and significance of our experimental results will be discussed in the context of theoretical concepts such as the pseudogap, midgap states, electronic inhomogeneity, preformed pairs, and possibly resonant pair tunneling. The work at BNL is done in collaboration with G. Logvenov, V. Butko, A. Gozar and A. Bollinger. ^1 I. Bozovic et al., Phys. Rev. Lett. 89, 107001 (2002); P. Abbamonte et al., Science 297, 581 (2002). ^2 I. Bozovic et al., Nature 421, 873 (2003); Phys. Rev. Lett. 93, 157002 (2004).

  16. Power Systems Development Facility Gasification Test Campaign TC16

    SciTech Connect

    Southern Company Services

    2004-08-24

    In support of technology development to utilize coal for efficient, affordable, and environmentally clean power generation, the Power Systems Development Facility (PSDF) located in Wilsonville, Alabama, routinely demonstrates gasification technologies using various types of coals. The PSDF is an engineering scale demonstration of key features of advanced coal-fired power systems, including a KBR (formerly Kellogg Brown & Root) Transport Gasifier, a hot gas particulate control device, advanced syngas cleanup systems, and high-pressure solids handling systems. This report discusses Test Campaign TC16 of the PSDF gasification process. TC16 began on July 14, 2004, lasting until August 24, 2004, for a total of 835 hours of gasification operation. The test campaign consisted of operation using Powder River Basin (PRB) subbituminous coal and high sodium lignite from the North Dakota Freedom mine. The highest gasifier operating temperature mostly varied from 1,760 to 1,850 F with PRB and 1,500 to 1,600 F with lignite. Typically, during PRB operations, the gasifier exit pressure was maintained between 215 and 225 psig using air as the gasification oxidant and between 145 and 190 psig while using oxygen as the oxidant. With lignite, the gasifier operated only in air-blown mode, and the gasifier outlet pressure ranged from 150 to 160 psig.

  17. 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.

  18. 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.

  19. An Overview of ER-2 Platform Science during TC4

    NASA Astrophysics Data System (ADS)

    Platnick, S.; Newman, P. A.

    2007-12-01

    The NASA high-altitude ER-2 aircraft flew 11 science flight out of San Jose, Costa Rica during July and August 2007 as part of the NASA-sponsored Tropical Composition, Clouds and Climate Coupling Experiment (TC4). The ER-2 flew a remote sensing payload consisting of passive optical and microwave imagers (MAS/MASTER, CoSSIR, AMPR), a high spectral resolution IR imager (S-HIS), active sensors (CPL lidar, CRS and EDOP radars), spectral solar (SSFR) and IR flux radiometers, a microwave temperature profiler (MTP), and a visible video camera (MVIS). This suite of sensors provided a high spatial resolution simulator for cloud, aerosol, sounding, and trace gas retrieval capabilities from the "A-Train" constellation, in particular, the Aqua, CloudSat, and CALIPSO satellites. In this talk we present an overview of the ER-2 TC4 science and validation objectives, and a summary of the campaign accomplishments. Science goals included observations of convective system development, anvil cirrus property evolution (i.e., microphysics, optical properties, narrow and broadband radiative fluxes), tropical Tropopause Transition Layer (TTL) and subvisual cirrus detection and characterization, marine boundary layer cloud properties, aerosol transport and optical properties, and trace gas and atmospheric state characteristics. Coordination with the DC-8 and/or WB-57 aircrafts allowed for validation of various retrievals from these observations. Morning flights (due to adverse local afternoon weather conditions) included coordination with the Terra spacecraft when feasible.

  20. High-Tc Layered Ferrielectric Crystals by Coherent Spinodal Decomposition.

    PubMed

    Susner, Michael A; Belianinov, Alex; Borisevich, Albina; He, Qian; Chyasnavichyus, Marius; Demir, Hakan; Sholl, David S; Ganesh, Panchapakesan; Abernathy, Douglas L; McGuire, Michael A; Maksymovych, Petro

    2015-12-22

    Research in the rapidly developing field of 2D electronic materials has thus far been focused on metallic and semiconducting materials. However, complementary dielectric materials such as nonlinear dielectrics are needed to enable realistic device architectures. Candidate materials require tunable dielectric properties and pathways for heterostructure assembly. Here we report on a family of cation-deficient transition metal thiophosphates whose unique chemistry makes them a viable prospect for these applications. In these materials, naturally occurring ferrielectric heterostructures composed of centrosymmetric In4/3P2S6 and ferrielectrically active CuInP2S6 are realized by controllable chemical phase separation in van der Waals bonded single crystals. CuInP2S6 by itself is a layered ferrielectric with a ferrielectric transition temperature (Tc) just over room temperature, which rapidly decreases with homogeneous doping. Surprisingly, in our composite materials, the ferrielectric Tc of the polar CuInP2S6 phase increases. This effect is enabled by unique spinodal decomposition that retains the overall van der Waals layered morphology of the crystal, but chemically separates CuInP2S6 and In4/3P2S6 within each layer. The average spatial periodicity of the distinct chemical phases can be finely controlled by altering the composition and/or synthesis conditions. One intriguing prospect for such layered spinodal alloys is large volume synthesis of 2D in-plane heterostructures with periodically alternating polar and nonpolar phases. PMID:26566107

  1. 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

  2. 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

  3. 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

  4. Radiation-dosimetry and chemical-toxicity considerations for /sup 99/Tc

    SciTech Connect

    Coffey, J.L.; Hayes, R.L.; Rafter, J.J.; Watson, E.E.; Carlton, J.E.

    1982-01-01

    Technetium-99 (T/sub 1/2/ = 2.13 x 10/sup 5/ y) is produced in the fission of /sup 235/U and /sup 239/Pu. Technitium-99 has been found to contaminate some areas of the uranium re-enrichment process. ICRP-30 Part 2 gives the Annual Limit on Intake (ALI) for /sup 99/Tc as 2 x 10/sup 8/ Bq (5.4 mCi) for class D inhaled material (IC80). The ICRP states clearly that ALIs are based on radiation risk only and that chemical toxicity is not considered (IC79). No data wer found on the chemical toxicity of /sup 99/Tc, possibly because there are no stable isotopes of technetium with which to study the toxicity, although, because of its long T/sub 1/2/, /sup 99/Tc can, for all practical purposes, be considered stable. The ALI values for /sup 99/Tc are based on data obtained using high specific activity /sup 99m/Tc (T/sub 1/2/ = 6 h) and /sup 95m/Tc (T/sub 1/2/ = 61 days). Since the specific activities of /sup 99/Tc and Na/sup 99/TcO/sub 4/ are quite low (17 mCi/g and 9 mCi/g, respectively) and /sup 99/Tc is available in abundant supply, we have attempted to assess the relative radiation and chemical hazards that are associated with this radionuclide. The approach in this study was (1) to study the effect of chemical dose on the whole body retention of /sup 99/Tc sodium pertechnetate in rats and to relate these effects to the radiation dose and the ALI and (2) to compare the chemical toxicity of /sup 99/Tc sodium pertechnetate with the ALI at different chemical dose levels.

  5. 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.

  6. Mesalamine Suppresses the Expression of TC22, a Novel Tropomyosin Isoform Associated with Colonic Neoplasia

    PubMed Central

    Das, Koushik K.; Bajpai, Manisha; Kong, Yingxin; Liu, Jianying; Geng, Xin; Das, Kiron M.

    2009-01-01

    Although a protective role for mesalamine against colon cancer in ulcerative colitis has been shown epidemiologically, its molecular mechanism is unknown. We cloned and sequenced a novel human tropomyosin (hTM) isoform, TC22, which is an alternatively spliced variant of normal epithelial hTM isoform 5 (hTM5), identical apart from 25 C-terminal amino acids. TC22 is expressed in 100% of colorectal carcinoma but is not expressed in normal colon epithelial cells. To explore a molecular mechanism of chemoprevention, we examined the effect of mesalamine on TC22 expression using LS180 colon cancer cells. Expression of hTM5 and TC22 was investigated at the protein and gene levels by fluorescence-activated cell sorting and real-time reverse transcription-polymerase chain reaction. Small interference RNA (siRNA) against the TC22 variant were transfected into LS180 colon cancer cells, reducing protein and transcript levels by 45 to 50%. Mesalamine or sulfasalazine (2 mM), but not sulfapyridine, significantly (p < 0.02-0.006) reduced the expression of the TC22 transcript and significantly (p < 0.05 to <0.0002) reduced the expression of TC22 protein in a dose-dependent and reversible manner. Rosiglitazone, a specific peroxisome proliferator-activated receptor-γ (PPARγ) agonist, similarly and significantly (p < 0.002) reduced TC22 protein expression. A polymerase chain reaction array of 84 cancer-related genes performed on TC22 siRNA-transfected cells demonstrated a significant (more than two times) change in targets involved in apoptosis, adhesion, angiogenesis, and tissue remodeling. We conclude that mesalamine, sulfasalazine, and rosiglitazone significantly reduced the cellular expression of TC22, implicating PPARγ in this modulation. Similar suppression of TC22 by siRNA produced gene level changes on several critical carcinogenic pathways. These findings suggest a novel antineoplastic molecular effect of mesalamine. PMID:19369484

  7. Development and Pharmacological Evaluation of New Bone-Targeted (99m)Tc-Radiolabeled Bisphosphonates.

    PubMed

    Makris, George; Tseligka, Eirini D; Pirmettis, Ioannis; Papadopoulos, Minas S; Vizirianakis, Ioannis S; Papagiannopoulou, Dionysia

    2016-07-01

    A novel bisphosphonate, 1-(3-aminopropylamino)ethane-1,1-diyldiphosphonic acid (3), was coupled to the tridentate chelators di-2-picolylamine, 2-picolylamine-N-acetic acid, iminodiacetic acid, 3-((2-aminoethyl)thio)-3-(1H-imidazol-4-yl)propanoic acid, and 2-((2-carboxyethyl)thio)-3-(1H-imidazol-4-yl)propanoic acid to form ligands 6, 9, 11, 15, and 19, respectively. Organometallic complexes of the general formula [Re/(99m)Tc(CO)3(κ(3)-L)] were synthesized, where L denotes ligand 6, 9, 11, 15, or 19. The rhenium complexes were prepared at the macroscopic level and characterized by spectroscopic methods. The technetium-99m organometallic complexes were synthesized in high yield and were identified by comparative reversed-phase HPLC with their Re analogues. The (99m)Tc tracers were stable in vitro and exhibited binding to hydroxyapatite. In biodistribution studies, all of the (99m)Tc complexes exhibited high bone uptake superior to that of 25, which is the directly (99m)Tc-labeled bisphosphonate 3, and comparable to that of (99m)Tc-methylene diphosphonate ((99m)Tc-MDP). The tracers [(99m)Tc(CO)3(6)] (26), [(99m)Tc(CO)3(9)] (27), [(99m)Tc(CO)3(11)] (28), and [(99m)Tc(CO)3(15)] (29) exhibited higher bone/blood ratios than (99m)Tc-MDP. 26 had the highest bone uptake at 1 h p.i. The new bisphosphonates showed no substantial growth inhibitory capacity in PC-3, Saos-2, and MCF-7 established cancer cell lines at low concentrations. Incubation of 26 with the same cancer cell lines indicated a rapid and saturated uptake. The promising properties of 26-29 indicate their potential for use as bone-imaging agents. PMID:27170456

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

    PubMed Central

    2013-01-01

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

  9. Design and performance of an automated radionuclide separator: its application on the determination of ⁹⁹Tc 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

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

    PubMed

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

    2011-03-01

    The isotope (99)Tc (β(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 (α(2)-P(2)W(17)O(61))(10-) and (α(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(α(1)/α(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(α(1)-P(2)W(17)O(61))(7-) species compared to the Tc(V)O(α(2)-P(2)W(17)O(61))(7-) analog. The α(1) defect is unique in that a basic oxygen atom is positioned toward the α(1) site, and the Tc(V)O center appears to form a dative metal-metal bond with a framework W site. These attributes may lead to the assistance of protonation events that facilitate reduction. Electrochemistry comparison shows that the Re(V) analogs are about 200 mV more difficult to reduce in accordance with periodic trends. PMID:21268605

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

    SciTech Connect

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

    2011-01-10

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

  12. Experimental study of 99mTc-aluminum oxide use for sentinel lymph nodes detection

    NASA Astrophysics Data System (ADS)

    Chernov, V. I.; Sinilkin, I. G.; Zelchan, R. V.; Medvedeva, A. A.; Lyapunov, A. Yu.; Bragina, O. D.; Varlamova, N. V.; Skuridin, V. S.

    2016-08-01

    The purpose of the study was a comparative research in the possibility of using the radiopharmaceuticals 99mTc-Al2O3 and 99mTc-Nanocis for visualizing sentinel lymph nodes. The measurement of the sizes of 99mTc-Al2O3 and 99mTc-Nanocis colloidal particles was performed in seven series of radiopharmaceuticals. The pharmacokinetics of 99mTc-Al2O3 and 99mTc-Nanocis was researched on 50 white male rats. The possibility of the use of 99mTc-Al2O3 and 99mTc-Nanocis for lymphoscintigraphy was studied in the experiments on 12 white male rats. The average dynamic diameter of the sol particle was 52-77 nm for 99mTc-Al2O3 and 16.7-24.5 nm for 99mTc-Nanocis. Radiopharmaceuticals accumulated in the inguinal lymph node in 1 hour after administration; the average uptake of 99mTc-Al2O3 was 8.6% in it, and the accumulation of 99mTc-Nanocis was significantly lower—1.8% (p < 0.05). In all study points the average uptake of 99mTc-Al2O3 in the lymph node was significantly higher than 99mTc-Nanocis accumulation. The results of dynamic scintigraphic studies in rats showed that 99mTc-Al2O3 and 99mTc-Nanocis actively accumulated into the lymphatic system. By using 99mTc-Al2O3 inguinal lymph node was determined in 5 minutes after injection and clearly visualized in all the animals in the 15th minute, when the accumulation became more than 1% of the administered dose. Further observation indicated that the 99mTc-Al2O3 accumulation reached a plateau in a lymph node (average 10.5%) during 2-hour study and then its accumulation remained practically at the same level, slightly increasing to 12% in 24 hours. In case of 99mTc-Nanocis inguinal lymph node was visualized in all animals for 15 min when it was accumulated on the average 1.03% of the administered dose. Plateau of 99mTc-Nanocis accumulation in the lymph node (average 2.05%) occurred after 2 hours of the study and remained almost on the same level (in average 2.3%) for 24 hours. Thus, the experimental study of a new domestic

  13. Magnetic and thermal properties of high Tc superconductors

    SciTech Connect

    Lee, Wonchoon.

    1990-09-21

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

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

    PubMed Central

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

    2015-01-01

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

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

    PubMed

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

    1991-07-01

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

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

    PubMed

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

    2015-01-01

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

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

    PubMed Central

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

    2015-01-01

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

  18. Assessment of the direct cyclotron production of (99m)Tc: An approach to crisis management of (99m)Tc shortage.

    PubMed

    Rovais, Mohammad Reza Aboudzadeh; Aardaneh, Khosro; Aslani, Gholamreza; Rahiminejad, Ali; Yousefi, Kamran; Boulouri, Fatemeh

    2016-06-01

    Nowadays, the cyclotron production of technetium-99m ((99m)Tc) has been increased, due to the worldwide (99m)Tc generator shortage. In the present work, an improved strategy for the production of (99m)Tc, using the proton irradiation of the enriched (100)Mo was developed. The performance of this method in terms of the production yield, chemical purity, radiochemical purity, as well as radionuclide purity was evaluated. The average production yield was measured to be 356MBqμA(-1)h(-1). A good agreement was found between the calculated production yield and the experimental one. The radiochemical separation and total recovery yields of (99m)Tc were 92% and 69%, respectively. The radiochemical and the radionuclide purities of the (99m)Tc were 99% and >99.99% at the end of purification, respectively. The results of quality control tests (QC) support the concept that cyclotron-produced (99m)Tc is suitable for preparation of USP-compliant. PMID:27015650

  19. Comparison of the Absorbed Dose for 99mTc-Diethylenetriaminepentaacetic Acid and 99mTc-Ethylenedicysteine Radiopharmaceuticals using Medical Internal Radiation Dosimetry

    PubMed Central

    Pirdamooie, Shokufeh; Shanei, Ahmad; Moslehi, Masoud

    2015-01-01

    The aim of this study was the investigation of absorbed dose to the kidneys, spleen, and liver during technetium-99 m ethylene dicysteine and technetium-99 m diethylenetriaminepentaacetic acid (99mTc-EC and 99mTc-DTPA) kidney scan. Patients who had been prepared for the kidney scan, were divided into two groups (Groups 1 and 2). The first group (Group 1) and the second group (Group 2) received intravenous injection of 99mTc-EC and 99mTc-DTP, respectively. A certain amount of radiopharmaceuticals was injected into each patient and was immediately imaged with dual-head gamma camera to calculate the activity through the conjugated view method. Then, the doses of kidney, liver, and spleen were measured using medical internal radiation dosimetry method. Finally, absorbed dose of these organs was compared. Based on these different results (P < 0.05), organs absorbed dose was significantly less with radiopharmaceutical 99mTc-EC as compared with 99mTc-DTPA. PMID:26284173

  20. 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

  1. Insect Tc-six4 marks a unit with similarity to vertebrate placodes.

    PubMed

    Posnien, Nico; Koniszewski, Nikolaus; Bucher, Gregor

    2011-02-01

    Cranial placodes are specialized ectodermal regions in the developing vertebrate head that give rise to both neural and non-neural cell types of the neuroendocrine system and the sense organs of the visual, olfactory and acoustic systems. The cranial placodes develop from a panplacodal region which is specifically marked by genes of the eyes absent/eya and two "six homeobox" family members (sine oculis/six1 and six4). It had been believed that cranial placodes are evolutionary novelties of vertebrates. However, data from non-vertebrate chordates suggest that placode-like structures evolved in the chordate ancestor already. Here, we identify a morphological structure in the embryonic head of the beetle Tribolium castaneum with placode-like features. It is marked by the orthologs of the panplacodal markers Tc-six4, Tc-eya and Tc-sine oculis/six1 (Tc-six1) and expresses several genes known to be involved in adenohypophyseal placode development in vertebrates. Moreover, it contributes to both epidermal and neural tissues. We identify Tc-six4 as a specific marker for this structure that we term the insect head placode. Finally, we reveal the regulatory gene network of the panplacodal genes Tc-six4, Tc-eya and Tc-six1 and identify them as head epidermis patterning genes. Our finding of a placode-like structure in an insect suggests that a placode precursor was already present in the last common ancestor of bilaterian animals. PMID:21034730

  2. The inducible costimulator augments Tc17 cell responses to self and tumor tissue.

    PubMed

    Nelson, Michelle H; Kundimi, Sreenath; Bowers, Jacob S; Rogers, Carolyn E; Huff, Logan W; Schwartz, Kristina M; Thyagarajan, Krishnamurthy; Little, Elizabeth C; Mehrotra, Shikhar; Cole, David J; Rubinstein, Mark P; Paulos, Chrystal M

    2015-02-15

    The inducible costimulator (ICOS) plays a key role in the development of Th17 cells, but its role in the development and antitumor activity of IL-17-producing CD8(+) T cells (Tc17) remains unknown. We found that ICOS costimulation was important for the functional maintenance, but not differentiation, of Tc17 cells in vitro. Blocking the ICOS pathway using an antagonist mAb or by using recipient mice genetically deficient in the ICOS ligand reduced the antitumor activity of adoptively transferred Tc17 cells. Conversely, activating Tc17 cells with an ICOS agonist in vitro enhanced their capacity to eradicate melanoma and induce autoimmune vitiligo when infused into mice. However, ICOS stimulation did not augment the antitumor activity of IL-2 expanded T cells. Additional investigation revealed that ICOS stimulation not only increased IL-2Rα, CXCR3, and IL-23R expression on Tc17 cells, but also dampened their expression of suppressive molecule CD39. Although Tc17 cells activated with an ICOS agonist cosecreted heightened IL-17A, IL-9, and IFN-γ, their therapeutic effectiveness was critically dependent on IFN-γ production. Depletion of IL-17A and IL-9 had little impact on antitumor Tc17 cells activated with an ICOS agonist. Collectively, our work reveals that the ICOS pathway potentiates the antitumor activity of adoptively transferred Tc17 cells. This work has major implications for the design of vaccine, Ab and cell-based therapies for autoimmunity, infectious disease, and cancer. PMID:25576595

  3. 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

    ... Energy Regulatory Commission TC Ravenswood, LLC v. New York Independent System Operator, Inc.; Notice of... 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...

  4. Imaging of Cerebral Amyloid Angiopathy with Bivalent (99m)Tc-Hydroxamamide Complexes.

    PubMed

    Iikuni, Shimpei; Ono, Masahiro; Watanabe, Hiroyuki; Matsumura, Kenji; Yoshimura, Masashi; Kimura, Hiroyuki; Ishibashi-Ueda, Hatsue; Okamoto, Yoko; Ihara, Masafumi; Saji, Hideo

    2016-01-01

    Cerebral amyloid angiopathy (CAA), characterized by the deposition of amyloid aggregates in the walls of cerebral vasculature, is a major factor in intracerebral hemorrhage and vascular cognitive impairment and is also associated closely with Alzheimer's disease (AD). We previously reported (99m)Tc-hydroxamamide ((99m)Tc-Ham) complexes with a bivalent amyloid ligand showing high binding affinity for β-amyloid peptide (Aβ(1-42)) aggregates present frequently in the form in AD. In this article, we applied them to CAA-specific imaging probes, and evaluated their utility for CAA-specific imaging. In vitro inhibition assay using Aβ(1-40) aggregates deposited mainly in CAA and a brain uptake study were performed for (99m)Tc-Ham complexes, and all (99m)Tc-Ham complexes with an amyloid ligand showed binding affinity for Aβ(1-40) aggregates and very low brain uptake. In vitro autoradiography of human CAA brain sections and ex vivo autoradiography of Tg2576 mice were carried out for bivalent (99m)Tc-Ham complexes ([(99m)Tc]SB2A and [(99m)Tc]BT2B), and they displayed excellent labeling of Aβ depositions in human CAA brain sections and high affinity and selectivity to CAA in transgenic mice. These results may offer new possibilities for the development of clinically useful CAA-specific imaging probes based on the (99m)Tc-Ham complex. PMID:27181612

  5. 99Tc(VII) Retardation, Reduction, and Redox Rate Scaling in Naturally Reduced Sediments

    SciTech Connect

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

    2015-10-15

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

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

    NASA Astrophysics Data System (ADS)

    Kanazawa, I.; Sasaki, T.

    2015-10-01

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

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

    SciTech Connect

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

    1982-03-01

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

  8. Imaging of Cerebral Amyloid Angiopathy with Bivalent 99mTc-Hydroxamamide Complexes

    PubMed Central

    Iikuni, Shimpei; Ono, Masahiro; Watanabe, Hiroyuki; Matsumura, Kenji; Yoshimura, Masashi; Kimura, Hiroyuki; Ishibashi-Ueda, Hatsue; Okamoto, Yoko; Ihara, Masafumi; Saji, Hideo

    2016-01-01

    Cerebral amyloid angiopathy (CAA), characterized by the deposition of amyloid aggregates in the walls of cerebral vasculature, is a major factor in intracerebral hemorrhage and vascular cognitive impairment and is also associated closely with Alzheimer’s disease (AD). We previously reported 99mTc-hydroxamamide (99mTc-Ham) complexes with a bivalent amyloid ligand showing high binding affinity for β-amyloid peptide (Aβ(1–42)) aggregates present frequently in the form in AD. In this article, we applied them to CAA-specific imaging probes, and evaluated their utility for CAA-specific imaging. In vitro inhibition assay using Aβ(1–40) aggregates deposited mainly in CAA and a brain uptake study were performed for 99mTc-Ham complexes, and all 99mTc-Ham complexes with an amyloid ligand showed binding affinity for Aβ(1–40) aggregates and very low brain uptake. In vitro autoradiography of human CAA brain sections and ex vivo autoradiography of Tg2576 mice were carried out for bivalent 99mTc-Ham complexes ([99mTc]SB2A and [99mTc]BT2B), and they displayed excellent labeling of Aβ depositions in human CAA brain sections and high affinity and selectivity to CAA in transgenic mice. These results may offer new possibilities for the development of clinically useful CAA-specific imaging probes based on the 99mTc-Ham complex. PMID:27181612

  9. Imaging of Cerebral Amyloid Angiopathy with Bivalent 99mTc-Hydroxamamide Complexes

    NASA Astrophysics Data System (ADS)

    Iikuni, Shimpei; Ono, Masahiro; Watanabe, Hiroyuki; Matsumura, Kenji; Yoshimura, Masashi; Kimura, Hiroyuki; Ishibashi-Ueda, Hatsue; Okamoto, Yoko; Ihara, Masafumi; Saji, Hideo

    2016-05-01

    Cerebral amyloid angiopathy (CAA), characterized by the deposition of amyloid aggregates in the walls of cerebral vasculature, is a major factor in intracerebral hemorrhage and vascular cognitive impairment and is also associated closely with Alzheimer’s disease (AD). We previously reported 99mTc-hydroxamamide (99mTc-Ham) complexes with a bivalent amyloid ligand showing high binding affinity for β-amyloid peptide (Aβ(1–42)) aggregates present frequently in the form in AD. In this article, we applied them to CAA-specific imaging probes, and evaluated their utility for CAA-specific imaging. In vitro inhibition assay using Aβ(1–40) aggregates deposited mainly in CAA and a brain uptake study were performed for 99mTc-Ham complexes, and all 99mTc-Ham complexes with an amyloid ligand showed binding affinity for Aβ(1–40) aggregates and very low brain uptake. In vitro autoradiography of human CAA brain sections and ex vivo autoradiography of Tg2576 mice were carried out for bivalent 99mTc-Ham complexes ([99mTc]SB2A and [99mTc]BT2B), and they displayed excellent labeling of Aβ depositions in human CAA brain sections and high affinity and selectivity to CAA in transgenic mice. These results may offer new possibilities for the development of clinically useful CAA-specific imaging probes based on the 99mTc-Ham complex.

  10. Underlying mechanisms of pseudogap phenomena and Bose-liquid superconductivity in high-Tc cuprates

    NASA Astrophysics Data System (ADS)

    Dzhumanov, S.; Karimboev, E. X.; Djumanov, Sh. S.

    2016-06-01

    We show that the high-Tc cuprates are non-BCS superconductors exhibiting distinct pseudogap (PG) behaviors (related to real and momentum space excitations) and other anomalies above Tc, novel Bose-liquid superconductivity below Tc, and also a λ-like superconducting (SC) transition at Tc similar to the λ transition in liquid 4He. In these materials, the relevant charge carriers are polarons which are bound into bosonic Cooper pairs above Tc followed by condensing into a Bose superfluid at Tc. We found that the polaronic effects and related PG weaken with increasing of the doping level and disappear in the overdoped region, where the crossover from Bose-liquid to Fermi-liquid (BCS-type) superconductivity occurs at the quantum critical point. We identify the real phase diagrams of the cuprates, the PG and vortex-like states above Tc, the novel SC state and two distinct SC phases below Tc like two superfluid phases of 3He, and explain the rich cuprate phenomenology from lightly doped to overdoped region.

  11. The inducible costimulator augments Tc17 cell responses to self and tumor tissue

    PubMed Central

    Nelson, Michelle H.; Kundimi, Sreenath; Bowers, Jacob S.; Rogers, Carolyn E.; Huff, Logan W.; Schwartz, Kristina M.; Thyagarajan, Krishnamurthy; Little, Elizabeth C.; Mehrotra, Shikhar; Cole, David J.; Rubinstein, Mark P.; Paulos, Chrystal M.

    2014-01-01

    The inducible costimulator (ICOS) plays a key role in CD4+ Th17 cell development, but its role in CD8+ Tc17 cell development and self/tumor immunity remains unknown. We found that ICOS co-stimulation was important for the functional maintenance but not differentiation of Tc17 cells in vitro. Blocking the ICOS pathway using an antagonist antibody or by using mice genetically deficient in the ICOS ligand (ICOSL) reduced the antitumor activity of adoptively transferred Tc17 cells. Conversely, activating Tc17 cells with an ICOS agonist in vitro enhanced their capacity to eradicate melanoma and induce autoimmune vitiligo when infused into mice. However, ICOS stimulation did not augment the antitumor activity of IL-2 expanded T cells. Additional investigation revealed that ICOS stimulation not only increased IL-2Rα, CXCR3 and IL-23R expression on Tc17 cells, but also dampened their expression of suppressive molecule CD39. Although Tc17 cells activated with an ICOS agonist co-secreted heightened IL-17A, IL-9 and IFN-γ, their therapeutic effectiveness was critically dependent on IFN-γ production. Depletion of IL-17A and IL-9 had little impact of antitumor Tc17 cells activated with an ICOS agonist. Collectively, our work reveals that the ICOS pathway potentiates the antitumor activity of adoptively transferred Tc17 cells. This work has major implications for the design of vaccine, antibody and cell-based therapies for autoimmunity, infectious disease and cancer. PMID:25576595

  12. Metallic alloy targets for high Tc superconducting film deposition

    NASA Astrophysics Data System (ADS)

    Manini, P.; Nigro, A.; Romano, P.; Vaglio, R.

    1989-02-01

    Many experiments are nowadays conducting worldwide on superconducting films based on the recently developed high Tc superconductor materials (YBCO, BISCO, etc). There are different ways to produce these films, among which sputtering and evaporation are most popular. Normally, use is made of oxides, pure metals or compounds as material sources. In the present paper we describe the fabrication process and the physico-chemical characteristics of various metallic alloy components for both sputtering and evaporation processes which show various advantages in terms of stability, easiness of use, purity, flexibility in composition and shape and allow good process control. Deposition techniques and experimental results obtained on thin films of the new superconductors realized starting from these alloys are also reported.

  13. Vent Flowing Cold Gas and T/C Rake

    NASA Technical Reports Server (NTRS)

    1963-01-01

    Vent flowing cryogenic fuel and T/C Rake mounted on a 1/10 scale model Centaur in the l0 x l0 Foot Supersonic Wind Tunnel. The fuel being used is liquid hydrogen. The point of the test is to determine how far to expel venting fuel from the rocket body to prevent explosion at the base of the vehicle. This vent is used as a safety valve for the fumes created when loading the fuel tanks during launch preparation. Liquid hydrogen has to be kept at a very low temperature. As it heats, it turns to gas and increases pressure in the tank. It therefore has to be vented overboard while the rocket sits on the pad. The test is being run at the Lewis Research Center, now known as John H. Glenn Research Center, Lewis Field.

  14. In-Situ Data for Microphysical Retrievals: TC4, 2007

    DOE Data Explorer

    Mace, Gerald

    2016-04-01

    This data set is derived from measurements collected in situ by the NASA DC8 during the Tropical Cloud Climate Composition Coupling Experiment (TC4) that was conducted during July and August, 2007 (Toon et al., 2010). During this experiment the DC8 was based in San Jose, Costa Rica and sampled clouds in the maritime region of the Eastern Pacific and adjoining continental areas. The primary objective of the DC8 during this deployment was to sample ice clouds associated with convective activity. While the vast majority of the data are from ice-phase clouds that have recent association with convection, other types of clouds such as boundary layer clouds and active convection were also sampled and are represented in this data set. The derived data set, as compiled in this delivery, includes approximately 15,000 5-second averaged measurements collected by the NASA DC8.

  15. On the correct electronic ground state of Tc( g )

    SciTech Connect

    Rard, J.A. ); Rand, M.H. ); Thornback, J.R. ); Wanner, H. )

    1991-05-01

    The electronic ground state of Tc({ital g}) is {sup 6}{ital S}{sub 5/2}, which arises from a 4{ital d}{sup 5}5{ital s}{sup 2} valence electron configuration. However, there are several treatises and review articles in which the ground state is incorrectly given as {ital S}{sub 9/2} with a valence electron configuration of 4{ital d}{sup 6}5{ital s}{sup 1}. The origin of this incorrect assignment was traced to the misinterpretation of a paper on the hyperfine splitting of the optical spectrum of technetium, and to confusion between nuclear and electronic spins.

  16. Global Phase Diagram of the High-Tc Cuprates

    NASA Astrophysics Data System (ADS)

    Chen, Han-Dong; Zhang, Shou-Cheng

    2006-02-01

    We propose a bosonic effective quantum Hamiltonian based on the projected SO(5) model with extended interactions, which can be derived from the microscopic models of the cuprates. The global phase diagram of this model is obtained using mean-field theory and the quantum Monte Carlo simulation. We show that this single quantum model can account for most salient features observed in the high-Tc cuprates, with different families of the cuprates attributed to different traces in the global phase diagram. A particular prediction of this theory is the checkerboard state of the d-wave hole pairs formed at certain magic filling fractions. We shall describe various properties of this state and present evidence that this novel state has been detected in recent STM and transport experiments.

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

    NASA Astrophysics Data System (ADS)

    Riofrio, Louise

    2015-08-01

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

  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. 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

  20. High Tc layered ferrielectric crystals by coherent spinodal decomposition

    DOE PAGESBeta

    Susner, Michael A.; Belianinov, Alex; Borisevich, Albina Y.; He, Qian; Chyasnavichyus, Marius; Demir, Hakan; Sholl, David; Ganesh, Panchapakesan; Abernathy, Douglas L.; McGuire, Michael A.; et al

    2015-11-13

    Research in the rapidly-developing field of 2D-electronic materials has thus far been focused on metallic and semiconducting materials. However, complementary dielectric materials such as non-linear dielectrics are needed to enable realistic device architectures. Candidate materials require tunable dielectric properties and pathways for heterostructure assembly. Here we report on a family of cation-deficient transition metal thiophosphates whose unique chemistry makes them a viable prospect for these applications. In these materials, naturally occurring ferrielectric heterostructures composed of centrosymmetric In4/3P2S6 and ferrielectrically-active CuInP2S6 are realized by controllable chemical phase separation in van-der-Waals bonded single crystals. CuInP2S6 by itself is a layered ferrielectric withmore » Tc just over room-temperature which rapidly decreases with homogenous doping. Surprisingly, in our composite materials, the ferrielectric Tc of the polar CuInP2S6 phase increases. This effect is enabled by unique spinodal decomposition that retains the overall van-der-Waals layered morphology of the crystal, but chemically separates CuInP2S6 and In4/3P2S6 within each layer. The average spatial periodicity of the distinct chemical phases can be finely controlled by altering the composition and/or synthesis conditions. One intriguing prospect for such layered spinodal alloys is large volume synthesis of 2D in-plane heterostructures with periodically alternating polar and non-polar phases.« less

  1. Towards a complete Fermi surface in underdoped high Tc superconductors

    NASA Astrophysics Data System (ADS)

    Harrison, Neil

    The discovery of magnetic quantum oscillations in underdoped high Tc superconductors raised many questions, and initiated a quest to understand the origin of the Fermi surface the like of which had not been seen since the very first discovery of quantum oscillations in elemental bismuth. While studies of the Fermi surface of materials are today mostly assisted by computer codes for calculating the electronic band structure, this was not the case in the underdoped high Tc materials. The Fermi surface was shown to reconstructed into small pockets, yet there was no hint of a viable order parameter. Crucial clues to understanding the origin of the Fermi surface were provided by the small value of the observed Fermi surface cross-section, the negative Hall coefficient and the small electronic heat capacity at high magnetic fields. We also know that the magnetic fields were likely to be too weak to destroy the pseudogap and that vortex pinning effects could be seen to persist to high magnetic fields at low temperatures. I will show that the Fermi surface that appears to fit best with the experimental observations is a small electron pocket formed by connecting the nodal `Fermi arcs' seen in photoemission experiments, corresponding to a density-wave state with two different orthogonal ordering vectors. The existence of such order has subsequently been detected by x-ray scattering experiments, thereby strengthening the case for charge ordering being responsible for reconstructing the Fermi surface. I will discuss new efforts to understand the relationship between the charge ordering and the pseudogap state, discussing the fate of the quasiparticles in the antinodal region and the dimensionality of the Fermi surface. The author acknowledges contributions from Suchitra Sebastian, Brad Ramshaw, Mun Chan, Yu-Te Hsu, Mate Hartstein, Gil Lonzarich, Beng Tan, Arkady Shekhter, Fedor Balakirev, Ross McDonald, Jon Betts, Moaz Altarawneh, Zengwei Zhu, Chuck Mielke, James Day, Doug

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

    NASA Astrophysics Data System (ADS)

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

    2010-06-01

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

  3. High Tc layered ferrielectric crystals by coherent spinodal decomposition

    SciTech Connect

    Susner, Michael A; Belianinov, Alex; Borisevich, Albina Y; He, Qian; Sholl, David; Ganesh, Panchapakesan; Abernathy, Douglas L; McGuire, Michael A; Maksymovych, Petro

    2015-01-01

    Research in the rapidly-developing field of 2D-electronic materials has thus far been focused on metallic and semiconducting materials. However, complementary dielectric materials such as non-linear dielectrics are needed to enable realistic device architectures. Candidate materials require tunable dielectric properties and pathways for heterostructure assembly. Here we report on a family of cation-deficient transition metal thiophosphates whose unique chemistry makes them a viable prospect for these applications. In these materials, naturally occurring ferrielectric heterostructures composed of centrosymmetric In4/3P2S6 and ferrielectrically-active CuInP2S6 are realized by controllable chemical phase separation in van-der-Waals bonded single crystals. CuInP2S6 by itself is a layered ferrielectric with Tc just over room-temperature which rapidly decreases with homogenous doping. Surprisingly, in our composite materials, the ferrielectric Tc of the polar CuInP2S6 phase increases. This effect is enabled by unique spinodal decomposition that retains the overall van-der-Waals layered morphology of the crystal, but chemically separates CuInP2S6 and In4/3P2S6 within each layer. The average spatial periodicity of the distinct chemical phases can be finely controlled by altering the composition and/or synthesis conditions. One intriguing prospect for such layered spinodal alloys is large volume synthesis of 2D in-plane heterostructures with periodically alternating polar and non-polar phases.

  4. 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.

  5. The recovery of asteroid 2008 TC[subscript 3

    SciTech Connect

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

    2011-09-06

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

  6. 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

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

    SciTech Connect

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

    1989-08-01

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

  8. Clearance of Tc-99m DTPA in hemodialysis and peritoneal dialysis: concise communication

    SciTech Connect

    Wainer, E.; Boner, G.; Lubin, E.; Rosenfeld, J.B.

    1981-09-01

    The clearance of Tc-99m DTPA was studied in 14 patients undergoing hemodialysis (HD) or peritoneal dialysis (PD). Mean Tc-99m DTPA clearance during HD was 37.8% +/- 10.1 of creatinine clearance. Mean Tc-99m DTPA clearance in PD was 65.1% +/- 10.3 of creatinine clearance. Tc-99m DTPA, with a larger molecular weight than that of creatinine, is cleared relatively better during PD than during HD. Thus Tc-99m DTPA may be used in the assessment of the effectiveness of different dialytic treatments for substances of similar molecular weight. In addition, our study shows that clearance of DTPA both in HD and PD is sufficiently high to allow the removal of this chelating agent in patients with renal failure.

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

    PubMed Central

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

    2015-01-01

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

  10. Synthesis, characterization, and biological evaluation of new biotinylated (99m) Tc/Re-tricarbonyl complexes.

    PubMed

    Makris, George; Papagiannopoulou, Dionysia

    2016-03-01

    The synthesis and biological evaluation of three new biotinylated fac-[(99m)Tc/Re(CO)3](+) complexes with the tridentate ligands L1, L2, and L3 are reported. L1-L3 contain the chelators 2-((5-aminopentyl)(pyridin-2-ylmethyl)amino)acetic acid, 2-(2-aminoethylthio)-3-(1H-imidazol-4-yl)propanoic acid, and 2-amino-3-(1-carboxy-2-(1H-imidazol-4-yl)ethylthio)propanoic acid, respectively, which are conjugated to biotin's carboxylate via their amine group. The fac-[Re(CO)3(L1-L3)] complexes were synthesized and characterized by NMR and IR, where the (N,N,O) coordination for ReL1 and the (N,S,O) coordination for ReL2 and ReL3 were confirmed. The tracer complexes fac-[(99m)Tc(CO)3(L1-L3)] were synthesized in high yield and were found highly stable in 10(-3) M L-histidine and L-cysteine over 24 h. Furthermore, they exhibited high binding affinity (>90%) for avidin. Rat plasma studies showed complete cleavage of biotin from (99m)TcL1 after 1 h and a low percentage of intact (99m)TcL2 and (99m)TcL3 with no biotin cleavage metabolites present, over 24 h. Similarly, rat urine analysis showed the presence of intact (99m)TcL2 and (99m)TcL3, while (99m)TcL1 was cleaved. Biodistribution studies of (99m)TcL2 and (99m)TcL3 revealed fast blood and tissue clearance. PMID:26817576

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

    PubMed

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

    2015-01-01

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

  12. 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.

  13. [Clinical application of 99mTc-DTPA-galactosyl serum albumin in hepatobiliary disease].

    PubMed

    Ohno, K; Itoh, K; Nagao, K; Katoh, H; Okushiba, T; Satoh, M; Tomiyama, M; Hiraguchi, E; Tanabe, T

    1993-02-01

    A clinical study with 99mTc-DTPA-galactosyl serum albumin (99mTc-GSA) was performed in 10 patients with hepatobiliary disease. In this study, scintigraphic data and images with 99mTc-GSA were compared with several serological liver function tests, the hepatic blood perfusion index and image quality using 99mTc-DTPA-human serum albumin (99mTc-HSA). Dynamic and serial hepatic images were obtained over a 20 min period after 99mTc-GSA injection, and time activity curves from the heart and liver were generated. The blood clearance index (HH15), and the hepatic uptake index (LHL15) were calculated from each curve of the heart and liver, respectively. In addition, using two compartment fitting, the blood clearance (KH1, KH2) index was calculated, and using exponential fitting, the hepatic uptake index (KL) was calculated. The mean HH15 in LC group and non-LC group was 0.81 +/- 0.05, 0.64 +/- 0.10, respectively. The mean LHL15 in LC group and non-LC group was 0.79 +/- 0.04, 0.91 +/- 0.06, respectively. There were significant differences between non-LC group and LC group in HH15, and LHL15, KH1 and KL. There were also significant correlations of KH1 with HH15, and KL with LHL15. Parameters of 99mTc-GSA showed significant correlations with various liver functions. 99mTc-GSA scintigraphy showed clearer liver images in hepatobiliary diseases than 99mTc-HSA. These results suggest that 99mTc-GSA scintigraphy is useful in estimating preserved liver function and hepatic morphology. PMID:8468807

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

    NASA Astrophysics Data System (ADS)

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

    2015-07-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2014-12-01

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

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

    PubMed

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

    2014-10-21

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

  17. Correlation between Tc and Tms in EuBa 2(Cu 1-yZn y) 3O x superconductors under pressure

    NASA Astrophysics Data System (ADS)

    Phillips, J. C.

    1988-02-01

    The metal-semiconductor transition temperature Tmsdecreases as Tc increases in these materials. Maximum Tc is achieved for y ≥ 0.01 with Tc = Tms. A microscopic model for this behavior is presented and analyzed.

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

    SciTech Connect

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

    1990-01-01

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

  19. 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, T5αH, 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

  20. Consequences of POR mutations and polymorphisms.

    PubMed

    Miller, Walter L; Agrawal, Vishal; Sandee, Duanpen; Tee, Meng Kian; Huang, Ningwu; Choi, Ji Ha; Morrissey, Kari; Giacomini, Kathleen M

    2011-04-10

    P450 oxidoreductase (POR) transports electrons from NADPH to all microsomal cytochrome P450 enzymes, including steroidogenic P450c17, P450c21 and P450aro. Severe POR mutations A287P (in Europeans) and R457H (in Japanese) cause the Antley-Bixler skeletal malformation syndrome (ABS) plus impaired steroidogenesis (causing genital anomalies), but the basis of ABS is unclear. We have characterized the activities of ∼40 POR variants, showing that assays based on P450c17 activities, but not cytochrome c assays, correlate with the clinical phenotype. The human POR gene is highly polymorphic: the A503V sequence variant, which decreases P450c17 activities to ∼60%, is found on ∼28% of human alleles. A promoter polymorphism (∼8% of Asians and ∼13% of Caucasians) at -152 reduces transcriptional activity by half. Screening of 35 POR variants showed that most mutants lacking activity with P450c17 or cytochrome c also lacked activity to support CYP1A2 and CYP2C19 metabolism of EOMCC (a fluorogenic non-drug substrate), although there were some remarkable differences: Q153R causes ABS and has ∼30% of wild-type activity with P450c17 but had 144% of WT activity with CYP1A2 and 284% with CYP2C19. The effects of POR variants on CYP3A4, which metabolizes nearly 50% of clinically used drugs, was examined with multiple, clinically relevant drug substrates, showing that A287P and R457H dramatically reduce drug metabolism, and that A503V variably impairs drug metabolism. The degree of activity can vary with the drug substrate assayed, as the drugs can influence the conformation of the P450. POR is probably an important contributor to genetic variation in both steroidogenesis and drug metabolism. PMID:21070833

  1. Consequences of POR mutations and polymorphisms

    PubMed Central

    Miller, Walter L.; Agrawal, Vishal; Sandee, Duanpen; Tee, Meng Kian; Huang, Ningwu; Choi, Ji Ha; Morrissey, Kari; Giacomini, Kathleen M.

    2015-01-01

    P450 oxidoreductase (POR) transports electrons from NADPH to all microsomal cytochrome P450 enzymes, including steroidogenic P450c17, P450c21 and P450aro. Severe POR mutations A287P (in Europeans) and R457H (in Japanese) cause the Antley-Bixler skeletal malformation syndrome (ABS) plus impaired steroidogenesis (causing genital anomalies), but the basis of ABS is unclear. We have characterized the activities of ~40 POR variants, showing that assays based on P450c17 activities, but not cytochrome c assays, correlate with the clinical phenotype. The human POR gene is highly polymorphic: the A503V sequence variant, which decreases P450c17 activities to ~60%, is found on ~28% of human alleles. A promoter polymorphism (~8% of Asians and ~13% of Caucasians) at −152 reduces transcriptional activity by half. Screening of 35 POR variants showed that most mutants lacking activity with P450c17 or cytochrome c also lacked activity to support CYP1A2 and CYP2C19 metabolism of EOMCC (a fluorogenic non-drug substrate), although there were some remarkable differences: Q153R causes ABS and has ~30% of wild-type activity with P450c17 but had 144% of WT activity with CYP1A2 and 284% with CYP2C19. The effects of POR variants on CYP3A4, which metabolizes nearly 50% of clinically used drugs, was examined with multiple, clinically-relevant drug substrates, showing that A287P and R457H dramatically reduce drug metabolism, and that A503V variably impairs drug metabolism. The degree of activity can vary with the drug substrate assayed, as the drugs can influence the conformation of the P450. POR is probably an important contributor to genetic variation in both steroidogenesis and drug metabolism. PMID:21070833

  2. Radionuclide imaging in myocardial sarcoidosis. Demonstration of myocardial uptake of /sup 99m/Tc pyrophosphate and gallium

    SciTech Connect

    Forman, M.B.; Sandler, M.P.; Sacks, G.A.; Kronenberg, M.W.; Powers, T.A.

    1983-03-01

    A patient had severe congestive cardiomyopathy secondary to myocardial sarcoidosis. The clinical diagnosis was confirmed by radionuclide ventriculography, /sup 201/Tl, /sup 67/Ga, and /sup 99m/Tc pyrophosphate (TcPYP) scintigraphy. Myocardial TcPYP uptake has not been reported previously in sarcoidosis. In this patient, TcPYP was as useful as gallium scanning and thallium imaging in documenting the myocardial process.

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

    SciTech Connect

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

    1984-12-18

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

  4. 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. )

    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.

  5. 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 μm-sized, Fe-containing micas presumptively identified as celadonite. The markedly slower oxidation rates in FRC as compared to RG were attributed to mass

  6. Increased Number of Tc17 and Correlation with Th17 Cells in Patients with Immune Thrombocytopenia

    PubMed Central

    Hu, Yu; Ma, Dao-xin; Shan, Ning-ning; Zhu, Yuan-yuan; Liu, Xin-guang; Zhang, Lei; Yu, Shuang; Ji, Chun-yan; Hou, Ming

    2011-01-01

    Background IL-17-secreting CD8+ T cells (Tc17 subset) have recently been defined as a subpopulation of effector T cells implicated in the pathogenesis of autoimmune diseases. The role of Tc17 and correlation with Th17 cells in the pathophysiology of immune thrombocytopenia (ITP) remain unsettled. Design and Methods We studied 47 ITP patients (20 newly-diagnosed and 27 with complete response) and 34 healthy controls. IL-17-producing CD3+CD8+ cells (Tc17) and IL-17-producing CD3+CD8− cells (Th17) were evaluated by flow cytometry and expressed as a percentage of the total number of CD3+ cells. Specific anti-platelet glycoprotein (GP) GPIIb/IIIa and/or GPIb/IX autoantibodies were measured by modified monoclonal antibody specific immobilization of platelet antigens. Peripheral blood mononuclear cells of ITP patients were isolated, incubated in the presence of 0, 0.25, 0.5, or 1 µmol/L of dexamethasone for 72 h, and collected to detect Tc17 and Th17 cells by flow cytometric analysis. Results IL-17 was expressed on CD3+CD8− and CD3+CD8+ T cells. The percentages of Tc17 and Th17 cells in newly-diagnosed patients were significantly elevated compared to controls, and Tc17 was decreased after clinical treatment. The Th17∶Tc17 ratio was significantly lower in newly-diagnosed patients compared with controls, and was increased in patients who had complete response. There was a significantly positive correlation between Tc17 and Th17 cells in the control group, but not in the ITP patients. A positive correlation existed between Tc17 and the CD8∶CD4 ratio, as well as CD8+ cells in patients with ITP. The frequencies of Tc17 were marginally higher in autoantibody-negative patients than autoantibody-positive patients. Moreover, both Tc17 and Th17 cell percentages decreased as the concentration of dexamethasone in the culture media increased in ITP patients. Conclusions Tc17 and the Th17 subset are involved in the immunopathology of ITP. Blocking the abnormally increased

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

    SciTech Connect

    Fredrickson, J. K.; Zachara, J. M.; Plymale, A. E.; Heald, S. M.; McKinley, J. P.; Kennedy, D. W.; Liu, C.; Nachimuthu, P.

    2009-04-01

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

  8. 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

  9. Hypoxia-induced redox alterations and their correlation with 99mTc-MIBI and 99mTc-HL-91 uptake in colon cancer cells.

    PubMed

    Abrantes, Ana Margarida; Serra, Maria Elisa Silva; Gonçalves, Ana Cristina; Rio, Joana; Oliveiros, Bárbara; Laranjo, Mafalda; Rocha-Gonsalves, António Manuel; Sarmento-Ribeiro, Ana Bela; Botelho, Maria Filomena

    2010-02-01

    Colorectal cancer is one of the most common malignancies in the Western world and is an example of a solid tumour in which hypoxia is a common feature and develops because of the inability of the vascular system to supply adequate amounts of oxygen to growing tumours. Hypoxia effects on tumour cell biology can be detected and characterized using different methods. The use of imaging with gamma-emitting radionuclides to detect hypoxic tissue was first suggested by Chapman in 1979 [N Engl J Med 301 (1979) 1429-1432]. (99m)Tc-4,9-diaza-3,3,10,10-tetramethyldodecan-2,11-dione dioxime, also known as (99m)Tc-HL-91, has been among the most studied hypoxia markers. The objective of this study was to correlate the uptake of (99m)Tc-HL-91 and (99m)Tc-MIBI in colon cancer cells under normoxic and hypoxic conditions and to compare this information with some parameters such as oxidative stress and mitochondrial dysfunction of the cells analyzed by flow cytometry. Our results show that the in vitro (99m)Tc-HL-91 uptake is higher in hypoxic conditions, which is confirmed by the decreased uptake of (99m)Tc-MIBI. Flow cytometry results demonstrate that hypoxic conditions used are not enough to induce cellular death, but are responsible for the alterations in the intracellular redox environment, namely, increase of ROS production, proteic pimonidazol-derived adduct formation and alteration in the mitochondrial membrane permeability. Therefore, these results confirm that (99m)Tc-HL-91 is a radiopharmaceutical with favourable characteristics for detecting hypoxia. PMID:20152711

  10. 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.

  11. Theory of high-TC superconductivity: transition temperature

    NASA Astrophysics Data System (ADS)

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

    2010-12-01

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

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

    PubMed

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

    2016-01-01

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

  13. 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.

  14. Effect of van Hove singularities on high-Tc superconductivity in H3 S

    NASA Astrophysics Data System (ADS)

    Sano, Wataru; Koretsune, Takashi; Tadano, Terumasa; Akashi, Ryosuke; Arita, Ryotaro

    One of interesting open questions for the high-Tc superconductivity in sulfur hydrides is why some of the H3S phases under high pressures are so special. Recently, it has been pointed out that the presence of the van Hove singularities (vHs) around the Fermi level is crucial. Interestingly, such vHs are always absent in H2S, for which Tc is estimated to be much lower. Although there have been quantitative calculations of Tc based on the Migdal-Eliashberg theory, the effect of the vHs on the superconductivity is yet to be fully understood. This is because the energy dependence of the density of states (DOS) has been neglected to simplify the Eliashberg equation. In this study, we perform a calculation beyond the constant DOS approximation. In contrast with the conventional calculations, this approach with a sufficiently large number of Matsubara frequencies enables us to calculate Tc self-consistently without introducing the empirical pseudo Coulomb potential. We show that the constant DOS approximation seriously overestimates (underestimates) Tc by ~60 K (~10 K) for H3S (H2S). We then consider the effect of the anharmonicity of the phonon and the energy shift due to the zero-point motion. Eventually, Tc is estimated to be 180 K for H3S and 35 K for H2S, which successfully explains the pressure dependence of Tc observed in the experiment.

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

    PubMed Central

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

    2016-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2007-12-01

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

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

    SciTech Connect

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

    2013-01-01

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

  18. Is Brown Adipose Tissue Visualization Reliable on 99mTc-Methoxyisobutylisonitrile Diagnostic SPECT Scintigraphy?

    PubMed Central

    Haghighatafshar, Mahdi; Farhoudi, Farinaz

    2016-01-01

    Abstract The 99mTc-MIBI has been used with great value as a diagnostic technique in patients with primary hyperparathyroidism. False-positive scans may occur due to misinterpretation of the physiologic distribution of the 99mTc-MIBI. Reviewing consecutive SPECT scans, we evaluated this possibility and assessed how frequently brown adipose tissue (BAT) is seen on 99mTc-MIBI scintigraphy. Here, we retrospectively reviewed scans of consecutive patients who were evaluated for parathyroid adenomas from March 2015 to June 2015, using dual-phase (early and delayed) planar imaging and SPECT. We identified 60 patients (48 female and 12 male; mean age, 52.25 ± 15.20 years; range, 22–86 years). We detected the presence of 99mTc-MIBI uptake in BAT in 20 of 60 patients (33.33%) in the neck. Although the patients with 99mTc-MIBI uptake in BAT were younger (mean age, 48.85 ± 15.27 years, range, 26–73 years) than the patients with no 99mTc-MIBI uptake (mean age, 53.95 ± 15.07 years, range, 22–86 years), this difference was not statistically significant (P = 0.224). The percentage of female patients with BAT detection was higher (17/48 patients; 37.5%) than that of the male population (3/12 patients; 25%), this difference was not also statistically significant (P = 0.85). In patient population referred to 99mTc MIBI scintigraphy of the parathyroid glands, uptake of 99mTc-MIBI in BAT should not be misinterpreted with 99mTc-MIBI-avid-tumors. Fused SPECT/CT images (not SPECT-only) are necessary to distinguish BAT from bone, muscle, thyroid, myocardium, parathyroids, and other structures in the neck and chest. PMID:26765463

  19. 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,γ) 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

  20. High-Tc Nodeless s±-wave Superconductivity in (Y,La)FeAsO1-y with Tc=50K:As75-NMR Study

    NASA Astrophysics Data System (ADS)

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

    2012-10-01

    We report on an As75-NMR study on the Fe-pnictide high-Tc superconductor Y0.95La0.05FeAsO1-y (Y0.95La0.051111) with Tc=50K that includes no magnetic rare-earth elements. The measurement of the nuclear-spin lattice-relaxation rate (751/T1) has revealed that the nodeless bulk superconductivity takes place at Tc=50K while antiferromagnetic spin fluctuations develop moderately in the normal state. These features are consistently described by the multiple fully gapped s±-wave model based on the Fermi-surface nesting. Incorporating the theory based on band calculations, we propose that the reason that Tc=50K in Y0.95La0.051111 is larger than Tc=28K in La1111 is that the Fermi-surface multiplicity is maximized, and hence the Fermi-surface nesting condition is better than that in La1111.

  1. [Hepatic clearance of 99mTc-GSA in cases of postoperative biliary atresia--a retrospective comparison with hepatic clearance of 99mTc-PMT].

    PubMed

    Yamazaki, T; Maruoka, S; Yamada, S

    1998-11-01

    There are a few reports about usefulness of 99mTc-GSA liver scintigraphy (GSA imaging) for the evaluation of postoperative state of biliary atresia. However, comparison of significance for the disease between GSA imaging and 99mTc-PMT hepatobiliary imaging have not been reported. Fifty-six GSA imagings for 41 postoperative biliary atresia patients were reviewed and their scintigraphic findings and the functional parameters were compared with those obtained from 99mTc-PMT hepatobiliary imaging. In quantitative analysis, although the hepatic clearance of both tracers calculated by graphical analysis (Patlak plot) were well correlated in most cases, a discrepancy was observed in several cases with jaundice. The authors conclude that the hepatic clearance of 99mTc-GSA is a more accurate index of the hepatic reserve than that of 99mTc-PMT which can be influenced by hyperbilirubinemia and that the combination of both examinations is helpful to evaluate development of liver injury in postoperative biliary atresia patients. PMID:9916401

  2. Predicting Single-Layer Technetium Dichalcogenides (TcX₂, X = S, Se) with Promising Applications in Photovoltaics and Photocatalysis.

    PubMed

    Jiao, Yalong; Zhou, Liujiang; Ma, Fengxian; Gao, Guoping; Kou, Liangzhi; Bell, John; Sanvito, Stefano; Du, Aijun

    2016-03-01

    One of the least known compounds among transition metal dichalcogenides (TMDCs) is the layered triclinic technetium dichalcogenides (TcX2, X = S, Se). In this work, we systematically study the structural, mechanical, electronic, and optical properties of TcS2 and TcSe2 monolayers based on density functional theory (DFT). We find that TcS2 and TcSe2 can be easily exfoliated in a monolayer form because their formation and cleavage energy are analogous to those of other experimentally realized TMDCs monolayer. By using a hybrid DFT functional, the TcS2 and TcSe2 monolayers are calculated to be indirect semiconductors with band gaps of 1.91 and 1.69 eV, respectively. However, bilayer TcS2 exhibits direct-bandgap character, and both TcS2 and TcSe2 monolayers can be tuned from semiconductor to metal under effective tensile/compressive strains. Calculations of visible light absorption indicate that 2D TcS2 and TcSe2 generally possess better capability of harvesting sunlight compared to single-layer MoS2 and ReSe2, implying their potential as excellent light-absorbers. Most interestingly, we have discovered that the TcSe2 monolayer is an excellent photocatalyst for splitting water into hydrogen due to the perfect fit of band edge positions with respect to the water reduction and oxidation potentials. Our predictions expand the two-dimensional (2D) family of TMDCs, and the remarkable electronic/optical properties of monolayer TcS2 and TcSe2 will place them among the most promising 2D TMDCs for renewable energy application in the future. PMID:26859697

  3. μSR Studies on Magnetism in High-Tc Cuprates

    NASA Astrophysics Data System (ADS)

    Koike, Yoji; Adachi, Tadashi

    2016-09-01

    Since the discovery of high-Tc superconductivity in cuprates, muon spin relaxation (μSR) measurements have greatly contributed to the understanding of high-Tc superconductivity. In this paper, μSR studies on the magnetism in high-Tc cuprates obtained these past three decades are reviewed. Antiferromagnetic long-range order, 1/8 anomaly, stripes of Cu spins and holes, impurity-induced magnetism, magnetic-field-induced magnetism, pseudogap, ferromagnetism in the heavily overdoped regime, and undoped superconductivity in T'-type cuprates are discussed. Moreover, the fundamentals of μSR measurements for the study of magnetism are described for μSR beginners.

  4. Tight relation between the oxygen deficiency and Tc in LaFeAsO1-δ

    NASA Astrophysics Data System (ADS)

    Guo, Y. F.; Shi, Y. G.; Yu, S.; Belik, A. A.; Matsushita, Y.; Tanaka, M.; Katsuya, Y.; Kobayashi, K.; Hata, Y.; Yasuoka, H.; Yamaura, K.; Takayama-Muromachi, E.

    2010-12-01

    Oxygen vacant superconductors LaFeAsO1-δ were synthesized under a high-pressure condition. A bell-shaped feature in Tc vs. δ was observed for LaFeAsO1-δ as well as TbFeAsO1-δ. The optimized Tc was achieved at δ of 0.15, being comparable with that for TbFeAsO1-δ. The relatively wide δ window of LaFeAsO1-δ may merit scientific and technical studies of high-Tc superconductivity.

  5. Assessment of Using 99Mo and 99mTc Isotopes in Kuwait Medical Sector.

    PubMed

    Ali, Naser

    2016-04-01

    The Ministry of Health (MOH) in the state of Kuwait currently depends on importing the radioisotope molybdenum (Mo) in its isotopic form (Mo) to fulfill its demands. The present study was conducted on all nuclear medicine departments in the state of Kuwait. Daily, weekly, and monthly data were analyzed to statistically determine the current and future demands for the isotope Tc. This analysis was performed by collecting and analyzing data on MOH consumption of Tc for different diagnostic applications. The overall results indicate a partial decrease of 1.012% in the overall total demand for Tc up to the year 2018 for the state of Kuwait. PMID:26910031

  6. Popliteal cysts and deep venous thrombosis: Tc-99m red blood cell venography

    SciTech Connect

    Littlejohn, G.O.; Brand, C.A.; Ada, A.; Wong, C.

    1985-04-01

    Thirty-four patients who clinically were suspected of having deep venous thrombosis (DVT) underwent Tc-99m red blood cell (RBC) venography followed by contrast venography. The sensitivity (88%) and specificity (94%) of Tc-99m RBC venography of DVT confirmed findings of previous studies. Twenty-four patients who had proved popliteal cysts and swollen calves also were examined using Tc-99m RBC venography. Large cysts showed lack of DVT features, photon deficient cold areas in the popliteal fossa, and diversion of venous flow around the photon deficient area. These features were seen in 25% of the study population (six patients), and assisted in the distinction between the two conditions.

  7. The role of Tc-99m RBC scintigraphy in the differential diagnosis of orbital cavernous hemangioma.

    PubMed

    Sayit, E; Durak, I; Capakaya, G; Yilmaz, M; Durak, H

    2001-04-01

    The cavernous hemangioma is the most common benign orbital tumor in adults. Its presentation is during the forth to fifth decades with a slowly progressive unilateral proptosis. Intraconal cavernous hemangiomas may be difficult to differentiate from other intraconal lesions such as schwannomas, meningiomas and hemangiopericytomas. We report a case of orbital cavernous hemangioma diagnosed by Tc-99m RBC scintigraphy. Tc-99m RBC scintigraphy revealed a typical scintigraphic pattern in which there is intense focally increased uptake on the delayed image. We conclude that Tc-99m RBC scintigraphy can be a useful method in the differential diagnosis of orbital cavernous hemangioma as in hepatic hemangioma. PMID:11448074

  8. Low-Tc superconducting tunnel junction submillimeter wave receiver

    NASA Astrophysics Data System (ADS)

    Claude, Stephane M.; Ellison, Brian N.; Jones, A.; Matheson, D. N.; Little, L. T.; Davies, Steven R.

    1994-07-01

    A low Tc Pb alloy Superconductor-Insulator-Superconductor (SIS) tunnel junction heterodyne receiver has been constructed for astronomical use and tested over the frequency range of 400 to 540 GHz. Various alloy structures have been investigated in order to allow the production of small area SIS junctions with stable electrical characteristics and resistance to stress on cooling from 300 K to 4.2 K. Improvements in photolithography and thin film deposition techniques have been made that allow the fabrication of reliable sub-micron area junctions using suspended photoresist stencil and E-beam evaporation techniques. A single sub-micron area junction is mounted in a reduced height two tuner waveguide structure, which provides an optimum impedance match between the junction and the received signal. Performance measurements made with the receiver installed on the James Clerk Maxwell Telescope, Hawaii, show a total system double sideband noise equivalent temperature of 160 K at 460 GHz and 220 K at 490 GHz, measured in a 1 GHz instantaneous IF bandwidth centered at 4 GHz. The receiver demonstrates that Pb alloy tunnel junctions provide excellent sensitivity at submillimetre wavelengths and are sufficiently stable and reliable to allow use at a remote observing site.

  9. 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

  10. Terahertz imaging system using high-Tc superconducting oscillation devices

    NASA Astrophysics Data System (ADS)

    Tsujimoto, M.; Minami, H.; Delfanazari, K.; Sawamura, M.; Nakayama, R.; Kitamura, T.; Yamamoto, T.; Kashiwagi, T.; Hattori, T.; Kadowaki, K.

    2012-06-01

    Microwatt power oscillation devices at sub-terahertz frequency region between 0.3 and 1.0 terahertz (THz) were fabricated from high-Tc superconducting single crystalline Bi2Sr2CaCu2O8+δ and used as a source of the transmission terahertz imaging system. As test examples, terahertz images of coins and a razor blade placed inside the brownish paper envelopes with the spatial resolution of 1 mm are presented. The signal-to-noise ratio exceeds 130 in these images. Using a simple wedge-shaped interferometer and analysing the interference fringe pattern, the wavelength of the terahertz wave is calibrated within 0.1% accuracy. This interferometer also provides a simple method to measure the absorption coefficient of the liquid sample. Two test measurements for distilled water and ethanol are demonstrated and their absorption coefficients are obtained with 99.2% accuracy. This suggests that our terahertz imaging system can be applied to many practical applications, such as biological and biomedical imaging, environmental monitoring, microanalysis of impurities, structure and dynamical analyses of large molecules and ions in solution.

  11. Immobilized rennin in TC/SG composite in cheese production.

    PubMed

    Barouni, Eleftheria; Petsi, Theano; Kolliopoulos, Dionysios; Vasileiou, Dimitrios; Panas, Panagiotis; Bekatorou, Argyro; Kanellaki, Maria; Koutinas, Athanasios A

    2016-06-01

    The object of the current study was to develop a new process for continuous Feta-type cheese production using a biocatalyst consisting of immobilized rennin on a tubular cellulose/starch gel (TC/SG) composite, which has been proven to be an appropriate carrier for enzyme immobilization. Different methodologies were used in order to prepare four biocatalysts. The most effective was selected for cheese production in a 1L continuous system, providing two economically useful results for the dairy industries: (i) increase of productivity by the continuous coagulation of milk, and (ii) saving of the rennin enzyme expenses of the batch coagulation of milk. The criteria used to choose the appropriate biocatalyst was based on the time of coagulation in successive batches, the concentration of immobilized rennin combined with the filter efficiency and its application in the continuous system. Physicochemical analyses of the cheeses at various stages of the ripening were performed. No significant differences compared to cheeses prepared with the traditional method were found. Aroma compounds were determined by SPME GC-MS. PMID:26830563

  12. Subgap Structures in High-Tc Intrinsic Josephson Junctions

    NASA Astrophysics Data System (ADS)

    Müller, Paul

    1998-03-01

    Due to their extremely short coherence length many high-Tc superconductors form natural superconducting multilayers. Adjacent superconducting layers are weakly coupled by the Josephson effect. As a result single crystals act intrinsically as vertical stacks of hundreds of Josephson junctions. We start by summarizing our present state of knowledge, including recent observations of Cherenkov radiation from moving fluxons (G. Hechtfischer, R. Kleiner, A.V. Ustinov, P. Müller, Phys. Rev. Lett. 79, 1365 (1997), and this conference.), and the direct measurement of the (collective) Josephson plasma frequency. We then report on pronounced structures in the current-voltage characteristics of Bi_2Sr_2CaCu_2O8 single crystals, and of Tl_2Ba_2Ca_2Cu_3O_10 thin films. These structures appear well below the superconducting gap, independent on magnetic field and temperatures up to 0.5 T_c(K. Schlenga, G. Hechtfischer, R. Kleiner, W. Walkenhorst, P. Müller, Phys. Rev. Lett. 76, 4943 (1996).). We explain these features by coupling between c-axis phonons and Josephson oscillations(Ch. Helm, Ch. Preis, F. Forsthofer, J. Keller, K. Schlenga, R. Kleiner, P. Müller, Phys. Rev. Lett. 79, 737 (1997).). C-axis lattice vibrations between adjacent superconducting layers are exited by the rf Josephson currents in the resistive state. Our results correspond well to the frequencies of longitudinal c-axis phonons.

  13. 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.

  14. 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.

  15. 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.

  16. Compact spherical neutron polarimeter using high-Tc YBCO films

    NASA Astrophysics Data System (ADS)

    Wang, T.; Parnell, S. R.; Hamilton, W. A.; Li, F.; Washington, A. L.; Baxter, D. V.; Pynn, R.

    2016-03-01

    We describe a simple, compact device for spherical neutron polarimetry measurements at small neutron scattering angles. The device consists of a sample chamber with very low (<0.01 G) magnetic field flanked by regions within which the neutron polarization can be manipulated in a controlled manner. This allows any selected initial and final polarization direction of the neutrons to be obtained. We have constructed a prototype device using high-Tc superconducting films and mu-metal to isolate regions with different magnetic fields and tested device performance in transmission geometry. Finite-element methods were used to simulate the device's field profile and these have been verified by experiment using a small solenoid as a test sample. Measurements are reported using both monochromatic and polychromatic neutron sources. The results show that the device is capable of extracting sample information and distinguishing small angular variations of the sample magnetic field. As a more realistic test, we present results on the characterization of a 10 μm thick Permalloy film in zero magnetic field, as well as its response to an external magnetic field.

  17. Desigualdades por cáncer

    Cancer.gov

    Información básica de las desigualdades en salud por cáncer en EE. UU., factores que contribuyen a la carga desproporcionada del cáncer en algunos grupos y ejemplos de desigualdades en incidencia y mortalidad entre ciertos grupos de la población.

  18. False Negative (99m)Tc-Hydroxymethane Diphosphonate Three-phase Bone Scintigraphy and (99m)Tc-besilesomab Scan in Detecting Tibia Osteomyelitis Concomitant with Necrotizing Fasciitis.

    PubMed

    Tan, Teik Hin; Lee, Boon Nang

    2014-09-01

    We described a case of 51-year-old female patient presented with a right calf necrotising fasciitis (NF) where osteomyelitis (OM) was suspected. (99m)Tc-hydroxymethane diphosphonate three-phase bone scintigraphy and (99m)Tc-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 (99m)Tc-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

  19. 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

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

    PubMed Central

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

    2015-01-01

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

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

    PubMed

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

    2015-09-01

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

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

    PubMed Central

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

    2015-01-01

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

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

    PubMed

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

    2015-10-01

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

  4. 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.

  5. [Activity of ISO/TC212, clinical laboratory testing and in vitro diagnostic test systems].

    PubMed

    Kawai, T

    1998-10-01

    ISO is the International Organization for Standardization, which is a worldwide federation of national standards bodies from 130 countries, one from each country. ISO is a non-governmental organization established in 1947. ISO/TC212, Clinical laboratory testing and in vitro diagnostic test systems was newly established in 1995, consisting of 86 P-members and 12 O-members. ISO/TC212 secretariat is the American National Standards Institute, and NCCLS carries out its secretarial activity. On behalf of the Japanese Industrial Standards Committee (JISC), the Japanese Committee for Clinical Laboratory Standards (JCCLS) serves as the secretariat for the ISO/TC212 National Technical Advisory Group. Three working groups are in the process of preparing the Draft International Standards (DIS) among 9 work items. The next plenary session of ISO/TC212 will be held on May 19-21, 1999 in Tokyo, Japan. PMID:9816905

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

    SciTech Connect

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

    1983-09-01

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

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

    SciTech Connect

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

    1983-09-01

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

  8. Correlation of Tc-99m GSA hepatic studies with biopsies in patients with chronic active hepatitis.

    PubMed

    Tomiguchi, S; Kira, T; Oyama, Y; Nabeshima, M; Nakashima, R; Tsuji, A; Kojima, A; Takahashi, M; Yoshimatsu, S; Sagara, K

    1995-08-01

    To determine whether scintigraphic findings of Tc-99m DTPA-galactosyl-HSA (GSA) correspond to histopathologic findings, Tc-99m GSA hepatic scintigraphy and biopsy were compared in 65 patients with chronic active hepatitis. After injecting 185 MBq of Tc-99m GSA, anterior images were obtained at 5 minutes and 15 minutes. Scintigrams were classified into three grades according to the extent of visualization of the cardiac blood pool on 5 minute and 15 minute images. Biopsies were subjectively graded for findings of necrosis and fibrosis. Scintigraphic grades on 5 minute images were correlated with hepatic necrosis and fibrosis and those on 15-minute images with hepatic fibrosis. Scintigraphic abnormalities of Tc-99m GSA correlated well with histopathologic abnormalities, especially with hepatic fibrosis and necrosis in patients with chronic active hepatitis. PMID:7586877

  9. 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

  10. 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

  11. Production and survival of /sup 99/Tc in He-shell recurrent thermal pulses

    SciTech Connect

    Takahashi, K.; Mathews, G.J.; Ward, R.A.; Becker, S.A.

    1985-05-30

    After a brief introduction to the present state of art of nuclear beta-decay studies in astrophysics, we report our recent work on the long-standing /sup 99/Tc problem. Having combined a detailed study of the recurrent He-shell thermal-pulse, third dredge-up episodes in a 2.25 M/sub solar/ star and an s-process network calculation, we show that a substantial amount of /sup 99/Tc can be produced by the s-process and can survive to be dredged up to the stellar surface. We stress that the factual observation of /sup 99/Tc at the surface of certain stars does not necessarily preclude the /sup 22/Ne(..cap alpha..,n)/sup 25/Mg reaction from remaining as the neutron source for the s-process. The calculated surface abundances of /sup 99/Tc and elements with neighboring atomic numbers are compared with observations. 43 refs., 5 figs.

  12. 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

  13. 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

  14. Cholecystitis: prospective evaluation of sonography and /sup 99m/ Tc-HIDA cholescintigraphy

    SciTech Connect

    Worthen, N.J.; Uszler, J.M.; Funamura, J.L.

    1981-11-01

    Major and minor criteria are determined for sonographic diagnosis of acute and chronic cholecystitis. A prospective study of 113 cases was performed on patients with suspected acute cholecystitis who were evaluated by cholesonography and /sup 99m/Tc-HIDA cholescintigraphy. Data support the use of sonography as the intial imaging procedure for the patient with suspected acute cholecystitis. /sup 99m/Tc-HIDA is useful in those cases without stones which exhibit minor criteria for gallbladder abnormality.

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

    PubMed

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

    2015-06-24

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

  16. 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.

  17. Regional brain uptake and retention of Tc-99m-propylene amine oxime derivatives

    SciTech Connect

    Chaplin, S.B.; Oberle, P.O.; Hoffman, T.J.; Volkert, W.A.; Holmes, R.A.; Nowotnik, D.P.; Pickett, R.D.; Neirinckx, R.

    1985-05-01

    Tc-99m-propylene amine oxime (Tc-99m-PnAO) is a neutral lipophilic chelate that rapidly and passively enters the cerebral cortex (80% on first pass in baboon brain) and then clears exponentially leaving inadequate activity to perform conventional SPECT brain imaging. When side chains are attached to the PnAO backbone lipophilicity is increased, as well as brain retention. In this work the authors evaluated regional brain uptake and retention of Tc-99m-PnAO and several of its derivatives in rat brain using serial autoradiography (ARG). Autoradiographs of each Tc-99m chelate at 5 sec. post peak brain uptake demonstrate discrete grey to white matter differentiation. White matter tracts are well delineated and the darker areas of grey matter appearing in the midbrain and thalamus, corresponding to areas of high capillary density and high blood flow documented with C-14-iodoantipyrine, are easily distinguished. Within 5 min. of the peak uptake the regional uptake and grey/white differentiation is lost on the Tc-99m-PnAO ARG. In contrast the 5 min. ARG of the more lipophilic Tc-99m, chelate with dimethyl-PnAO (DMPnAO) shows the complete reverse of the 5 sec. ARG, with greater activity in the white matter tracts than in the grey matter. One of the derivatives, tetramethyl-PAO (TMPAO) complexed with Tc-99m is retained in the grey matter of rat brain and shows persistent grey to white localization for at least 60 min., analogous to what has been reported with I-123-IMP. These results suggest that Tc-99m-TMPAO or one of its derivatives may be appropriate for SPECT imaging of cerebral blood flow abnormalities.

  18. Structural, electronic, superconducting and mechanical properties of ReC and TcC

    SciTech Connect

    Kavitha, M.; Priyanga, G. Sudha; Rajeswarapalanichamy, R. Santhosh, M.

    2015-06-24

    The structural, electronic, superconducting and mechanical properties of ReC and TcC are investigated using density functional theory calculations. The lattice constants, bulk modulus, and the density of states are obtained. The calculated lattice parameters are in good agreement with the available results. The density of states reveals that ReC and TcC exhibit metallic behavior at ambient condition. A pressure-induced structural phase transition is observed in both materials.

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

    SciTech Connect

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

    1983-11-01

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

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

    SciTech Connect

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

    1980-06-01

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

  1. Is Brown Adipose Tissue Visualization Reliable on 99mTc-Methoxyisobutylisonitrile Diagnostic SPECT Scintigraphy?

    PubMed

    Haghighatafshar, Mahdi; Farhoudi, Farinaz

    2016-01-01

    The 99mTc-MIBI has been used with great value as a diagnostic technique in patients with primary hyperparathyroidism. False-positive scans may occur due to misinterpretation of the physiologic distribution of the 99mTc-MIBI. Reviewing consecutive SPECT scans, we evaluated this possibility and assessed how frequently brown adipose tissue (BAT) is seen on 99mTc-MIBI scintigraphy. Here, we retrospectively reviewed scans of consecutive patients who were evaluated for parathyroid adenomas from March 2015 to June 2015, using dual-phase (early and delayed) planar imaging and SPECT. We identified 60 patients (48 female and 12 male; mean age, 52.25 ± 15.20 years; range, 22-86 years).We detected the presence of 99mTc-MIBI uptake in BAT in 20 of 60 patients (33.33%) in the neck. Although the patients with T99mc-MIBI uptake in BAT were younger (mean age, 48.85 ± 15.27 years, range, 26-73 years) than the patients with no 99mTc-MIBI uptake (mean age, 53.95 ± 15.07 years, range, 22-86 years), this difference was not statistically significant (P = 0.224). The percentage of female patients with BAT detection was higher (17/48 patients; 37.5%) than that of the male population (3/12 patients; 25%), this difference was not also statistically significant (P = 0.85).In patient population referred to 99mTc MIBI scintigraphy of the parathyroid glands, uptake of 99mTc-MIBI in BAT should not be misinterpreted with 99mTc-MIBI-avid-tumors. Fused SPECT/CT images (not SPECT-only) are necessary to distinguish BAT from bone, muscle, thyroid, myocardium, parathyroids, and other structures in the neck and chest. PMID:26765463

  2. Structural, electronic, superconducting and mechanical properties of ReC and TcC

    NASA Astrophysics Data System (ADS)

    Kavitha, M.; Priyanga, G. Sudha; Rajeswarapalanichamy, R.; Santhosh, M.

    2015-06-01

    The structural, electronic, superconducting and mechanical properties of ReC and TcC are investigated using density functional theory calculations. The lattice constants, bulk modulus, and the density of states are obtained. The calculated lattice parameters are in good agreement with the available results. The density of states reveals that ReC and TcC exhibit metallic behavior at ambient condition. A pressure-induced structural phase transition is observed in both materials.

  3. The prevalence and distribution of Th17 and Tc17 cells in patients with thyroid tumor.

    PubMed

    Jiang, Guoqin; Ma, Shoubao; Wei, Yan; Wu, Yan; Yu, Xiao; Liu, Haiyan

    2014-11-01

    Both Th17 and Tc17 cells have been found in various tumors and may play important roles in regulating anti-tumor immune responses. However, the prevalence and distribution of Th17 and Tc17 cells in thyroid tumors are still unclear. In the current study, we examined the percentages of Th17 and Tc17 cells in the peripheral blood of 31 thyroid adenoma and 11 thyroid carcinoma patients. The serum IL-17 levels were also examined and their associations with Th17 and Tc17 cells were evaluated. Moreover, the presence of Th17 cells was detected in both thyroid adenoma and carcinoma patients. Our results showed that compared with healthy individuals, patients with thyroid tumors had a higher proportion of Th17 and lower proportion of Tc17 cells in peripheral blood. The serum concentration of IL-17 was significantly increased in patients with thyroid tumors and it was correlated with the percent of Th17 cells. Furthermore, the number of Th17 cells was significantly increased in the tumors of the patients. Th17 and Tc17 cells were negatively correlated with the tumor size. There was no significant difference between thyroid adenoma and carcinoma patients. These results indicate that Th17 cells may contribute to thyroid tumor pathogenesis. PMID:25068436

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

    SciTech Connect

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

    2006-12-04

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

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

    SciTech Connect

    Paviet-Hartmann, P.

    2002-02-25

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

  6. Field-Scale Migration of 99Tc and 129I at the Nevada Test Site

    SciTech Connect

    Hu, Q; Smith, D K

    2004-03-29

    The groundwater at the Nevada Test Site (NTS) contains many long-lived radionuclides, including {sup 99}Tc (technetium) and {sup 129}I (iodine), as a result of 828 underground nuclear weapons tests conducted between 1951 and 1992. We synthesized a body of data collected on the distribution of {sup 99}Tc and {sup 129}I in groundwater to assess their migration at NTS, at field scales over distances of hundreds of meters and for durations up to forty years and under hydrogeologic conditions very similar to the proposed geological repository at Yucca Mountain. The results of our study show that Tc does not necessarily exist as a mobile and conservative species TcO{sub 4}{sup -}, as has been commonly assumed. This conclusion is corroborated by recent in situ redox potential measurements, which show that groundwaters at multiple locations of the NTS are not oxidizing, and mobility of reduced Tc species (TcO{sub 2} {center_dot} nH{sub 2}O) is greatly decreased. Speciation of iodine and its associated reactivity is also complex in the groundwater at the NTS, and its effect on the mobility of iodine should be the subject of future studies.

  7. [Delayed Tc-99m-PMT imaging in the specific diagnosis of hepatocellular carcinoma].

    PubMed

    Wu, Z M

    1988-09-01

    The results of Tc-99m-PMT imaging on 100 patients with various malignant and benign hepatic diseases verified histologically (73 hepatocellular carcinoma, 3 liver cell adenoma, 1 cholangiocarcinoma, 5 metastatic liver carcinoma, 2 liver cyst, 12 hemangioma, 1 fatty degeneration, 1 liver regeneration, 1 postoperative liver fibrosis and 1 liver cirrhosis) are reported. All lesions appeared as decreased radioactivity or "cold" defect region on early Tc-99m-PMT imaging, rendering it valuable for the diagnosis of tumor localization. In 92 (95.8%) of the 96 patients with various hepatic tumors and 25 (86.2%) of the 29 patients with small hepatocellular carcinoma (less than 5 cm), the tumors were localized by early Tc-99m-PMT imaging. In 14 of the 73 patients with established hepatocellular carcinoma, the tumors gave greater radioactivity than that of the surrounding liver tissues, whereas in 31 patients the radioactivity of the tumor equalled the normal liver on delayed Tc-99m-PMT imaging (positive rate 61.6%). There was no significant difference between the positive rates of serum AFP level and the tumor size shown by delayed Tc-99m-PMT imaging in hepatocellular carcinomas. The radioactivity in 3 liver cell adenoma patients was similar to the gallbladder. No false positive result was seen in the other malignant and benign hepatic tumors. This study indicates that delayed Tc-99m-PMT imaging is highly specific in the diagnosis of hepatocellular carcinoma. PMID:2854779

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

    NASA Astrophysics Data System (ADS)

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

    2014-03-01

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

  9. Evaluation of separate renal function by means of 99mTc-aprotinin uptake test

    SciTech Connect

    Aprile, C.; Saponaro, R.; Villa, G.; Carena, M.; Chiari, G.; Salvadeo, A.; Lunghi, F.; Piazza, V.

    1986-01-01

    The possibility that relative kidney uptake of technetium-99m aprotinin (TcA) might be indicative of separate renal function was investigated in 89 patients who underwent both effective renal plasma flow (ERPFs) and glomerular filtration rate (GFR) determination. A reference group consisted of 27 healthy volunteers, studied only with TcA. The correlation with ERPFs (r = .73) was similar to that previously reported and confirmed. The correlation with GFR (r = .68) was better if a subgroup of renal units with TcA uptake lower than 16% (lower normal limit) was considered. Most likely, glomerular filtration is a limiting factor of the tubular uptake of TcA, and when GFR is reduced, both parameters decrease in the same manner, while if GFR is normal the two parameters are relatively independent. The correlation between TcA and GFR in 32 children was very similar to that found in adults. TcA uptake test seems to be a useful indicator of separate renal function, providing morphological information at, the same time.

  10. 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

  11. Molybdenum target specifications for cyclotron production of 99mTc based on patient dose estimates

    NASA Astrophysics Data System (ADS)

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

    2016-01-01

    In response to the recognized fragility of reactor-produced 99Mo supply, direct production of 99mTc via 100Mo(p,2n)99mTc reaction using medical cyclotrons has been investigated. However, due to the existence of other Molybdenum (Mo) isotopes in the target, in parallel with 99mTc, other technetium (Tc) radioactive isotopes (impurities) will be produced. They will be incorporated into the labeled radiopharmaceuticals and result in increased patient dose. The isotopic composition of the target and beam energy are main factors that determine production of impurities, thus also dose increases. Therefore, they both must be considered when selecting targets for clinical 99mTc production. Although for any given Mo target, the patient dose can be predicted based on complicated calculations of production yields for each Tc radioisotope, it would be very difficult to reverse these calculations to specify target composition based on dosimetry considerations. In this article, a relationship between patient dosimetry and Mo target composition is studied. A simple and easy algorithm for dose estimation, based solely on the knowledge of target composition and beam energy, is described. Using this algorithm, the patient dose increase due to every Mo isotope that could be present in the target is estimated. Most importantly, a technique to determine Mo target composition thresholds that would meet any given dosimetry requirement is proposed.

  12. High Affinity Immobilization of Proteins Using the CrAsH/TC Tag.

    PubMed

    Schulte-Zweckel, Janine; Rosi, Federica; Sreenu, Domalapally; Schröder, Hendrik; Niemeyer, Christof M; Triola, Gemma

    2016-01-01

    Protein microarrays represent important tools for biomedical analysis. We have recently described the use of the biarsenical-tetracysteine (TC) tag for the preparation of protein microarrays. The unique feature of this tag enables the site-specific immobilization of TC-containing proteins on biarsenical-modified surfaces, resulting in a fluorescence enhancement that allows the direct quantification of the immobilized proteins. Moreover, the reversibility of the binding upon incubation with large quantities of thiols permits the detachment of the proteins from the surface, thereby enabling recovery of the substrate to extend the life time of the slide. Herein, we describe our recent results that further extend the applicability of the CrAsH/TC tag to the fabrication of biochips. With this aim, the immobilization of proteins on surfaces has been investigated using two different spacers and two TC tags, the minimal TC sequence (CCPGCC) and an optimized motif (FLNCCPGCCMEP). While the minimal peptide motif enables a rapid recycling of the slide, the optimized TC sequence reveals an increased affinity due to its greater resistance to displacement by thiols. Moreover, the developed methodology was applied to the immobilization of proteins via on-chip ligation of recombinant protein thioesters. PMID:27338319

  13. High-Tc SQUID Magnetometers for Industrial Applications

    NASA Astrophysics Data System (ADS)

    Diiorio, Mark; Yang, Kai-Yueh; Yoshizumi, Shozo; Haupt, Steven; Haran, Don; Koch, Roger; Lathrop, Dan; Trammel, Hoke

    1998-03-01

    We have developed high-Tc SQUID magnetometers for use in a variety of industrial applications. Relatively inexpensive direct-coupled magnetometers have been developed for low-frequency applications including fetal-magnetocardiography. A manufacturable process has been developed to reproducibly fabricate high-resistance (up to 6 Ω) SNS step-edge junctions with YBa_2Cu_3O_7-x as the superconductor and Ag-Au alloy as the normal metal. Magnetic field sensitivities at 77K of 22 ft/Hz^1/2 at 1 KHz and 32 ft/Hz^1/2 at 1 Hz have been achieved in a well-shielded laboratory environment. Current effort is focused on operation in an unshielded environment using flux dams(Milliken et al. Appl. Phys. Lett. 71 1857 (1997)) in conjunction with narrow superconducting pickup coils placed in parallel. An integrated magnetometer process has also been optimized for use in high-frequency applications. The integrated megnetometer utilizes two layers of YBa_2Cu_3O_7-x and one layer of deposited SrTiO_3, all on the same 24 mm x 5 mm substrate. The applications under development include the detection of the explosive material in non-metallic land mines using nuclear quadrupole resonance as well as the non-destructive evaluation of non-metallic composites using nuclear magnetic resonance. For operation in the MHz regime, these applications demand a high quality insulator layer and a robust SQUID that can withstand high current transients.

  14. Structural Insights into the PorK and PorN Components of the Porphyromonas gingivalis Type IX Secretion System

    PubMed Central

    Gorasia, Dhana G.; Veith, Paul D.; Hanssen, Eric G.; Glew, Michelle D.; Sato, Keiko; Yukitake, Hideharu; Nakayama, Koji; Reynolds, Eric C.

    2016-01-01

    The type IX secretion system (T9SS) has been recently discovered and is specific to Bacteroidetes species. Porphyromonas gingivalis, a keystone pathogen for periodontitis, utilizes the T9SS to transport many proteins including the gingipain virulence factors across the outer membrane and attach them to the cell surface via a sortase-like mechanism. At least 11 proteins have been identified as components of the T9SS including PorK, PorL, PorM, PorN and PorP, however the precise roles of most of these proteins have not been elucidated and the structural organization of these components is unknown. In this study, we purified PorK and PorN complexes from P. gingivalis and using electron microscopy we have shown that PorN and the PorK lipoprotein interact to form a 50 nm diameter ring-shaped structure containing approximately 32–36 subunits of each protein. The formation of these rings was dependent on both PorK and PorN, but was independent of PorL, PorM and PorP. PorL and PorM were found to form a separate stable complex. PorK and PorN were protected from proteinase K cleavage when present in undisrupted cells, but were rapidly degraded when the cells were lysed, which together with bioinformatic analyses suggests that these proteins are exposed in the periplasm and anchored to the outer membrane via the PorK lipid. Chemical cross-linking and mass spectrometry analyses confirmed the interaction between PorK and PorN and further revealed that they interact with the PG0189 outer membrane protein. Furthermore, we established that PorN was required for the stable expression of PorK, PorL and PorM. Collectively, these results suggest that the ring-shaped PorK/N complex may form part of the secretion channel of the T9SS. This is the first report showing the structural organization of any T9SS component. PMID:27509186

  15. Structural Insights into the PorK and PorN Components of the Porphyromonas gingivalis Type IX Secretion System.

    PubMed

    Gorasia, Dhana G; Veith, Paul D; Hanssen, Eric G; Glew, Michelle D; Sato, Keiko; Yukitake, Hideharu; Nakayama, Koji; Reynolds, Eric C

    2016-08-01

    The type IX secretion system (T9SS) has been recently discovered and is specific to Bacteroidetes species. Porphyromonas gingivalis, a keystone pathogen for periodontitis, utilizes the T9SS to transport many proteins including the gingipain virulence factors across the outer membrane and attach them to the cell surface via a sortase-like mechanism. At least 11 proteins have been identified as components of the T9SS including PorK, PorL, PorM, PorN and PorP, however the precise roles of most of these proteins have not been elucidated and the structural organization of these components is unknown. In this study, we purified PorK and PorN complexes from P. gingivalis and using electron microscopy we have shown that PorN and the PorK lipoprotein interact to form a 50 nm diameter ring-shaped structure containing approximately 32-36 subunits of each protein. The formation of these rings was dependent on both PorK and PorN, but was independent of PorL, PorM and PorP. PorL and PorM were found to form a separate stable complex. PorK and PorN were protected from proteinase K cleavage when present in undisrupted cells, but were rapidly degraded when the cells were lysed, which together with bioinformatic analyses suggests that these proteins are exposed in the periplasm and anchored to the outer membrane via the PorK lipid. Chemical cross-linking and mass spectrometry analyses confirmed the interaction between PorK and PorN and further revealed that they interact with the PG0189 outer membrane protein. Furthermore, we established that PorN was required for the stable expression of PorK, PorL and PorM. Collectively, these results suggest that the ring-shaped PorK/N complex may form part of the secretion channel of the T9SS. This is the first report showing the structural organization of any T9SS component. PMID:27509186

  16. Tc17 cells are a proinflammatory, plastic lineage of pathogenic CD8+ T cells that induce GVHD without antileukemic effects.

    PubMed

    Gartlan, Kate H; Markey, Kate A; Varelias, Antiopi; Bunting, Mark D; Koyama, Motoko; Kuns, Rachel D; Raffelt, Neil C; Olver, Stuart D; Lineburg, Katie E; Cheong, Melody; Teal, Bianca E; Lor, Mary; Comerford, Iain; Teng, Michele W L; Smyth, Mark J; McCluskey, James; Rossjohn, Jamie; Stockinger, Brigitta; Boyle, Glen M; Lane, Steven W; Clouston, Andrew D; McColl, Shaun R; MacDonald, Kelli P A; Hill, Geoffrey R

    2015-09-24

    IL-17-producing cells are important mediators of graft-versus-host disease (GVHD) after allogeneic stem cell transplantation (SCT). Here we demonstrate that a distinct CD8(+) Tc17 population develops rapidly after SCT but fails to maintain lineage fidelity such that they are unrecognizable in the absence of a fate reporter. Tc17 differentiation is dependent on alloantigen presentation by host dendritic cells (DCs) together with IL-6. Tc17 cells express high levels of multiple prototypic lineage-defining transcription factors (eg, RORγt, T-bet) and cytokines (eg, IL-17A, IL-22, interferon-γ, granulocyte macrophage colony-stimulating factor, IL-13). Targeted depletion of Tc17 early after transplant protects from lethal acute GVHD; however, Tc17 cells are noncytolytic and fail to mediate graft-versus-leukemia (GVL) effects. Thus, the Tc17 differentiation program during GVHD culminates in a highly plastic, hyperinflammatory, poorly cytolytic effector population, which we term "inflammatory iTc17" (iTc17). Because iTc17 cells mediate GVHD without contributing to GVL, therapeutic inhibition of iTc17 development in a clinical setting represents an attractive approach for separating GVHD and GVL. PMID:26206951

  17. 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-α, 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-α, 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

  18. 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.

  19. Lassen's equation is a good approximation of permeability-surface model: new α values for 99mTc-HMPAO and 99mTc-ECD

    PubMed Central

    Kameyama, Masashi

    2014-01-01

    Brain perfusion tracers like [99mTc] d,l-hexamethyl-propyeneamine oxime (99mTc-HMPAO) and [99mTc] ethyl-cysteinate dimer (99mTc-ECD) underestimate regional cerebral blood flow (rCBF) at high flow values. To improve linearity between tracer accumulation and rCBF, two different models have been proposed. One is Lassen's correction algorithm for back-diffusion of tracer, and the other is based on the permeability-surface (PS) model for correction of low first-pass extraction. Although both these models have the same goal, they have completely different forms of equation. It was demonstrated that mathematical approximation of the PS model equation leads to Lassen's equation. In this process, the relationship between PS, CBF values and Lassen's parameter was acquired, and how to correct both the back-diffusion and low first-pass extraction was also demonstrated. A computer simulation confirmed that the two models provided similar consequences when the parameter value is chosen according to the relationship found. Lassen's equation can be used to correct not only back-diffusion but also low first-pass extraction. To perform overall correction, the parameter value we have been using for decades may be too weak. I estimated that the parameter value for overall correction of HMPAO would be around 0.5, and that of ECD would be around 0.65. PMID:24736892

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

    SciTech Connect

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

    2004-03-17

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

  1. 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

  2. Se77 NMR investigation of the KxFe2-ySe2 high-Tc superconductor (Tc=33 K)

    NASA Astrophysics Data System (ADS)

    Torchetti, D. A.; Fu, M.; Christensen, D. C.; Nelson, K. J.; Imai, T.; Lei, H. C.; Petrovic, C.

    2011-03-01

    We report comprehensive Se77 NMR measurements on a single crystalline sample of the recently discovered FeSe-based high-temperature superconductor KxFe2-ySe2 (Tc=33 K) in a broad temperature range up to 290 K. Despite deviations from the stoichiometric KFe2Se2 composition, we observed Se77 NMR line shapes as narrow as 4.5 kHz under a magnetic field applied along the crystal c axis, and found no evidence for co-existence of magnetic order with superconductivity. On the other hand, the Se77 NMR line shape splits into two peaks with equal intensities at all temperatures when we apply the magnetic field along the ab plane. This suggests that K vacancies may have a superstructure and that the local symmetry of the Se sites is lower than the tetragonal fourfold symmetry of the average structure. This effect might be a prerequisite for stabilizing the s± symmetry of superconductivity in the absence of the hole bands at the Brillouin zone center. From the increase of NMR linewidth below Tc induced by the Abrikosov lattice of superconducting vortices, we estimate the in-plane penetration depth λab~290 nm and the carrier concentration ne~1×10+21 cm-3. Our Knight shift 77K data indicate that the uniform spin susceptibility decreases progressively with temperature, in analogy with the case of FeSe (Tc~9 K) as well as other FeAs high-Tc systems. The strong suppression of 77K observed immediately below Tc for all crystal orientations is consistent with a singlet pairing of Cooper pairs. We do not however observe the Hebel-Slichter coherence peak of the nuclear spin-lattice relaxation rate 1/T1 immediately below Tc, expected for conventional BCS s-wave superconductors. In contrast with the case of FeSe, we do not observe evidence for an enhancement of low-frequency antiferromagnetic spin fluctuations near Tc in 1/T1T. Instead, 1/T1T exhibits qualitatively the same behavior as overdoped non-superconducting Ba(Fe1-xCox)2As2 with x~0.14 or greater, where hole bands are missing in

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

    PubMed

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

    2015-01-01

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

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

    SciTech Connect

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

    2010-07-15

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

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

    PubMed

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

    2013-05-01

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

  6. [A new radiopharmaceutical for bone imaging: experimental study of 99mTc-HEDTMP].

    PubMed

    Hu, Shu; Deng, Houfu; Jiang, Shubin; Luo, Shunzhong; Lei, Yong

    2010-08-01

    The purpose of this study is to prepare 99mTc-HEDTMP [N-(2-hydroxyethyl) ethlenediamine-1,1,2-tri (methylene phosphonic acid), a new kind of bone seeking compound; to investigate its biological properties; and to explore the possibility of using it as a potential radiopharmaceutical for skeleton scintigraphy. HEDTMP was labeled with 99mTc by "pretinning" method, the radiochemical purity was 97.00% +/- 0.34%. 99mTc-HEDTMP was found to be stable in 5 hours in vitro with the radiochemical purity over 95% even after being diluted by physiological saline with the factor of dilution 100. The plane bone scanning of rabbits showed that 99mTc-HEDTMP was principally absorbed by skeletal system. Skull, spine and legs could be observed clearly, and were more legible than the images of 99mTc-MDP. Mice trial also indicated the high bone seeking of 99mTc-HEDTMP. The skeletal uptake was 11.92% ID/g, 13.19% ID/g, 10.14% ID/g, 10.04% ID/g, 7.71% ID/g separately at 30 minutes, 1 hour, 3 hours, 6 hours and 24 hours after the injection. Kidney seemed to be the major excretory organ. The clearance of blood was quick and the retaining amount in non-target organs was small. These results indicate that 99mTc-HEDTMP can be prepared easily, and its biological properties can be compared favorably with the commonly used bone imaging agent, and it is well worth further researching as a promising potential radiopharmaceutical in nuclide diagnosis for skeleton diseases. PMID:20842850

  7. Evaluation of the Allergenicity Potential of TcPR-10 Protein from Theobroma cacao

    PubMed Central

    Cardoso, Thyago Hermylly Santana; Pirovani, Carlos Priminho; Micheli, Fabienne; Noronha, Fátima Soares Motta; Alves, Andréa Catão; Faria, Ana Maria Caetano; da Silva Gesteira, Abelmon

    2012-01-01

    Background The pathogenesis related protein PR10 (TcPR-10), obtained from the Theobroma cacao-Moniliophthora perniciosa interaction library, presents antifungal activity against M. perniciosa and acts in vitro as a ribonuclease. However, despite its biotechnological potential, the TcPR-10 has the P-loop motif similar to those of some allergenic proteins such as Bet v 1 (Betula verrucosa) and Pru av 1 (Prunus avium). The insertion of mutations in this motif can produce proteins with reduced allergenic power. The objective of the present work was to evaluate the allergenic potential of the wild type and mutant recombinant TcPR-10 using bioinformatics tools and immunological assays. Methodology/Principal Findings Mutant substitutions (T10P, I30V, H45S) were inserted in the TcPR-10 gene by site-directed mutagenesis, cloned into pET28a and expressed in Escherichia coli BL21(DE3) cells. Changes in molecular surface caused by the mutant substitutions was evaluated by comparative protein modeling using the three-dimensional structure of the major cherry allergen, Pru av 1 as a template. The immunological assays were carried out in 8–12 week old female BALB/c mice. The mice were sensitized with the proteins (wild type and mutants) via subcutaneous and challenged intranasal for induction of allergic airway inflammation. Conclusions/Significance We showed that the wild TcPR-10 protein has allergenic potential, whereas the insertion of mutations produced proteins with reduced capacity of IgE production and cellular infiltration in the lungs. On the other hand, in vitro assays show that the TcPR-10 mutants still present antifungal and ribonuclease activity against M. perniciosa RNA. In conclusion, the mutant proteins present less allergenic potential than the wild TcPR-10, without the loss of interesting biotechnological properties. PMID:22768037

  8. 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 β-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

  9. The trajectory and impact circumstances of asteroid 2008 TC3

    NASA Astrophysics Data System (ADS)

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

    2010-05-01

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

  10. ISO TC211 standards on Provenance for Earth science

    NASA Astrophysics Data System (ADS)

    Di, L.; Deng, M.

    2014-12-01

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

  11. ECT imaging with Tc(V)-99m dimercaptosuccinic acid useful to detect lung metastases of osteosarcoma

    SciTech Connect

    Ohta, H.; Ishii, M.; Yoshizumi, M.; Endo, K.; Fujita, T.; Nakajima, T.; Sakahara, H.; Torizuka, K.; Kotoura, Y.; Yokoyama, A.

    1985-01-01

    ECT imaging, using Tc(V)-99m dimercaptosuccinic acid (Tc(V)-DMS) was performed in two patients with lung metastasis of osteosarcoma, and the results were compared with those of CT scan. Clear accumulation of Tc(V)-DMS was recognized in all cases in the same area that CT scans demonstrated. Tc(V)-DMS was labeled under optimal pH 8, had very low SnCl/sub 2/ concentrations, an equilibrium between a stable form and a dissociated form of anion TcO/sub 4/(3-) structurally similar to PO/sub 4/(3-), and was postulated for tumor uptake. Considering this proposed mechanism for Tc(V)-DMS uptake by tumor cells, ECT imaging using this tracer could be of use in the early detection of lung metastasis of osteosarcoma.

  12. The unusually high Tc in rare-earth-doped single crystalline CaFe2As2

    NASA Astrophysics Data System (ADS)

    Wei, Fengyan; Lv, Bing; Deng, Liangzi; Meen, James K.; Xue, Yu-Yi; Chu, Ching-Wu

    2014-08-01

    In rare-earth-doped single crystalline CaFe2As2, the mysterious small volume fraction which superconducts up to 49 K, much higher than the bulk Tc ~ 30 s K, has prompted a long search for a hidden variable that could enhance the Tc by more than 30% in iron-based superconductors of the same structure. Here we report a chemical, structural and magnetic study of CaFe2As2 systematically doped with La, Ce, Pr and Nd. Coincident with the high Tc phase, we find extreme magnetic anisotropy, accompanied by an unexpected doping-independent Tc and equally unexpected superparamagnetic clusters associated with As vacancies. These observations lead us to conjecture that the tantalizing Tc enhancement may be associated with naturally occurring chemical interfaces and may thus provide a new paradigm in the search for superconductors with higher Tc.

  13. 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

  14. Effect of Van Hove singularities on high-Tc superconductivity in H3S

    NASA Astrophysics Data System (ADS)

    Sano, Wataru; Koretsune, Takashi; Tadano, Terumasa; Akashi, Ryosuke; Arita, Ryotaro

    2016-03-01

    One of the interesting open questions for the high-transition-temperature (Tc) superconductivity in sulfur hydrides is why high-pressure phases of H3S have extremely high Tc's. Recently, it has been pointed out that the presence of the Van Hove singularities (VHS) around the Fermi level is crucial. However, while there have been quantitative estimates of Tc based on the Migdal-Eliashberg theory, the energy dependence of the density of states (DOS) has been neglected to simplify the Eliashberg equation. In this study, we go beyond the constant DOS approximation and explicitly consider the electronic structure over 40 eV around the Fermi level. In contrast with the previous conventional calculations, this approach with a sufficiently large number of Matsubara frequencies enables us to calculate Tc without introducing the empirical pseudo Coulomb potential. We show that while H3S has much higher Tc than H2S for which the VHS is absent, the constant DOS approximation employed so far seriously overestimates (underestimates) Tc by ˜60 K (˜10 K) for H3S (H2S ). We then discuss the impact of the strong electron-phonon coupling on the electronic structure with and without the VHS and how it affects the superconductivity. In particular, we focus on (1) the feedback effect in the self-consistent calculation of the self-energy, (2) the effect of the energy shift due to the zero-point motion, and (3) the effect of the changes in the phonon frequencies due to strong anharmonicity. We show that the effect of (1)-(3) on Tc is about 10-30 K for both H3S and H2S . Eventually, Tc is estimated to be 181 K for H3S at 250 GPa and 34 K for H2S at 140 GPa, which explains the pressure dependence of Tc observed in the experiment. In addition, we evaluate the lowest-order vertex correction beyond the Migdal-Eliashberg theory and discuss the validity of the Migdal approximation for sulfur hydrides.

  15. Effects of ligand structure on the lipophilicity and biodistribution of Tc-99m-amine oxime chelates

    SciTech Connect

    Volkert, W.A.; McKenzie, E.; Hoffman, T.J.; Troutnert, D.E.; Holmes, R.A.

    1984-01-01

    Propylene amine oxime (PnAO) or 3,3'-(1-3-propanediyl-diimino) bis(3-methyl-2-butanone) dioxime, forms a neutral-lipid soluble Tc-99m-chelate in aqueous solutions. When injected it efficiently crosses the intact normal blood-brain-barrier (BBB) with approximately 80% extracted on first transit in baboon brain at normal cerebral blood flow (50 ml/min/100g). In this study the authors evaluated the effects of altered ligand structure (backbone) on the physical properties and biodistribution of several different Tc-99m amine oxime chelates in rodents. Three analogues of PnAO were evaluated: ethyleneamine oxime (EnAO), butylene-amine (BnAO), and amine oxime (AO). Each formed a neutral Tc-99m complex, determined by electrophoresis. Their octanol/saline partition coefficients were distinctly different with Tc-99m-BnAO (0.49 +- 0.09) and Tc-99m-AO (0.07 +- 0.02) being significantly less than Tc-99m-PnAO (44.3 +- 4.9). It was not possible to prepare Tc-99m-EnAO in aqueous solution as a single chemical species but when the complex was injected into rats it localized in normal brain almost identical to Tc-99m-PnAO. Both Tc-99m-AO and Tc-99m-BnAO failed to exhibit any detectable brain uptake and were both rapidly excreted through the kidneys and liver. These results show that slight structural modifications of the ligand backbone can significantly alter chelate lipid solubility and brain extraction. This infers that Tc-99m-AO and - BnAO have complex structures that are distinctly different from Tc-99m-PnAO and -EnAO.

  16. Dynamic Jahn-Teller Coupling, Anharmonic Oxygen Vibrations and HIGH-Tc Superconductivity in Oxides

    NASA Astrophysics Data System (ADS)

    Johnson, K. H.; Clougherty, D. P.; McHenry, M. E.

    A universal dynamic Jahn-Teller (DJT) mechanism for superconductivity and its applications to CuO and BaBiO3 high-Tc oxides are reviewed. Dynamical interconversion between the shallow "double-well" potentials of degenerate delocalized oxygen-oxygen "pπ-bonds" at the Fermi energy (EF) induces anharmonic oxygen vibrations, lattice-electron coupling, and Cooper pairing. This mechanism yields high Tc's and small-to-vanishing isotope shifts for cuprates, where O(pπ)-O(pπ) bond overlap at EF is promoted by Cu(dπ*)-O(pπ) hybridization. It yields lower Tc's and larger isotope shifts for BaBiO3's, where O(pπ)-O(pπ) overlap is small. For vanishing bond overlap at EF, DJT coupling reduces to harmonic phonon coupling in BCS theory. Simple formulae for calculating Tc and isotope shifts for any superconductor from the "real-space" chemical bonding at EF are presented, yielding (Tc)max ≈ 230 K.

  17. Vesicoureteral Reflux Detected with 99mTc-DTPA Renal Scintigraphy during Evaluation of Renal Function

    PubMed Central

    Manevska, Nevena; Stojanoski, Sinisa; Majstorov, Venjamin; Pop-Gjorcheva, Daniela; Zdraveska, Nikolina; Kuzmanovska, Dafina

    2016-01-01

    BACKGROUND: Radionuclide techniques, as direct radionuclide cystography and 99mTc-DMSA scintigraphy, have been used in evaluation of vesicoureteral reflux (VUR) and reflux nephropathy (RN) in children. Dynamic 99mTc-DTPA scintigraphy is reserved for evaluation of differential renal function and obstruction in children, where hydronephrosis is detected by ultrasonography (US) pre- or postnatally. CASE REPORT: Six year old boy was prenatally diagnosed with bilateral hydronephrosis. Postnatal, severe bilateral VUR was detected by voiding urethrocytography. US and 99mTc-DTPA scintigraphy performed in the first month of life showed small left kidney that participated with 2% in the global renal function. Bilateral cutaneous ureterostomy has been performed in order to obtain good renal drainage and promote optimal renal growth. Twelve months later, classic antireflux procedure was done. Control 99mTc-DTPA scintigraphy, 5 ys after antireflux surgery, revealed persisting radioactivity during the diuretic phase, in the left kidney that indicated antireflux procedure failure with VUR reappearance. CONCLUSION: 99mTc-DTPA scintigraphy is the first method of choice for long-term monitoring of individual kidney function in children with VUR and other congenital urinary tract anomalies. Additionally, it can be used as indirect radionuclide cystography when rising of radioactivity in the kidney region, during the diuretic phase can indicate presence of VUR. PMID:27275347

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

    SciTech Connect

    Paviet-Hartmann, P.

    2001-01-01

    Technetium is one of the most prominent problems since its most stable specie in the environment, the pertechnetate ion, is highly mobile and considered as a long-term hazard in nuclear waste disposal. Because of the small activities of 99Tc relative to other fission products 137Cso r 90Sr,a nd its long half-life time (t1/2 = 2.1{center_dot}10{sup 5} yrs), 99Tci s one of the key isotopes that should always be analyzed in the radioactive liquid waste streams from the reprocessing industry where the largest concentrations are to be expected. Furthermore, as a pure beta-emitter, Tc has to be isolated from the intermediate level waste (ILW) stream prior to any measurement in such complex media. We have developed a method for 99Tc extraction providing recommendations that will be useful for extracting it from acid and basic ILW. The extraction of 99Tc from L W by dibenzo-18-crown-6 (DB18C6) has been investigated and a simplex optimization of key parameters involved in the procedure has allowed us to set up their best values. Experiments have been carried out on synthetic and real effluents from La Hague reprocessing plant, France, and results show that DB18C6 is highly selective towards 99Tc. The application of this procedure has been successfully demonstrated through the analysis of actual waste streams coming from two reprocessing plants at La Hague and Marcoule, France.

  19. Biodistribution and pharmacokinetics of the (99m)Tc labeled human elastase inhibitor, elafin, in rats.

    PubMed

    Kaschwich, Mark; Lützen, Ulf; Zhao, Yi; Tjiong, Angelina; Marx, Marlies; Haenisch, Sierk; Wiedow, Oliver; Preuss, Stefanie; Culman, Juraj; Zuhayra, Maaz

    2016-04-01

    Elafin is a potent reversible inhibitor of the pro-inflammatory proteases leukocyte elastase and protease 3. It is currently in clinical development for the use in postoperative inflammatory diseases. We investigated the pharmacokinetics of (99m)Tc-labeled elafin ((99m)Tc-Elafin) in blood and individual organs in rat after bolus intravenous injection using the single photon emission tomography (SPECT). (99m)Tc-Elafin predominantly accumulated in the kidney reaching a maximum of 8.5% ± 0.1% of the injected dose per gram (ID/g) at 5 min post injection (p.i) and decreased only slowly during 24 h. In contrast, the initially high radio activity recorded in the other organs rapidly decreased parallel to the radioactivity detected in blood. The blood kinetics fits to a two compartment kinetics model. The radio activity in the dissected kidney was 4.98 ± 1.24%ID/g 24 h p.i, while in other organs, including the brain, no accumulation of (99m)Tc-Elafin was detected. At this time point 30% of the detected radioactivity in the kidney was identified to be not metabolized (99m)Tc-Elafin. In conclusion, the blood and organ-specific kinetic data provide a basis for planning of adequate dosing regimens and the high accumulation of intact elafin in the kidney favors clinical developments targeting inflammatory kidney diseases, such as chronic allograft nephropathy after kidney transplantation. PMID:26948953

  20. Evaluation of five miniature chromatography systems for determining labeling efficiency of technetium Tc 99m pentetate.

    PubMed

    Robbins, P J

    1983-04-01

    The reliability and reproducibility of five miniature chromatography systems for the radiochemical purity of 99mTc-labeled technetium Tc 99m pentetate was evaluated. Radiochemical purity of technetium Tc 99m pentetate was determined 15-30 minutes after preparation once a month for nine consecutive months. A reference value was determined by gel filtration or by conventional-length paper chromatography and thin-layer chromatography. Radiochemical purity was determined simultaneously by five miniature chromatography systems. The miniature systems included an in-house system and commercial systems distributed by Ackerman Nuclear, Ashley Innovations, Atomic Products, and Technical Advancement. Each miniature system was tested in duplicate. A follow-up comparison of the Ackerman Nuclear and in-house systems was performed for an additional nine months. Labeling efficiency by the reference method was greater than 97% for all nine months. The miniature systems gave results that were comparable in most months. Very low labeling efficiency occurred with the Ackerman Nuclear system in month 9. The follow-up comparison produced only one unconfirmed result for the Ackerman Nuclear system that would have caused a laboratory to erroneously discard a batch of technetium Tc 99m pentetate. The miniature chromatography systems evaluated generally will give reliable and reproducible results for the radiochemical purity of technetium Tc 99m pentetate for nine months after receipt of the systems. PMID:6342380

  1. Tc17 CD8+ T cells potentiate Th1-mediated autoimmune diabetes in a mouse model.

    PubMed

    Saxena, Amit; Desbois, Sabine; Carrié, Nadège; Lawand, Myriam; Mars, Lennart T; Liblau, Roland S

    2012-09-15

    An increase in IL-17-producing CD8+ T (Tc17) cells has been reported in the peripheral blood of children with recent onset type 1 diabetes (T1D), but their contribution to disease pathogenesis is still unknown. To directly study the pathogenic potential of β cell-specific Tc17 cells, we used an experimental model of T1D based on the expression of the neo-self Ag hemagglutinin (HA) in the β cells of the pancreas. When transferred alone, the IL-17-producing HA-specific CD8+ T cells homed to the pancreatic lymph nodes without causing any pancreatic infiltration or tissue destruction. When transferred together with small numbers of diabetogenic HA-specific CD4+ T cells, a strikingly different phenotype developed. Under these conditions, Tc17 cells sustained disease progression, driving the destruction of β-islet cells, causing hyperglycemia and ultimately death. Disease progression did not correlate with functional or numerical alterations among the HA-specific CD4+ T cells. Rather, the transferred CD8+ T cells accumulated in the pancreatic islets and a considerable fraction converted, under the control of IL-12, to an IFN-γ-producing phenotype. Our data indicate that Tc17 cells are not diabetogenic but can potentiate a Th1-mediated disease. Plasticity of the Tc17 lineage is associated with transition to overt disease in this experimental model of T1D. PMID:22904307

  2. Technetium-99m galactosyl-neoglycoalbumin (Tc-NGA) liver imaging: Application in liver transplantation

    SciTech Connect

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

    1985-05-01

    Tc-NGA is a new liver imaging agent which binds to hepatic binding protein (HBP), a hepatocyte-specific membrane receptor. The purpose of the present study was to evaluate the potential role of Tc-NGA imaging in liver transplantation. The molar Tc-NGA dose was standardized according to patient weight (0.7 nmole/kg). After a 30 minute dynamic imaging study (5 mCi, IV), kinetic analysis of time activity data (heart, liver), provided values for receptor concentration, (HBP), and hepatic blood flow, Q. Eleven Tc-NGA imaging studies were performed in transplant candidates and 22 studies were performed in seven transplant recipients. Preservation damage was manifested by diffuse patchiness in tracer distribution which resolved during the following two weeks. Histologically proven, localized hepatic infarcts were demonstrated in three recipients. Lobar infarction was demonstrated in one recipient. Hepatic regeneration was later demonstrated in this patient after hepatic lobectomy. Hepatic blood flow was markedly decreased in the early postoperative period, but improved with time. Increased (HBP) was demonstrated with regeneration. Markedly decreased (HBP) and Q were obtained in several candidates who died awaiting transplantation. These studies indicate that TC-NGA liver imaging provides a valuable new means for: (1) evaluation of preservation damage, (2) early demonstration of hepatic infarction, (3) evaluation of hepatic rejection, and (4) selection of patients for hepatic transplantation.

  3. 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

  4. [The study on the in-vitro stability of Tc(V)-99m dimercaptosuccinic acid].

    PubMed

    Lee, B F; Chung, K L; Jong, S B; Yang, C C; Chen, C L; Chen, Y J; Chen, S L; Yu, H S; Ting, G; Shen, L H

    1996-09-01

    Tc(V)-99m DMS, developed by Yokoyama et al. in 1981, has been recognized to be advantageous for the scintigraphic diagnosis of various malignant tumors and their metastasis, the aim of this study is to assess the in-vitro stability of Tc(V)-99m DMS. Thin-layer chromatography, including paper chromatography and silica gel thin layer chromatography, is performed to determine the change of radiochemical species presented in the reconstituted solution of Tc(V)-99m DMS prepared from the DMS kit (Institute of Nuclear Energy Research, Atomic Energy Council R.O.C.) and the commercial DMSA kit (Nephroscint, IRE CELLTARG Radiopharmaceuticals Japan). The bioscan imaging scanner is used to measure the Rf value and labeling efficiency of radiochemical species on the chromatographic strip. The in-vitro stability of Tc(V)-99m DMS prepared from the DMS kit and the commercial DMSA kit is studied by examining various parameters which include temperature(degree C) and time(hr) after reconstitution. The results show that the in-vitro stability of Tc(V)-99m DMS prepared from the DMS kit is actually better than that from the commercial DMSA kit. The one-step labeling method of DMS kit is much simpler than the two-step labeling method of DMSA kit. PMID:8819352

  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. Tumor targeting with a (99m)Tc-labeled AS1411 aptamer in prostate tumor cells.

    PubMed

    Noaparast, Zohreh; Hosseinimehr, Seyed Jalal; Piramoon, Majid; Abedi, Seyed Mohammad

    2015-01-01

    AS1411, a 26-base guanine-rich oligonucleotide aptamer, has high affinity to nucleolin, mainly on tumor cell surfaces. In this study, a modified AS1411 was labeled with (99m)Tc and evaluated as a potential tumor-targeting agent for imaging. The AS1411 aptamer was conjugated with HYNIC and labeled with (99m)Tc in the presence a co-ligand. Radiochemical purity and stability testing of the (99m)Tc-HYNIC-AS1411 aptamer were carried out with thin layer chromatography and a size-exclusion column in normal saline and human serum. Cellular nucleolin-specific binding, cellular internalization in DU-145 cells, as high levels of nucleolin expression, were performed. Additionally, biodistribution in normal mice and DU-145 tumour-bearing mice was assessed. Radiolabeling of the aptamer resulted in a reasonable yield and radiochemical purity after purification. The aptamer was stable in normal saline and human serum, and cellular experiments demonstrated specific binding of the AS1411 aptamer to the nucleolin protein. Based on biodistribution assessment of (99m)Tc-HYNIC-AS1411, rapid blood clearance was seen after injection and it appears that the excretion route was via the urinary system at 1 h post-injection. Tumours also showed a higher accumulation of radioactivity with this labeled aptamer. (99m)Tc-AS1411 can be a potential tool for the molecular imaging of nucleolin-overexpressing cancers. PMID:25673264

  7. TGF-β and IL-21 cooperatively stimulate activated CD8(+) T cells to differentiate into Tc17 cells.

    PubMed

    Chen, Hsin-Wei; Tsai, Jy-Ping; Yao, Tsung-You; Hsieh, Chia-Ling; Chen, I-Hua; Liu, Shin-Jen

    2016-06-01

    TGF-β together with IL-21 or IL-6 can drive the differentiation of naïve CD8(+) T cells into IL-17-producing CD8(+) T cells. These IL-17-producing CD8(+) T cells are termed Tc17 cells. Tc17 cells preserve plasticity under various conditions in vitro and in vivo. IFN-γ-producing CD8(+) T cells are termed Tc1 cells. However, Tc1 cells are considered relatively stable. In the present study, we show that the combination of TGF-β plus IL-21, but not IL-6, converts Tc1 cells into Tc17 cells; this conversion is associated with elevated RORα, RORγt, and Batf mRNA levels. These results indicate that Tc1 cells are skewed to the Tc17 cell phenotype under TGF-β plus IL-21-polarizing conditions. Furthermore, IL-6R is expressed on naïve, but not activated, CD8(+) T cells. In contrast, IL-21R is expressed on both naïve and activated CD8(+) T cells. Thus, differential expression profiles of IL-6R and IL-21R on naïve and activated CD8(+) T cells may be one mechanism by which TGF-β plus IL-21, but not IL-6, can drive activated CD8(+) T cells to differentiate into IL-17-producing cells. Taken together, these results provide a novel viewpoint for the plasticity of Tc1 cells. PMID:27085379

  8. Tc1 mouse model of trisomy-21 dissociates properties of short- and long-term recognition memory

    PubMed Central

    Hall, Jessica H.; Wiseman, Frances K.; Fisher, Elizabeth M.C.; Tybulewicz, Victor L.J.; Harwood, John L.; Good, Mark A.

    2016-01-01

    The present study examined memory function in Tc1 mice, a transchromosomic model of Down syndrome (DS). Tc1 mice demonstrated an unusual delay-dependent deficit in recognition memory. More specifically, Tc1 mice showed intact immediate (30 sec), impaired short-term (10-min) and intact long-term (24-h) memory for objects. A similar pattern was observed for olfactory stimuli, confirming the generality of the pattern across sensory modalities. The specificity of the behavioural deficits in Tc1 mice was confirmed using APP overexpressing mice that showed the opposite pattern of object memory deficits. In contrast to object memory, Tc1 mice showed no deficit in either immediate or long-term memory for object-in-place information. Similarly, Tc1 mice showed no deficit in short-term memory for object-location information. The latter result indicates that Tc1 mice were able to detect and react to spatial novelty at the same delay interval that was sensitive to an object novelty recognition impairment. These results demonstrate (1) that novelty detection per se and (2) the encoding of visuo-spatial information was not disrupted in adult Tc1 mice. The authors conclude that the task specific nature of the shortterm recognition memory deficit suggests that the trisomy of genes on human chromosome 21 in Tc1 mice impacts on (perirhinal) cortical systems supporting short-term object and olfactory recognition memory. PMID:26868479

  9. Size Control of (99m)Tc-tin Colloid Using PVP and Buffer Solution for Sentinel Lymph Node Detection.

    PubMed

    Kim, Eun-Mi; Lim, Seok Tae; Sohn, Myung-Hee; Jeong, Hwan-Jeong

    2015-06-01

    Colloidal particle size is an important characteristic that allows mapping sentinel nodes in lymphoscintigraphy. This investigation aimed to introduce different ways of making a (99m)Tc-tin colloid with a size of tens of nanometers. All agents, tin fluoride, sodium fluoride, poloxamer-188, and polyvinylpyrrolidone (PVP), were mixed and labeled with (99m)Tc. Either phosphate or sodium bicarbonate buffers were used to adjust the pH levels. When the buffers were added, the size of the colloids increased. However, as the PVP continued to increase, the size of the colloids was controlled to within tens of nanometers. In all samples, phosphate buffer added PVP (30 mg) stabilized tin colloid ((99m)Tc-PPTC-30) and sodium bicarbonate solution added PVP (50 mg) stabilized tin colloid ((99m)Tc-BPTC-50) were chosen for in vitro and in vivo studies. (99m)Tc-BPTC-50 (<20 nm) was primarily located in bone marrow and was then secreted through the kidneys, and (99m)Tc-PPTC-30 (>100 nm) mainly accumulated in the liver. When a rabbit was given a toe injection, the node uptake of (99m)Tc-PPTC-30 decreased over time, while (99m)Tc-BPTC-50 increased. Therefore, (99m)Tc-BPTC-50 could be a good candidate radiopharmaceutical for sentinel node detection. The significance of this study is that nano-sized tin colloid can be made very easily and quickly by PVP. PMID:26028937

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

    SciTech Connect

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

    1980-07-01

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

  11. Systematic evaluation of 99mTc-tetrofosmin versus 99mTc-sestamibi to study murine myocardial perfusion in small animal SPECT/CT

    PubMed Central

    2012-01-01

    Background The “back-translation” of clinically available protocols to measure myocardial perfusion to preclinical imaging in mouse models of human disease is attractive for basic biomedical research. With respect to single-photon emission computed tomography (SPECT) approaches, clinical myocardial perfusion imaging protocols are established with different 99mTc-labeled perfusion tracers; however, studies evaluating and optimizing protocols for these tracers in high-resolution pinhole SPECT in mice are lacking. This study aims at evaluating two clinically available 99mTc-labeled myocardial perfusion tracers (99mTc-sestamibi vs. 99mTc-Tetrofosmin) in mice using four different imaging protocols. Methods Adult C57BL/6 male mice were injected with 99mTc-sestamibi (MIBI) or 99mTc-Tetrofosmin (TETRO) (4 MBq/g body weight) either intravenously through the tail vein (n = 5) or retroorbitally (n = 5) or intraperitoneally (i.p.) under anesthesia (n = 3) or i.p. in an awake state (n = 3) at rest. Immediately after injection, a multi-frame single-photon emission computed tomography/computed tomography (SPECT/CT) acquisition was initiated with six subsequent time frames of 10 min each. Reconstructed images of the different protocols were assessed and compared by visual analysis by experts and by time-activity-curves generated from regions-of-interest for various organs (normalized uptake values). Results Visually assessing overall image quality, the best image quality was found for MIBI for both intravenous injection protocols, whereas TETRO only had comparable image quality after retroorbital injections. These results were confirmed by quantitative analysis where left ventricular (LV) uptake of MIBI after tail vein injections was found significantly higher for all time points accompanied with a significantly slower washout of 16% for MIBI vs. 33% for TETRO (p = 0.009) from 10 to 60 min post injection (PI). Interestingly, LV washout from 10 to 60 min PI

  12. Thermodynamic Model for the Solubility of TcO2•xH2O(am) in the Aqueous Tc(IV) - Na+ - Cl- - H+ - OH- - H2O System

    SciTech Connect

    Hess, Nancy J.; Xia, Yuanxian; Rai, Dhanpat; Conradson, Steven D.

    2004-02-01

    Solubility studies of TcO2•xH2O(am) have been conducted as a function of H+ concentration from 1 x 10-5 to 6 M HCl and as function of chloride concentration from 1 x 10-3 to 5 M NaCl. These experiments were conducted under carefully controlled reducing conditions such that the preponderance of Tc is present in solution is in the reduced oxidation state and was determined to be Tc(IV) by XANES analysis. The aqueous species and solid phases were characterized using a combination of techniques including thermodynamic analyses of solubility data, XRD, and XANES, EXAFS, and UV-Vis spectroscopies. Chloride was found to significantly affect Tc(IV) concentrations through 1) the formation of Tc(IV) chloro complexes [i.e., TcCl4(aq) and TcCl62-] and a stable compound [data suggests this compound to be TcCl4(am)] in highly acidic and relatively concentrated chloride solutions, and 2) its interactions with the positively charged hydrolyzed Tc(IV) species in solutions of relatively low acidity and high chloride concentrations. A thermodynamic model was developed, which included hitherto unavailable chemical potentials of Tc(IV)-chloro species and Pitzer ion-interaction parameters for Tc(IV) hydrolyzed species with bulk electrolyte ions used in this study. The thermodynamic model presented in this paper is consistent with the extensive data reported in this study and with the reliable literature data, and is applicable to a wide range in H+ and Cl- concentrations and ionic strengths.

  13. Synthesis and characterization of novel N3O3-Schiff base complexes of 99gTc, and in vivo imaging studies with analogous 99mTc complexes.

    PubMed

    Marmion, M E; Woulfe, S R; Newmann, W L; Pilcher, G; Nosco, D L

    1996-07-01

    Sixteen novel derivatives of 1,1,1-tris (salicylaldiminomethyl)ethane have been synthesized for the purpose of encapsulating 99mTc(IV) ions and generating new 99mTc radiopharmaceuticals. Two methods for the preparation of the 99gTc(IV) analog complexes are presented; one utilizes SnCl2 reduction on 99gTcO4- and the other a direct substitution route starting with [99gTcCl6]2-. Free ligands (H3L) are characterized by melting points, 1H NMR, 13C NMR, mass spectroscopy, TLC, and/or elemental analyses. [99gTcL]+ complexes are characterized by FAB-ms, UV-VIS, IR and/or CV. An X-ray structural analysis was performed on a crystal of [M(6,6'-[[2-[[((4-Methoxy-2-hydroxyphenyl) methylene)-amino]methyl]-2-methyl- 1,3-propanediyl]bis(nitrilomethylidyne)]-bis-3-methoxyphenol )] tetraphenylborate, where M represents a 1/3 isomorphous mixture of 99gTc/Sn as determined by SEM. The metal coordination site is 6-coordinate, composed of N3O3 donor atoms, and intermediate between octahedral and trigonal prismatic geometry. The [99mTcL]+ complexes were prepared in a stannous environment; equivalence of the 99mTc and 99gTc complexes is demonstrated by HPLC techniques. The [SnL]+ complex was prepared for comparison purposes. An unusual ligand oxidation occurs for one series of ligands in which in situ amine-->imine conversion is observed during the complexation reaction in reducing media. Guinea pig, rat, dog, and human metabolism studies are reported for selected [99mTcL]+ complexes, the myocardial uptake of which approaches 2% of the injected dose. PMID:8905821

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

    NASA Astrophysics Data System (ADS)

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

    2007-03-01

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

  15. Debye temperature, thermal expansion, and heat capacity of TcC up to 100 GPa

    SciTech Connect

    Song, T.; Ma, Q.; Tian, J.H.; Liu, X.B.; Ouyang, Y.H.; Zhang, C.L.; Su, W.F.

    2015-01-15

    Highlights: • A number of thermodynamic properties of rocksalt TcC are investigated for the first time. • The quasi-harmonic Debye model is applied to take into account the thermal effect. • The pressure and temperature up to about 100 GPa and 3000 K, respectively. - Abstract: Debye temperature, thermal expansion coefficient, and heat capacity of ideal stoichiometric TcC in the rocksalt structure have been studied systematically by using ab initio plane-wave pseudopotential density functional theory method within the generalized gradient approximation. Through the quasi-harmonic Debye model, in which the phononic effects are considered, the dependences of Debye temperature, thermal expansion coefficient, constant-volume heat capacity, and constant-pressure heat capacity on pressure and temperature are successfully predicted. All the thermodynamic properties of TcC with rocksalt phase have been predicted in the entire temperature range from 300 to 3000 K and pressure up to 100 GPa.

  16. 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

  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. X-ray diffuse scattering experiments on bismuth based high Tc superconductors

    NASA Astrophysics Data System (ADS)

    Comes, R.; Izquierdo, M.; Megtert, S.; Albouy, P. A.; Avila, J.; Valbuena, M. A.; Gu, G.; Abell, J. S.; Asensio, M. C.

    2007-09-01

    A detailed X-ray diffuse scattering study of the recently found two dimensional (2D) displacive short range order (SRO) superstructure, with doubled periodicity along the orthorhombic a direction from the high Tc superconductors Bi 2Sr 2CaCu 2O 8+ δ (BISCO-2212) is reported. The investigation has been extended to high and low temperatures for optimally doped crystals, to crystals with different doping levels and to the one layer compound Bi 2Sr 2CuO 6+ δ (BISCO-2201). The most striking feature is that both, the intensity of the diffuse scattering and the extent of the 2DSRO vary with doping as the critical temperature, Tc. These findings show that these short range ordering features are of importance for a better understanding of high Tc materials, at least those from the BISCO family.

  19. Emergence of superconductivity in HighTc copper oxide superconductors via two crossovers

    NASA Astrophysics Data System (ADS)

    Chatterjee, Utpal; Norman, Mike; Randeria, Mohit; Rosenkranz, Stephan; Campuzano, Juan Carlos

    2011-03-01

    From our detailed ARPES measurements on BISCO 2212 High Tc Superconductors we found that unlike in conventional superconductors, where there is a single temperature scale Tc separating the normal from the superconducting state, HTSCs exhibit with two additional temperature scales. One is T*, below which electronic excitations are gapped. And the other one is Tcoh, below which electronic states are long-lived. We observed that T* and Tcoh change strongly with doping. They cross each other near optimal doping. There is a region in the normal state where the single particle excitations are gapped as well as coherent. Quite remarkably, this is the region from which superconductivity with highest Tc emerges. Our experimental finding that the two crossover lines intersect is not consistent with a ``single quantum critical'' point near optimal doping, rather it is more naturally consistent with theories of superconductivity for doped Mott insulators.

  20. X-ray diffuse scattering experiments from bismuth based high Tc superconductors

    NASA Astrophysics Data System (ADS)

    Izquierdo, M.; Megtert, S.; Albouy, P. A.; Avila, J.; Valbuena, M. A.; Gu, G.; Abell, J. S.; Yang, G.; Asensio, M. C.; Comes, R.

    2007-03-01

    A detailed X-ray diffuse scattering study of the recently found two dimensional (2D) displacive short range order (SRO) superstructure, with doubled periodicity along the orthorhombic a direction from the high Tc superconductors Bi2Sr2CaCu2O8+δ(BISCO-2212) is reported. The investigation has been extended to high and low temperatures for optimally doped crystals, to crystals with different doping levels and to the one layer compound Bi2Sr2CaCuO6+δ (Bi-2201). The most striking feature is that both, the intensity of the diffuse scattering and the extent of the 2DSRO vary with doping as the critical temperature, Tc. These findings show that these short range ordering features are of importance for a better understanding of high Tc materials, at least those from the BISCO family.

  1. SPECT measurements with /sup 99m/Tc-HM-PAO in focal epilepsy

    SciTech Connect

    Ryding, E.; Rosen, I.; Elmqvist, D.; Ingvar, D.H.

    1988-12-01

    The ability of SPECT measurements with (/sup 99m/Tc)-HM-PAO (Ceretec) to find the location of the epileptic focus was studied in patients under consideration for neurosurgical treatment for therapy-resistant focal epilepsy. The location of low (/sup 99m/Tc)-HM-PAO uptake regions found at interictal measurements, and of high (/sup 99m/Tc)-HM-PAO uptake regions found at ictal measurements, was compared to the findings of extensive ictal and interictal EEG examinations, and to the results of CT and MRT. While EEG revealed focal epileptic activity in all of the 14 patients, SPECT showed regional abnormalities in 13 (93%). CT and MRT showed abnormal findings in 30%.

  2. NMR investigation of iron-selenide and iron-arsenide high Tc superconductors

    NASA Astrophysics Data System (ADS)

    Imai, Takashi

    2012-02-01

    We have investigated the electronic, magnetic, and superconducting properties of the iron-selenide high Tc superconductor KxFe2-ySez (Tc=33 K) with ^77Se NMR [1]. We will compare the results with those observed for FeSe in ambient and applied pressures (Tc>9 K) [2], and with iron-arsenides [3]. Similarities and dissimilarities will be pointed out, with primary focus on the anomalous normal state properties. Our latest work on KxFe2-ySez was carried out in collaboration with D. Torchetti, M. Fu, D. Christensen, K. Nelson (McMaster), H. Lei, and C. Petrovic (Brookhaven National Lab).[4pt] [1] D. Torchetti et al., PR B83, 104508 (2011).[0pt] [2] T. Imai et al. PRL 102, 177005 (2009).[0pt] [3] F.L. Ning et al., PRL 104, 037001 (2010); JPSJ 78, 103711 (2009).

  3. Search for high-Tc conventional superconductivity at megabar pressures in the lithium-sulfur system

    NASA Astrophysics Data System (ADS)

    Kokail, Christian; Heil, Christoph; Boeri, Lilia

    2016-08-01

    Motivated by the recent report of superconductivity above 200 K in ultra-dense hydrogen sulfide, we search for high-TC conventional superconductivity in the phase diagram of the binary Li-S system, using ab initio methods for crystal structure prediction and linear response calculations for the electron-phonon coupling. We find that at pressures higher than 20 GPa, several new compositions, besides the known Li2S , are stabilized; many exhibit electride-like interstitial charge localization observed in other alkali-metal compounds. Of all predicted phases, only an fcc phase of Li3S , metastable before 640 GPa, exhibits a sizable TC, in contrast to what is observed in sulfur and phosphorus hydrides, where several stoichiometries lead to high TC. We attribute this difference to 2 s -2 p hybridization and avoided core overlap, and predict similar behavior for other alkali-metal compounds.

  4. Circulation of Tc Ia discrete type unit Trypanosoma cruzi in Yucatan Mexico.

    PubMed

    Monteón, Victor; Triana-Chávez, Omar; Mejía-Jaramillo, Ana; Pennignton, Pamela; Ramos-Ligonio, Ángel; Acosta, Karla; Lopez, Ruth

    2016-06-01

    The etiologic agent Trypanosoma cruzi (Tc) has been grouped into six discrete type units (DTU I-VI); within DTU-I exists four subgroups defined Ia-Id. In Colombia, the genotype Ia is associated with human infection and domiciliated Rhodnius vector. In the Yucatan Peninsula of Mexico, the main vector involved in T. cruzi transmission is Triatoma dimidiata predominantly via sylvatic and peridomiciliated cycles. In this study, multiple sequence analysis of mini-exon intergenic regions of T. cruzi isolates obtained from T. dimidiata in the Yucatan Peninsula of Mexico revealed they belonged to Tc Ia DTU along with two additional Mexican strains located 1,570 km away from Yucatan. In conclusion Tc Ia circulates in the Yucatan peninsula in T. dimidiata vector and likewise in the northwest region of Mexico. PMID:27413339

  5. Tc-99m galactosyl-neoglycoalbumin: in vitro characterization of receptor-mediated binding

    SciTech Connect

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

    1984-07-01

    Hepatic binding protein (HBP) is a membrane receptor that binds and transports plasma glycoproteins from hepatic blood to hepatocellular lysosomes. The authors have characterized the in vitro binding of Tc-99m galactosyl-neoglycoalbumin (Tc-NGA), a synthetic HBP ligand, to liver membrane. Membrane displacement studies, using carrier ligands in contrast to previously bound Tc-NGA or I-NGA, correlated with the binding characteristics of a native HBP ligand, asialo-orosomucoid. They used computer simulation to study the detectibility of the changes in HBP concentration at different values of k/sub b/. The simulations indicated that radiopharmacokinetic sensitivity to alterations in (HBP) should be possible using a neoglycoalbumin preparation with a carbohydrate density within the range of 15 to 25 galactose units per albumin molecule.

  6. Abdominal and hepatic uptake of /sup 99m/Tc-pyrophosphate in neonatal necrotizing enterocolitis

    SciTech Connect

    Caride, V.J.; Touloukian, R.J.; Ablow, R.C.; Lange, R.C.; Matthews, T.

    1981-04-01

    Abdominal /sup 99m/Tc-pyrophosphate (/sup 99m/Tc-PYP) scans were obtained in 15 neonates: 12 with neonatal necrotizing enterocolitis (NEC), two with osteomyelitis, and one with myocarditis. Ten of the babies with NEC had at least one positive scan; of these 10 studies, seven (Group A) showed both diffuse abdominal uptake and localized hepatic activity, two (Group B) showed abdominal uptake and questionable hepatic uptake, and one (Group C) demonstrated diffuse abdominal uptake only. The other two babies with NEC had normal scans (Group D). All NEC patients had normal scans. A patient with myocarditis had hepatic uptake of /sup 99m/Tc-PYP while the abdominal scan in the two infants with osteomyelitis was normal. These preliminary observations suggest that further study of a relationship between abdominal scan findings and the course of NEC is warranted.

  7. 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, β(-) 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, α(1)-P(2)W(17)O(61)(10-) (α1) and α(2)-P(2)W(17)O(61)(10-) (α2) 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(α(1)-P(2)W(17)O(61))] (Tc(V)O-α1), K(7-n)H(n)[Tc(V)O(α(2)-P(2)W(17)O(61))] (Tc(V)O-α2) 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 α1 site as compared to the α2 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-α1 are not pH dependent or only slightly pH dependent suggesting that protonation does not accompany reduction of this species unlike the M(V)O-α2 (M = (99)Tc, Re) and Re(V)O-α1 where M(V/IV) reduction process must occur hand in hand with protonation of the terminal M═O to

  8. Imaging human atherosclerosis with /sup 99m/Tc-labeled low density lipoproteins

    SciTech Connect

    Lees, A.M.; Lees, R.S.; Schoen, F.J.; Isaacsohn, J.L.; Fischman, A.J.; McKusick, K.A.; Strauss, H.W.

    1988-09-01

    The feasibility of localizing human atherosclerotic plaques by gamma scintillation camera external imaging with technetium-99m-labeled low density lipoproteins (99mTc-LDL) was tested in 17 patients who had atherosclerosis. Imaging demonstrated focal accumulation of radiolabel consistent with 99mTc-LDL sequestration by plaques in the carotid, iliac, or femoral vessels of four patients 8 to 21 hours after intravenous injection of the radiopharmaceutical. Focal accumulation of 99mTc-LDL also appeared in the location of coronary lesions in four patients, but this accumulation could not be distinguished with certainty from residual blood pool radioactivity. When carotid endarterectomy specimens from six patients who received 99mTc-LDL 1 day before endarterectomy were examined, the specimens had focal accumulations of radiolabel, with two to four times greater radioactivity in some regions of each specimen than in others; this occurred whether or not the lesions were detected on the gamma camera images. Lesion composition may have determined whether accumulation was quantitatively sufficient to produce an external image. Histologically, the imaged carotid specimen had abundant foam cells and macrophages and poorly organized intramural blood consistent with a plaque hemorrhage; in contrast, nonimaged endarterectomy specimens were mature, fibrocalcific plaques. We conclude that: 1) 99mTc-LDL did accumulate in human atherosclerotic plaques; 2) in some patients, the accumulation of 99mTc-LDL was sufficient for detection by gamma camera imaging; 3) the amount of LDL that accumulated appeared to depend on lesion composition; and 4) the design of new radiopharmaceuticals with reduced residual blood pool activity relative to plaque accumulation should lead to improved external imaging of atherosclerosis.

  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. Permeability of the bronchial mucosa to /sup 99m/Tc-DTPA in asthma

    SciTech Connect

    Ilowite, J.S.; Bennett, W.D.; Sheetz, M.S.; Groth, M.L.; Nierman, D.M.

    1989-05-01

    Previous investigators, using 99mTc-DTPA aerosol as a marker to assess epithelial permeability in asthma, did not find an increased permeability in this group. However, they either failed to deliver the aerosol to the optimal site (bronchial mucosa, not alveoli) or failed to account for mucociliary clearance in analyzing their results. We studied 10 asthmatics and eight age-matched control subjects using a dosimeter (Spira-Elektra 2) and a carefully controlled breathing pattern to deliver aerosol to the subjects' airways. Two aerosols were delivered on separate days in each patient; 99mTc-DTPA aerosol, and 99mTc-HSA (human serum albumin), using similar breathing patterns to ensure reproducibility of the deposition pattern with the two aerosols. From measurements of retention versus time over a 1-h period, rate constants Ktot and Km were determined for the clearance of 99mTc-DTPA and 99mTc-HSA, respectively. By modelling the airways as a single compartment with two possible routes of clearance, we determined the permeability rate constant, Kp, as Ktot minus Km. There was no significant difference between Ktot in normal subjects and asthmatics; however, because of the slower mucociliary clearance in the asthmatic group, and the relative importance of mucociliary clearance in determining the washout of 99mTc-DTPA aerosol, there was a significant difference in airway permeability between the normal subjects and the asthmatics (t1/2 = 296 min +/- 141 SD and 126 min +/- 58, p less than 0.01, in normal subjects and asthmatics, respectively).

  11. CGRP 4218T/C polymorphism correlated with postoperative analgesic effect of fentanyl

    PubMed Central

    Yi, Yusheng; Zhao, Mingqiang; Xu, Fenghe; Liu, Chuansheng; Yin, Yanwei; Yu, Junmin

    2015-01-01

    Purpose: Our study aimed at evaluating the association between α-calcitonin gene-related peptide (CGRP) 4218T/C polymorphism and the patient-controlled analgesic (PCA) effect of fentanyl on Chinese Han population. Methods: 98 patients were involved in the experiment, but only 92 patients completed the experiment. 0.1 mg/kg fentanyl was given to the patients through intravenous injection ten minutes before the ending of surgery. The patients achieved PCA by controlling the fentanyl infusion pump and a single dose was 1 mg. The CGRP 4218T/C polymorphism was genotyped with polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) method. The fentanyl consumption within the 72 hours after the surgery was recorded and the pain was assessed with numeric rating scale (NRS) method. Results: The patients were divided into three groups of wild homozygote (T/T), heterozygote (T/C), and mutant homozygote (C/C). At the 6th hour and the 12th hour after the surgery, the fentanyl consumption for PCA of the T/C group was significantly higher than the T/T group (P<0.05). Meanwhile, the fentanyl consumption of the C/C group was much higher than the T/T group (P<0.05) at the 12th hour and the 24th hour. Besides, the fentanyl consumption of the C/C group was more than the T/C group (P<0.05) at the 24th hour. The differences in NRS scores, Ramsey scores, and postoperative adverse reactions between each group at all time points were not statistically significant. Conclusions: CGRP 4218T/C polymorphism may be associated with the postoperative fentanyl consumption for analgesia. PMID:26191294

  12. 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 γ-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

  13. A Very High-Cycle Fatigue Test and Fatigue Properties of TC17 Titanium Alloy

    NASA Astrophysics Data System (ADS)

    Jiao, Shengbo; Gao, Chao; Cheng, Li; Li, Xiaowei; Feng, Yu

    2016-03-01

    The present work studied the very high-cycle fatigue (VHCF) test and fatigue properties of TC17 titanium alloy. The specimens for bending vibration were designed using the finite element method and the VHCF tests were conducted by using the ultrasonic fatigue testing system. The results indicated that there is no the fatigue limit for TC17 titanium alloy, and the S-N curve shows a continuously descending trend. The fatigue crack initiates at the specimen surface within the range of VHCF and the VHCF lives follow the log-normal distribution more closely.

  14. Unusual Tc-99m MDP and I-123 MIBG images in focal pyelonephritis

    SciTech Connect

    Jacobs, A.; Lenoir, P.; Delree, M.; Ramet, J.; Piepsz, A. )

    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.

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

    SciTech Connect

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

    1985-01-01

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

  16. Ectopic Intrathymic Parathyroid adenoma demonstrated on Tc-99m Sestamibi SPECT-CT.

    PubMed

    Usmani, S; Oteifa, M; Abu Huda, F; Javaid, A; Amanguno, H G; Al Kandari, F

    2016-05-01

    Intrathymic parathyroid adenoma is a rare cause of primary hyperparathyroidism. In this case, Tc-99m Sestamibi SPECT-CT successfully localized abnormal tracer uptake in the mediastinum with corresponding low density lesion on CT images suggestive of mediastinal parathyroid adenoma which late on confirmed on histopathology. After the median sternotomy a large intrathymic parathyroid adenoma was identified and excised. With the help of gamma probe the surgeons detect the lesion early and with more confidence as well as reducing the total operation time. Tc-99m Sestamibi SPECT-CT scintigraphy and gamma probe localization is recommended for preoperative and intra operative localization of ectopic parathyroid adenomas. PMID:27250890

  17. 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.

  18. Neurofibromas: location by scanning with Tc-99m DTPA. Work in progress

    SciTech Connect

    Mandell, G.A.; Herrick, W.C.; Harcke, H.T.; Sharkey, C.; Brooks, K.M.; MacEwen, G.D.

    1985-12-01

    The accumulation of technetium-99m diethylenetriamine pentaacetic acid (Tc-99m DTPA) in benign soft-tissue neurofibromatosis tumors is reported. In a series of 16 patients with clinical stigmata of neurofibromatosis, 28 sites of abnormal soft-tissue localization of the isotope observed scintigraphically were documented to be sites of soft-tissue tumor by clinical and/or radiographic (predominantly computed tomographic) correlations. The smallest lesion detected was a 1.5-cm subcutaneous neurofibroma. Normal physiologic nonrenal distribution of the Tc-99m DTPA was established by scintigraphic imaging of a control population.

  19. Failure to diagnose cardiac treatment rejection with Tc99m-PYP images

    SciTech Connect

    McKillop, J.H.; McDougall, I.R.; Goris, M.L.; Mason, J.W.; Reitz, B.A.

    1981-08-01

    The possibility of diagnosing transplant rejection using Tc-99m-PYP imaging was examined in 12 cardiac transplant recipients. Two patients were studied on two occasions. The presence or absence of active rejection was established by endomyocardial biopsy. The intensity and pattern of myocardial uptake of the tracer did not differ significantly in the two patients studied at the time of rejection compared to the remainder. It is concluded that a single Tc-99m-PYP study cannot be used to diagnose cardiac transplant rejection.

  20. Tc-99m-galactosyl-neoglycoalbumin: in vivo characterization of receptor-mediated binding to hepatocyctes

    SciTech Connect

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

    1984-04-01

    The biodistribution and kinetics of a receptor-binding hepatic radiopharmaceutical, Tc-99m-galactosyl-neoglycoalbumin (Tc-NGA), were investigated using mammalian and avian models. The radiopharmaceutical exhibited four significant features associated with receptor-mediated binding at the hepatocyte membrane in mammals: (a) high tissue specificity, (b) high molecular specificity, (c) affinity-dependent uptake, and (d) dose-dependent uptake. Diminished hepatic uptake by the avian model illustrated low nonspecific binding. The kinetic sensitivity to ligand-receptor affinity and stoichiometry illustrated the principal feature of receptor-binding radiopharmaceuticals, namely, quantitative assessment of tissue function based upon the biochemical interaction of a ligand and its specific receptor.

  1. 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.

  2. [Imaging of hyperparathyroidism-Ultrasonography and 99mTc-MIBI scintigraphy-].

    PubMed

    Kawabe, Joji; Higashiyama, Shigeaki; Yoshida, Atsushi; Kotani, Kohei; Shiomi, Susumu

    2016-06-01

    Treatments for primary hyperparathyroidism due to adenoma, hyperplasia and carcinoma and secondary hyperparathyroidism are mainly surgical resections of them. Accurate imaging diagnoses of the existences and the regions are very important for reductions of invasiveness. We describe ultrasonography and 99mTc-MIBI scintigraphy of hyperparathyroidism. We explain an advantage, a disadvantage and diagnosability of these modalities. We mention utilities of SPECT/CT, too. We show echogram and 99mTc-MIBI scintigraphy images about 3 cases of hyperparathyroidism. PMID:27230842

  3. First-principles prediction of the equation of state for TcC with rocksalt structure

    NASA Astrophysics Data System (ADS)

    Sun, Xiao-Wei; Chu, Yan-Dong; Liu, Zi-Jiang; Song, Ting; Tian, Jun-Hong; Wei, Xiao-Ping

    2014-10-01

    The equation of state of TcC with rocksalt structure is investigated by means of first-principles density functional theory calculations combined with the quasi-harmonic Debye model in which the phononic effects are considered. Particular attention is paid to the predictions of the compressibility, the isothermal bulk modulus and its first pressure derivative which play a central role in the formulation of approximate equations of state for the first time. The properties of TcC with rocksalt structure are summarized in the pressure range of 0-80 GPa and the temperature up to 2500 K.

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

    SciTech Connect

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

    1993-11-01

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

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

    SciTech Connect

    Sugiura, Toshihiko; Fujimori, Hideki

    1996-05-01

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

  6. Magnetic field generated by shielding current in high Tc superconducting coils for NMR magnets

    NASA Astrophysics Data System (ADS)

    Amemiya, Naoyuki; Akachi, Ken

    2008-09-01

    Numerical electromagnetic field analyses of high Tc superconducting tape in coils were carried out to calculate the magnetic field generated by the shielding (magnetization) current in superconducting tape. The numerical model employs the power law electric field-current density characteristic and the thin strip approximation, in which the current component normal to the wide face of the tape is neglected. The shielding (magnetization) currents lead to non-uniform current distributions in the superconducting tape in the coils. The magnetic field generated by the shielding (magnetization) current can deteriorate the field quality and could be a concern in insert coils for NMR magnets using high Tc superconducting tape.

  7. Continuous and reversible operation of Bi2212 based THz emitters just below Tc

    NASA Astrophysics Data System (ADS)

    Minami, Hidetoshi; Orita, Naoki; Koike, Takashi; Yamamoto, Takashi; Kadowaki, Kazuo

    2010-12-01

    Continuous and reversible operation of the THz-light emitters comprised of the intrinsic Josephson junction (iJJ) system of high-Tc superconductor BiSrCaCuO (Bi2212) is reported. This reversible emission is observed in samples made of lightly underdoped crystals when a part of the mesa device is so overheated by Joule heating that the temperature reaches Tm near but still below Tc, while the irreversible type of emission occurs at less overheated condition. The large temperature gradient in the mesa due to overheating under high bias currents seems to be responsible for the new observed reversible emission.

  8. Role of Pressure and Magnetic Scattering on the Tc of the Cuprates

    NASA Astrophysics Data System (ADS)

    Wolf, Stuart; Kresin, Vladimir; Ovchinnikov, Yurii

    1996-03-01

    We can show that the large pressure effects on the transition temperature in the superconducting cuprates are caused by an unusual interplay between carrier doping and pair-breaking scattering. This pair-breaking scattering leads to a depression of Tc relative to its intrinsic value which we find to be in the range of 160K. Using these ideas we can explain the relative transition temperature in the one, two, and three layer cuprates as well as estimate the maximum Tc for the cuprate family of superconductors.

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

    NASA Astrophysics Data System (ADS)

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

    2015-03-01

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

  10. Trypanosoma cruzi TcI and TcII transmission among wild carnivores, small mammals and dogs in a conservation unit and surrounding areas, Brazil.

    PubMed

    Rocha, Fabiana Lopes; Roque, André Luiz Rodrigues; Arrais, Ricardo Corassa; Santos, Jean Pierre; Lima, Valdirene dos Santos; Xavier, Samanta Cristina das Chagas; Cordeir-Estrela, Pedro; D'Andrea, Paulo Sérgio; Jansen, Ana Maria

    2013-02-01

    Aiming to better understand the ecological aspects of Trypanosoma cruzi transmission cycles, wild carnivores, small mammals and dogs were examined for T. cruzi infection in the Serra da Canastra National Park region, Brazil. Isolates were genotyped using mini-exon gene and PCR-RFLP (1f8 and H3) genomic targets. Trypanosoma cruzi transmission was well established in the area and occurred in both wild and peridomestic environments. Dog seroprevalence was 29·4% (63/214) and TcI and TcII genotypes, besides mixed infections were observed. Only TcI was detected in wild mammals. Marsupials displayed lower relative abundance, but a high prevalence of positive haemocultures (4/22), whereas rodents displayed positive haemocultures (9/113) mainly in the abundant Akodon montensis and Cerradomys subflavus species. The felid Leopardus pardalis was the only carnivore to display positive haemoculture and was captured in the same region where the small mammal prevalence of T. cruzi infection was high. Two canid species, Chrysocyon brachyurus and Cerdocyon thous, were serologically positive for T. cruzi infection (4/8 and 8/39, respectively), probably related to their capacity to exploit different ecological niches. Herein, dog infection not only signals T. cruzi transmission but also the genotypes present. Distinct transmission strategies of the T. cruzi genotypes are discussed. PMID:23062278

  11. The Study of 99mTc-Aluminum Oxide Using for Sentinel Lymph Nodes Detection in Experiment

    NASA Astrophysics Data System (ADS)

    Medvedeva, A. A.; Sinilkin, I. G.; Zelchan, R. V.; Chernov, V. I.; Lyapunov, A. Yu.; Bragina, O. D.; Varlamova, N. V.; Skuridin, V. S.; Dergilev, A. P.

    2016-06-01

    The purpose of the study was a comparative research of the possibility of using the radiopharmaceuticals 99mTc-Al2O3 and 99mTc-Nanocis for visualizing sentinel lymph nodes in the experiment. Measurement of the sizes of 99mTc-Al2O3 and 99mTc-Nanocis colloidal particles was performed in seven series of radiopharmaceuticals. Pharmacokinetics of 99mTc-Al2O3 and 99mTc-Nanocis was researched on 50 white male rats. The possibility of the use of 99mTc-Al2O3 and 99mTc-Nanocis for lymphoscintigraphy was studied in the experiments on 12 white male rats. Average dynamic diameter of the sol particle was 52-77 nm for 99mTc-Al2O3 and 16.7-24.5 nm for 99mTc-Nanocis. Radiopharmaceuticals accumulated in the inguinal lymph node - at 1 hour after administration the average uptake of 99mTc-Al2O3 was 8.6% in it and the accumulation of 99mTc-Nanocis was significantly lower - 1,8% (p <0,05). In all study point average uptake of 99mTc-Al2O3 in the lymph node was significantly higher 99mTc-Nanocis accumulation. The results dynamic scintigraphic studies in rats showed that 99mTc-Al2O3 and 99mTc-Nanocis actively accumulated into the lymphatic system. By using 99mTc-Al2O3 inguinal lymph node was determined in 5 minutes after injection and clearly visualize in all the animals in the 15th minute, when the accumulation became more than 1% of the administered dose. Further observation indicated that the 99mTc-Al2O3 accumulation reaches a plateau in a lymph node (average 10.5%) for 2 hour study and then its accumulation remains practically at the same level, slightly increasing to 12% at 24 hours. In the case of 99mTc-Nanocis inguinal lymph node visualized in all animals for 15 minutes when it was accumulated on the average 1.03% of the administered dose. Plateau of 99mTc-Nanocis accumulation in the lymph node (average 2.05%) occurred at 2 hour of the study and remained almost on the same level (in average 2.3%) to 24 hours. Thus, the experimental study of a new domestic radiopharmaceutical showed

  12. Quantitative simultaneous 111In/99mTc SPECT-CT of osteomyelitis

    PubMed Central

    Cervo, Morgan; Gerbaudo, Victor H.; Park, Mi-Ae; Moore, Stephen C.

    2013-01-01

    Purpose: A well-established approach for diagnostic imaging of osteomyelitis (OM), a bone infection, is simultaneous SPECT-CT of 99mTc sulfur colloid (SC) and 111In white blood cells (WBC). This method provides essentially perfect spatial registration of the tracers within anatomic sites of interest. Currently, diagnosis is based purely on a visual assessment—where relative discordance between 99mTc and 111In uptake in bone, i.e., high 111In and low 99mTc, suggests OM. To achieve more quantitative images, noise, scatter, and crosstalk between radionuclides must be addressed through reconstruction. Here the authors compare their Monte Carlo-based joint OSEM (MC-JOSEM) algorithm, which reconstructs both radionuclides simultaneously, to a more conventional triple-energy window-based reconstruction (TEW-OSEM), and to iterative reconstruction with no compensation for scatter (NC-OSEM). Methods: The authors created numerical phantoms of the foot and torso. Multiple bone-infection sites were modeled using high-count Monte Carlo simulation. Counts per voxel were then scaled to values appropriate for 111In WBC and 99mTc SC imaging. Ten independent noisy projection image sets were generated by drawing random Poisson deviates from these very low-noise images. Data were reconstructed using the two iterative scatter-compensation methods, TEW-OSEM and MC-JOSEM, as well as the uncorrected method (NC-OSEM). Mean counts in volumes of interest (VOIs) were used to evaluate the bias and precision of each method. Data were also acquired using a phantom, approximately the size of an adult ankle, consisting of regions representing infected and normal bone marrow, within a bone-like attenuator and surrounding soft tissue; each compartment contained a mixture of 111In and 99mTc. Low-noise data were acquired during multiple short scans over 29 h on a Siemens Symbia T6 SPECT-CT with medium-energy collimators. Pure 99mTc and 111In projection datasets were derived by fitting the acquired

  13. 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. )

    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.

  14. Choledochal cyst complicated by acute cholecystitis and bypass obstruction: diagnostic role of Tc-99m-HIDA cholescintigraphy

    SciTech Connect

    Weissmann, H.S.; Gold, M.; Goldstein, R.D.; Sugarman, L.A.; Freeman, L.M.

    1981-09-01

    An unusual case of malignant degeneration of a choledochal cyst is presented. The presence of acute cholecystitis with the cystic duct originating from the cyst as well as the subsequent obstruction of the cyst-jejunal surgical anastomosis was readily detected with Tc-99m-dimethyl-iminodiacetic (Tc-99m-HIDA) cholescintigraphy.

  15. 76 FR 44899 - Astoria Generating Company, L.P and TC Ravenswood, LLC v. New York Independent System Operator...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-27

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Astoria Generating Company, L.P and TC Ravenswood, LLC v. New York... Federal Energy Regulatory Commission (Commission), Astoria Generating Company, L.P. and TC Ravenswood,...

  16. Botany Facility. Thermal Control (TC) subsystem test report on experiment container of laboratory model and breadboard centrifuge

    NASA Astrophysics Data System (ADS)

    Fischer, W.

    1986-11-01

    The Botany Facility TC (Thermal Control or Thermocouple) subsystem was tested in the environmental laboratory. All data could be generated within the required accuracy and to the required extent. The TC-subsystems of the Laboratory Model and Experiment Container and Centrifuge were successfully tested.

  17. 78 FR 30269 - Foreign-Trade Zone 129-Bellingham, Washington; Authorization of Production Activity; T.C. Trading...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-22

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

  18. Development of (99m)Tc-Labeled Pyridyl Benzofuran Derivatives To Detect Pancreatic Amylin in Islet Amyloid Model Mice.

    PubMed

    Yoshimura, Masashi; Ono, Masahiro; Watanabe, Hiroyuki; Kimura, Hiroyuki; Saji, Hideo

    2016-06-15

    While islet amyloid deposition comprising amylin is one of pathological hallmarks of type 2 diabetes mellitus (T2DM), no useful amylin-imaging probe has been reported. In this study, we evaluated two (99m)Tc-labeled pyridyl benzofuran derivatives as novel amylin-imaging probes using the newly established islet amyloid model mouse. Binding experiments in vitro demonstrated that [(99m)Tc]1 displayed a higher affinity for amylin aggregates than [(99m)Tc]2. Autoradiographic studies using human pancreas sections with T2DM revealed that [(99m)Tc]1 clearly labeled islet amyloid in T2DM pancreatic sections, while [(99m)Tc]2 did not. Although the initial uptake of [(99m)Tc]1 by the normal mouse pancreas was low (0.74%ID/g at 2 min post-injection), [(99m)Tc]1 showed higher retention in the model mouse pancreas than that of the normal mouse, and exhibited strong binding to amylin aggregates in the living pancreas of the model mice. These results suggest that [(99m)Tc]1 is a potential imaging probe targeting islet amyloids in the T2DM pancreas. PMID:27219875

  19. 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.

  20. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2015-10-01

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

  2. Role of 99mTc-Sulesomab Immunoscintigraphy in the Management of Infection following Deep Brain Stimulation Surgery

    PubMed Central

    Real, Raquel; Linhares, Paulo; Fernandes, Hélder; Rosas, Maria José; Gago, Miguel F.; Pereira, Jorge; Vaz, Rui

    2011-01-01

    Infection constitutes a serious adverse event in patients submitted to deep brain stimulation, often leading to removal of the device. We set to evaluate the potential role of immunoscintigraphy with 99mTc-labelled antigranulocyte antibody fragments (99mTc-sulesomab) in the management of infection following DBS. 99mTc-sulesomab immunoscintigraphy seems to correlate well with the presence and extent of infection, thus contributing to differentiate between patients who should remove the hardware entirely at presentation and those who could undergo a more conservative approach. Also, 99mTc-sulesomab immunoscintigraphy has a role in determining the most appropriate timing for reimplantation. Finally, we propose an algorithm for the management of infection following DBS surgery, based on the results of the 99mTc-sulesomab immunoscintigraphy. PMID:22028965

  3. Splenic scintigraphy using Tc-99m-labeled heat-denatured red blood cells in pediatric patients: concise communication

    SciTech Connect

    Ehrlich, C.P.; Papanicolaou, N.; Treves, S.; Hurwitz, R.A.; Richards, P.

    1982-03-01

    Ten children underwent splenic imaging with heat-denatured red blood cells labeled with technetium-99m (Tc-99m DRBC). The presenting problems included the heterotaxia syndrome, recurrent idiopathic thrombocytopenic purpura following splenectomy, mass in the left posterior hemithorax, and blunt abdominal trauma. In nine patients, the presence or absence of splenic tissue was established. A splenic hematoma was identified in the tenth patient. All patients were initially scanned with Tc-99m sulfur colloid (Tc-99m SC), and were selected for Tc-99m DRBC scintigraphy only after the results of the SC scans failed to establish the clinical problem beyond doubt. The availability of kits containing stannous ions, essential for efficient and stable labeling of red blood cells with Tc-99m and requiring only a small volume of blood, make splenic scintigraphy in children a relatively simple and definitive diagnostic procedure, when identification of splenic tissue is of clinical importance.

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

    SciTech Connect

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

    2011-02-01

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

  5. Liquid scintillation counting methodology for 99Tc analysis. A remedy for radiopharmaceutical waste

    SciTech Connect

    Khan, Mumtaz; Um, Wooyong

    2015-08-13

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

  6. Preparation, biodistribution, and scintigraphic evaluation of (99m)Tc-clindamycin: an infection imaging agent.

    PubMed

    Hina, Saira; Rajoka, Muhammad Ibrahim; Roohi, Samina; Haque, Asma; Qasim, Muhammad

    2014-10-01

    Bacterial infection is found to be the cause of death throughout the world. Nuclear medicine imaging with the help of radiopharmaceuticals has great potential for treating infections. In the present work, clindamycin, a lincosamide antibiotic, was labeled with technetium-99 m (~380 MBq). Clindamycin has been proven to be efficient for treating serious infections caused by bacteria such as Staphylococcus aureus. Quality control, characterization, biodistribution, and scintigraphy of radiolabeled clindamycin were done, and labeling efficiency was determined by ascending paper chromatography. More than 95 % labeling efficiency with technetium-99 m ((99m)Tc) was achieved at pH 6-7 while using 2.5-3 μg SnCl2 · H2O as a reducing agent and 100 μg of ligand at room temperature. The characterization of the compound was performed by using electrophoresis, HPLC and shake flask assay. Electrophoresis indicates the neutral behavior of (99m)Tc-clindamycin. HPLC analysis confirms the single specie of the labeled compound, while shake flask assay confirms high lipophilicity. The biodistribution studies of (99m)Tc-clindamycin were performed Sprague Dawley rats bearing bacterial infection. Scintigraphy and biodistribution studies showed a high uptake of (99m)Tc-clindamycin in the liver, heart, lung, and stomach as well as at S. aureus-infected sites in rabbits. PMID:25113549

  7. HIPed Tailored Ceramic Waste Forms for the Immobilization of Cs, Sr and Tc

    SciTech Connect

    Melody L. Carter; Martin W. A. Stewart; Eric R. Vance; Bruce D. Begg; Sam Moricca; Julia Tripp

    2007-09-01

    The Advanced Fuel Cycle Initiative is developing advanced technologies to allow for the safe and economical disposal of waste from nuclear reactors. An important element of this initiative is the separation of key radionuclides . One of the systems being developed to separate key radionuclides is the UREX+1 process. The Tc and Cs/Sr solutions from UREX+1 process will require treatment and solidification for managed storage. This paper illustrates the benefits of HIPed tailored ceramic waste forms, to provide for the immobilization of separated Cs, Sr and Tc. Experimental data are presented for a Cs and Sr-bearing hollandite-rich tailored ceramic prepared with 12 wt% waste (on an oxide basis). Normalized MCC-1 type leach testing at 90oC for 28 days revealed extremely low Cs and Sr release rates of 0.003 and 0.004 g/m2/day respectively. Experimental data on the immobilization of Tc in titanate ceramics containing up to 40wt% TcO2 are also be presented.

  8. Tc-99m MDP bone scintigraphy in a case of Touraine-Solente-Gole syndrome.

    PubMed

    Mudalsha, Ravina; Jacob, Mj; Jora, Charu; Pandit, Ag

    2011-01-01

    Pachydermoperiostosis is a form of primary hypertrophic osteoarthropathy, also known as Touraine-Solente-Gole syndrome. It is a rare disease. In this report, we present the case of a 29-year-old man with this rare disorder, having significant findings on Tc-99m methylene diphosphonate bone scan. PMID:21969783

  9. Tc-99m MDP bone scintigraphy in a case of Touraine-Solente-Gole syndrome

    PubMed Central

    Mudalsha, Ravina; Jacob, MJ; Jora, Charu; Pandit, AG

    2011-01-01

    Pachydermoperiostosis is a form of primary hypertrophic osteoarthropathy, also known as Touraine-Solente-Gole syndrome. It is a rare disease. In this report, we present the case of a 29-year-old man with this rare disorder, having significant findings on Tc-99m methylene diphosphonate bone scan. PMID:21969783

  10. Tests of a GM Cryocooler and high Tc leads for use on the ALS superbend magnets

    SciTech Connect

    Zbasnik, J.; Green, M.A.; Hoyer, E.H.; Taylor, C.E.; Chen, J.Y.; Wang, S.T.

    1999-07-09

    A 1.5 W (at the second stage) Gifford McMahon (GM) cryocooler was selected for cooling the superconducting SuperBend dipoles for the Advanced Light Source (ALS) at Berkeley. A GM cryocooler is a reasonable choice if conduction cooled leads are used to provide current to the superconducting magnet. The expected parasitic heat leaks are expected to range from 0.1 to 0.5 W at 4.2 K depending on the temperature of the shield and the cold mass support intercepts. Heat flow to 4 K down the SuperBend 350 A high Tc superconducting leads is expected to vary from 0.11 to 0.35 W depending on the intercept temperature and the current in the leads. The high Tc leads are designed to carry 350 A without significant resistive heating when the upper end of the lead is at 80 K. The 1.5 W cryocooler is expected to provide 45 to 50 W of refrigeration at the first stage at 50 K. The parasitic beat load into the first stage of the cryocooler will be about 8 W. The heat flow from 300 K down the upper copper leads is expected to be around 30 W. The cryocooler and high Tc lead test will measure the penormance of the cryocooler and the high Tc leads. The heat leak down the cryocooler, when it is not operating, is also of interest.

  11. 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

    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)

  12. Abnormal Tc-99m-MDP/GA-67 scan patterns in association with active chronic osteomyelitis

    SciTech Connect

    Tumeh, S.S.; Aliabadi, P.; Weissman, B.; McNeil, B.J.

    1985-05-01

    In this study the authors reviewed data from 136 patients (pts) in order to refine the interpretive criteria used to diagnose active osteomyelitis (AOM) in patients with previous bone disease (e.g., old osteomyelitis, fractures, orthopedic devices excluding prostheses). They evaluated bone (Tc-99mMDP) and gallium 67 studies and obtained followup in all pts. AOM was diagnosed by surgery or biopsy and culture in 49 pts and was excluded by the same criteria in 16 pts. An additional 71 pts had the diagnosis excluded by followup clinical criteria. Five patterns were found. T1: abnormal Tc-99m-MDP, normal Ga-67. T2: diffuse increased uptake of both radiopharmaceuticals with Tc-99m-MDP greater than Ga-67. T3: different geographic distribution, but similar intensities of uptake of both. T4: very similar uptake and distribution of both. T5: Ga-67 exceeded Tc-99m-MDP. The authors conclude that T5 is diagnostic of AOM, T3 and T4 raise the probability of AOM than before scanning, T1 and T2 decrease it.

  13. 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

  14. Exploring the Potential of (99m)Tc(CO)3-Labeled Triazolyl Peptides for Tumor Diagnosis.

    PubMed

    Gaonkar, Raghuvir H; Ganguly, Soumya; Baishya, Rinku; Dewanjee, Saikat; Sinha, Samarendu; Gupta, Amit; Ganguly, Shantanu; Debnath, Mita C

    2016-04-01

    In recent years the authors have reported on (99m)Tc(CO)3-labeled peptides that serve as carriers for biomolecules or radiopharmaceuticals to the tumors. In continuation of that work they report the synthesis of a pentapeptide (Met-Phe-Phe-Gly-His; pep-1), a hexapeptide (Met-Phe-Phe-Asp-Gly-His; pep-2), and a tetrapeptide (Asp-Gly-Arg-His; pep-3) and the attachment of 3-amino-1,2,4-triazole to the β carboxylic function of the aspartic acid unit of pep-2 and pep-3. The pharmacophores were radiolabeled in high yields with [(99m)Tc(CO)3(H2O)3](+) metal aqua ion, characterized for their stability in serum and saline, as well as in His solution, and found to be substantially stable. B16F10 cell line binding studies showed favorable uptake and internalization. In vivo behavior of the radiolabeled triazolyl peptides was assessed in mice bearing induced tumor. The (99m)Tc(CO)3-triazolyl pep-3 demonstrated rapid urinary clearance and comparatively better tumor uptake. Imaging studies showed visualization of the tumor using (99m)Tc(CO)3-triazolyl pep-3, but due to high abdominal background, low delineation occurred. Based on the results further experiments will be carried out for targeting tumor with triazolyl peptides. PMID:27093344

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

    SciTech Connect

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

    1981-08-01

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

  16. Differential concentration of Technetium-99 (99Tc) in common intertidal molluscs with different food habits.

    PubMed

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

    2011-11-01

    Concentration of 99Tc has been measured in fucoids and molluscs, sampled in a sheltered intertidal at the southwest coast of Norway from February to November 2006. The concentrations of 99Tc in molluscs differed significantly between species. The filtering bivalve Mytilus edulis had the lowest concentrations with averages of 2.3-5.9 Bq kg(-1) d.w., while the herbivorous gastropods Littorinalittorina, Littorina obtusata and Patella vulgata had higher concentrations. P. vulgata and L. obtusata had the highest concentrations, 40-47 and 26-30 Bq kg(-1)d.w., respectively. L. obtusata has a specialized habit of living, and prefers to feed on fucoids. P. vulgata can graze extensively on the fucoid Ascophyllum nodosum when available. Fucoids are known to have very high uptake of 99Tc, and this was also found in the present study. The high 99Tc-concentrations of L. obtusata and P. vulgata are most likely due to their habit of feeding on fucoids. PMID:21925686

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

    SciTech Connect

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

    1984-06-01

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

  18. Renal dysplasia in infants: appearance on 99mTc DMSA scintigraphy.

    PubMed

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

    1995-01-01

    Infantile renal dysplasias, including multicystic dysplastic kidneys (MCDK), are reported rarely to accumulate radiopharmaceuticals on renal scintigraphy. 99mTc DMSA is a highly sensitive tracer for detecting functioning renal cortical tissue and may be more suited to studying renal dysplasia than 99mTc DTPA. We reviewed the ultrasound studies and 99mTc DMSA scintigrams of 42 infants (age range 1-12 months) with known or suspected MCDK. Overall, uptake on 99mTc DMSA scintigraphy was evident in 6/41 (15%) dysplastic kidneys. Of the 18 patients who underwent nephrectomy, histopathological examination revealed that uptake correlated closely with the presence of mature renal cortical tissue in the affected kidney. Our study shows that a small, but significant number of MCDK will show low-grade uptake on DMSA scintigraphy. This finding may be relevant given the reliance placed on renal scintigraphy in planning treatment for infants with suspected MCDK, particularly with the increasing trend for the non-operative management of this condition. PMID:7491206

  19. [A case of stunned myocardium with marked 99mTc-PYP accumulation].

    PubMed

    Aoki, T; Nishikawa, H; Motoyasu, M; Shimizu, Y; Fukui, A; Ono, N; Kakuta, Y; Konishi, T; Nakano, T

    1993-01-01

    A 71-year-old woman with unstable angina was admitted to our department. Upon admission, electrocardiography revealed a QS pattern in Leads V1-V3. Left ventriculography disclosed akinesis of the anterior wall and the septum. Myocardial scintigraphy with 99mTc-pyrophosphate (PYP) revealed marked accumulation (Parkey's grade III) in the anterior wall, septum and apical region. Coronary arteriography revealed stenosis (99% with delay) in the LAD #6. Based on these findings, we performed percutaneous transluminal coronary angioplasty (PTCA) on this patient. About 3 months later, the patient underwent PTCA again because stenosis had recurred. The resting 201Tl myocardial scintigram, taken immediately after the first PTCA, demonstrated complete defects in the anterior wall, septum and apical region. After the second PTCA, no stenosis was observed. About 1 year later, the wall motion returned to normal (except in part of the apical region), suggesting that this was a case of stunned myocardium. On the same occasion, the 201Tl uptake was normal except in the apical region. The present case was regarded as stunned myocardium which demonstrated marked radioactivity accumulation when examined by 99mTc-PYP myocardial scintigraphy. In the past, 99mTc-PYP has been thought to be incorporated into irreversibly impaired myocardium (e.g., in cases of acute myocardial infarction). The uptake of 99mTc-PYP into stunned myocardium has not been reported before. Thus, this case is rare and noteworthy. PMID:8455342

  20. [The pathophysiologic basis for the incorporation of 99mTc-pyrophosphate into myocardial infarct].

    PubMed

    Duska, F; Hadas, L; Volenec, K; Palicka, V; Mazurová, Y; Vizd'a, J; Kafka, P; Urbanová, E; Kuba, M; Veverková, O

    1989-08-01

    The investigation studied the relation of 99mTc-pyrophosphate incorporation (99mTc-PYP) into experimental, 48-hours old myocardial infarction in dogs to tissue vascular supply and to the extent of necrotic tissue. The experimental myocardial infarction was induced in five animals during an operation by the ligation RIVA. The myocardial blood supply was measured in tissue samples, taken from transverse sections of the infarction by means of 86Rb captation. The extent of myocytolysis was measured by depletion of tissue creatine kinase (CK). In the subendocardial layer of the infarction it became obvious that 99mTc-PYP incorporation was proportional to the decrease of tissue blood supply. No relation between the extent of necrosis and the incorporation of the radioactive chemical was demonstrated. The accumulation of 99mTc-PYP requires the necrosis to be present, but its extent apparently does not influence the intensity of incorporation. In the subepicardial infarction layer there was neither a relation of the radioactive chemical cumulation to the blood flow, nor to the extent of the necrosis proved. PMID:2551518

  1. Acute subendocardial infarction with diffuse intense Tc-99m PYP uptake and minimal Tl-201 abnormality.

    PubMed

    Taki, J; Taki, S; Ichiyanagi, K; Akashi, Y; Hisada, K

    1992-08-01

    Tc-99m PYP scintigraphy performed on a patient with severe anterior chest pain showed diffuse intense uptake with central decreased activity corresponding to the left ventricular cavity. Tl-201 myocardial perfusion scintigraphy at rest revealed a minimal perfusion abnormality with decreased apical uptake in the lateral view. Because of these findings, diffuse subendocardial infarction was suggested. PMID:1387053

  2. 78 FR 40824 - Proposed Collection; Comment Request for Form 8038-TC

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-08

    ...(c)(2)(A)). Currently, the IRS is soliciting comments concerning Form 8038-TC, Information Return for... through the internet, at Allan.M.Hopkins@irs.gov . SUPPLEMENTARY INFORMATION: Title: Information Return..., Information Return for Tax-Exempt Private Activity Bond Issues. Current Actions: There are no changes...

  3. Synthesis and Evaluation of (99m)Tc-Labeled Dimeric Folic Acid for FR-Targeting.

    PubMed

    Guo, Zhide; Gao, Mengna; Song, Manli; Shi, Changrong; Zhang, Pu; Xu, Duo; You, Linyi; Zhuang, Rongqiang; Su, Xinhui; Liu, Ting; Du, Jin; Zhang, Xianzhong

    2016-01-01

    The folate receptor (FR) is overexpressed in a wide variety of human tumors. In our study, the multimeric concept was used to synthesize a dimeric folate derivative via a click reaction. The novel folate derivative (HYNIC-D₁-FA₂) was radiolabeled with (99m)Tc using tricine and trisodium triphenylphosphine-3,3',3″-trisulfonate (TPPTS) as coligands ((99m)Tc-HYNIC-D₁-FA₂) and its in vitro physicochemical properties, ex vivo biodistribution and in vivo micro-SPECT/CT imaging as a potential FR targeted agent were evaluated. It is a hydrophilic compound (log P = -2.52 ± 0.13) with high binding affinity (IC50 = 19.06 nM). Biodistribution in KB tumor-bearing mice showed that (99m)Tc-HYNIC-D₁-FA₂ had high uptake in FR overexpressed tumor and kidney at all time-points, and both of them could obviously be inhibited when blocking with free FA in the blocking studies. From the in vivo micro-SPECT/CT imaging results, good tumor uptake of (99m)Tc-HYNIC-D₁-FA₂ was observed in KB tumor-bearing mice and it could be blocked obviously. Based on the results, this new radiolabeled dimeric FA tracer might be a promising candidate for FR-targeting imaging with high affinity and selectivity. PMID:27338334

  4. Liver metastases of breast carcinoma detected on /sup 99m/Tc-methylene diphosphonate bone scan

    SciTech Connect

    Baumert, J.E.; Lantieri, R.L.; Horning, S.; McDougall, I.R.

    1980-02-01

    The accumulation of bone-seeking radiopharmaceuticals has been reported in liver metastases from colon carcinoma and oat cell carcinoma of the lung. Two patients with breast carcinoma in whom hepatic metastases were visualized on /sup 99m/Tc-methylene diphosphonate bone images are described. This has not been previously reported.

  5. (99m)Tc-bioorthogonal click chemistry reagent for in vivo pretargeted imaging.

    PubMed

    García, María Fernanda; Zhang, Xiuli; Shah, Manankumar; Newton-Northup, Jessica; Cabral, Pablo; Cerecetto, Hugo; Quinn, Thomas

    2016-03-15

    Metal-free click chemistry has become an important tool for pretargeted approaches in the molecular imaging field. The application of bioorthogonal click chemistry between a pretargeted trans-cyclooctene (TCO) derivatized monoclonal antibody (mAb) and a (99m)Tc-modified 1,2,4,5-tetrazine for tumor imaging was examined in vitro and in vivo. The HYNIC tetrazine compound was synthesized and structurally characterized, confirming its identity. Radiolabeling studies demonstrated that the HYNIC tetrazine was labeled with (99m)Tc at an efficiency of >95% and was radiochemically stable. (99m)Tc-HYNIC tetrazine reacted with the TCO-CC49 mAb in vitro demonstrating its selective reactivity. In vivo biodistribution studies revealed non-specific liver and GI uptake due to the hydrophobic property of the compound, however pretargeted SPECT imaging studies demonstrated tumor visualization confirming the success of the cycloaddition reaction in vivo. These results demonstrated the potential of (99m)Tc-HYNIC-tetrazine for tumor imaging with pretargeted mAbs. PMID:26875936

  6. Use of 99mTc-doxorubicin scintigraphy in females with breast cancer: a pilot study

    PubMed Central

    Araujo, F I; Proença, F P P; Ferreira, C G; Ventilari, S C; Rosado de Castro, P H; Moreira, R D; Fonseca, L M B; Gutfilen, B

    2015-01-01

    Objective: Doxorubicin (Eurofarma, São Paulo, Brazil) is an antitumour agent widely used in the treatment of breast cancer and can be used for tumour tracking when labelled with a radionuclide. Here, we present the results obtained with technetium-99m (99mTc)-doxorubicin, using the direct method, to evaluate its uptake in breast cancer. Methods: Four females with confirmed breast carcinoma diagnosis and breast image reporting and data system Category 5 on mammography underwent whole-body and thorax single-photon emission CT/CT imaging 1 and 3 h after 99mTc-doxorubicin administration. Results: We observed increased uptake in breast carcinoma lesions and elimination via renal and hepatic pathways. Conclusion: These preliminary results suggest that 99mTc-doxorubicin may be a promising radiopharmaceutical for the evaluation of patients with breast cancer. Further studies are ongoing. Advances in knowledge: To our knowledge, this is the first study to evaluate the use of a directly labelled doxorubicin tracer in humans. 99mTc-doxorubicin could provide information on the response of tumours to doxorubicin. PMID:26111270

  7. 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.

  8. Interplay of 3 d-5 d interactions in high-TC osmium-based double perovskites

    NASA Astrophysics Data System (ADS)

    Taylor, A. E.; Calder, S.; Morrow, R.; Woodward, P. M.; Yan, J. Q.; Winn, B.; Lumsden, M. D.; Christianson, A. D.

    2015-03-01

    In 3d-5d systems the strongly magnetic 3d orbitals and extended 5d orbitals with enhanced spin-orbit coupling lead to a range of high TC magnetic states and novel behavior not present in systems consisting solely of 3d or 5d ions. The two distinct octahedral sites in double perovskites A2 BB 'O6 allow an ordered 3d-5d structure to form, providing a variety of systems to be investigated. Unravelling the interactions controlling these systems, however, is an open challenge. The highest known TC in such a system, 725K, is found in insulator Sr2CrOsO6. This questions the theory for high-TCs in systems such as TC=400K Sr2FeReO6 which relies on half-metallic behavior. To unravel the nature of the interactions in 3d-5d systems, we have studied the series of compounds Sr2 X OsO6. We have utilized elastic and inelastic neutron scattering to probe the spin states in the systems, and therefore test predictions that the magnetic interactions are controlled by a frustrated AFM Heisenberg model. By studying the series, we are able to relate changes in the spin wave spectrum to dramatic changes in the magnetic order from TN = 95 K antiferromagnetism to TC = 725 K ferrimagnetism.

  9. Localization of /sup 99m/Tc methylene disphosphonate within synovial fluid in osteosarcoma

    SciTech Connect

    Sandler, M.S.; Heyman, S.; Watts, H.

    1984-08-01

    Extraosseous uptake of /sup 99m/Tc phosphate bone scanning agents has been reported in a wide variety of lesions, including malignant effusions. A case of uptake of bone scanning agent within synovial fluid in a joint involved with osteosarcoma is reported.

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

    SciTech Connect

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

    1983-05-01

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

  11. Removal of TcO4(-) ions from solution: materials and future outlook.

    PubMed

    Banerjee, Debasis; Kim, Dongsang; Schweiger, Michael J; Kruger, Albert A; Thallapally, Praveen K

    2016-05-21

    Technetium mainly forms during artificial nuclear fission; it exists primarily as TcO4(-) in nuclear waste, and it is among the most hazardous radiation-derived contaminants because of its long half-life (t1/2 = 2.13 × 10(5) years) and environmental mobility. The high water solubility of TcO4(-) (11.3 mol L(-1) at 20 °C) and its ability to readily migrate within the upper layer of the Earth's crust make it particularly hazardous. Several types of materials, namely resins, molecular complexes, layered double hydroxides, and pure inorganic and metal-organic materials, have been shown to be capable of capturing TcO4(-) (or other oxoanions) from solution. In this review, we give a brief description about the types of materials that have been used to capture TcO4(-) and closely related oxyanions so far and discuss the possibility of using metal-organic frameworks (MOFs) as next-generation ion-exchange materials for the stated application. In particular, with the advent of ultra-stable MOF materials, in conjunction with their chemical tunability, MOFs can be applied to capture these oxyanions under real-life conditions. PMID:26947251

  12. 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.

  13. Soft tissue metastases and lung cancer recurrence detected by Tc-99m depreotide scintigraphy.

    PubMed

    Miliziano, John S; Bradley, Yong C

    2002-06-01

    A 63-year-old woman with previously treated stage I lung cancer was reexamined 5 years later for recurrence. A conventional work-up using computed tomographic scanning and transbronchial biopsy showed nothing abnormal. A Tc-99m depreotide scan, however, led to a noninvasive diagnosis of lung cancer recurrence with metastases, and it directed a noninvasive tissue diagnosis. PMID:12045431

  14. Kit for the selective labeling of red blood cells in whole blood with .sup.9 TC

    DOEpatents

    Srivastava, Suresh C.; Babich, John W.; Straub, Rita; Richards, Powell

    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.

  15. Horseshoe kidney mimicking cross-fused ectopia on 99mTc-EC renal dynamic scintigraphy

    PubMed Central

    Agarwal, Krishan Kant; Karunanithi, Sellam; Jain, Sachin; Tripathi, Madhavi

    2014-01-01

    The ‘horseshoe kidney’ is the most common renal fusion anomaly. In this disorder, two developed kidneys are connected to each other at the lower part and grow together. We report a case of horseshoe kidney mimicking cross-fused ectopia in 99mTc-EC renal dynamic scintigraphy. PMID:24761069

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

    SciTech Connect

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

    1987-05-01

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

  17. The role of kidney uptake of Tc-99m pertechnetate during quantitation of gastric scintigraphy

    SciTech Connect

    Wasserman, H.J.; Klopper, J.F.; Erlank, P.

    1984-07-01

    It is shown that during quantitative gastric scintigraphy with Tc-99m pertechnetate significant errors may occur if kidney uptake is ignored. The magnitude of the error was assessed in 12 patients, and could lead to an over-estimation of gastric uptake by up to 20%.

  18. 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

  19. Mechanism of localization of 99mTc-labeled pyrophosphate and tetracycline in infarcted myocardium.

    PubMed

    Dewanjee, M K; Kahn, P C

    1976-07-01

    The gross and subcellular localizations of 99mTc-labeled pyrophosphate and tetracycline in myocardial infarcts were studied in a rabbit model. Experiments utilizing double-nuclide labeling were carried out using a useful mapping technique. Concentration of the various chelates decreases in an expected manner from the center of the infarcted area toward its periphery, but it is higher near the epicardial surface than toward the endocardium. Technetium-99m-pyrophosphate is concentrated in the same infarcted areas as 45Ca ion or 32P-pyrophosphate, but to a much greater degree. The uptake is dependent on both the degree of necrosis and residual blood flow. Gel filtration experiments with rabbit serum indicate that 99mTc-tagged pyrophosphate, tetracycline, and diphosphonate are mainly protein-bound, whereas 32P-pyrophosphate is not. Subcellular localization studies show that 99mTc-tetracycline and 99mTc-pyrophosphate are bound primarily to soluble protein, and only a small fraction is associated with nuclei, mitochondria, and microsomes. The uptake of technetium chelates in myocardial infarcts may be due to the formation of polynuclear complexes with denatured macromolecules rather than to the deposition of calcium in mitochrondria. PMID:178842

  20. Tc-99m complexes of new functionalized propylene amine oxime (PnAO) ligands

    SciTech Connect

    Pillai, M.R.A.; Kothari, K.; Ramamoorthy, N.

    1994-05-01

    Three new functionalized PnAO ligands, 3,3,9,9-tetra-methyl-6-R-4, 8-diazaundecane-2,10-dionedioxime (R=benzyl, p-nitrobenzyl and p-aminobenzyl) were synthesised. Tc-99m complexes of these ligands were prepared by direct reduction of Tc-99m O{sub 4}{sup -} using stannous tartrate in the presence of ligands at pH 9.0. Complexation yields were greater than 95% at 1h and 24h post preparation as assessed by ITLC, HPLC and extraction into CHCl3. All three of the complexes were neutral and lipophilic (logP > 2.0) and eluted as single peak from a RP HPLC column. Biodistribution studies of the Tc-99m complexes of the benzyl and the nitrobenzyl derivatives were done in Wistar rats. Both complexes showed brain uptake but were washed out of the brain similar to the behavior of Tc-99m PnAO.

  1. Arthrobacter aurescens TC1 Metabolizes Diverse s-Triazine Ring Compounds

    PubMed Central

    Strong, Lisa C.; Rosendahl, Charlotte; Johnson, Gilbert; Sadowsky, Michael J.; Wackett, Lawrence P.

    2002-01-01

    Arthrobacter aurescens strain TC1 was isolated without enrichment by plating atrazine-contaminated soil directly onto atrazine-clearing plates. A. aurescens TC1 grew in liquid medium with atrazine as the sole source of nitrogen, carbon, and energy, consuming up to 3,000 mg of atrazine per liter. A. aurescens TC1 is metabolically diverse and grew on a wider range of s-triazine compounds than any bacterium previously characterized. The 23 s-triazine substrates serving as the sole nitrogen source included the herbicides ametryn, atratone, cyanazine, prometryn, and simazine. Moreover, atrazine substrate analogs containing fluorine, mercaptan, and cyano groups in place of the chlorine substituent were also growth substrates. Analogs containing hydrogen, azido, and amino functionalities in place of chlorine were not growth substrates. A. aurescens TC1 also metabolized compounds containing chlorine plus N-ethyl, N-propyl, N-butyl, N-s-butyl, N-isobutyl, or N-t-butyl substituents on the s-triazine ring. Atrazine was metabolized to alkylamines and cyanuric acid, the latter accumulating stoichiometrically. Ethylamine and isopropylamine each served as the source of carbon and nitrogen for growth. PCR experiments identified genes with high sequence identity to atzB and atzC, but not to atzA, from Pseudomonas sp. strain ADP. PMID:12450818

  2. 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.

  3. Measurement of pulmonary epithelial permeability with /sup 99m/Tc-DTPA aerosol

    SciTech Connect

    Coates, G.; O'Brodovich, H.

    1986-10-01

    The rate at which inhaled aerosol of /sup 99m/Tc-diethylenetriamine pentaacetate (DTPA) leaves the lung by diffusion into the vascular space can be measured with a gamma camera or simple probe. In normal humans, /sup 99m/Tc-DTPA clears from the lung with a half time of about 80 minutes. Many acute and chronic conditions that alter the integrity of the pulmonary epithelium cause an increased clearance rate. Thus cigarette smoking, alveolitis from a variety of causes, adult respiratory distress syndrome (ARDS), and hyaline membrane disease (HMD) in the infant have all been shown to be associated with rapid pulmonary clearance of /sup 99m/Tc-DTPA. Rapid clearance is also promoted by increased lung volume and decreased surfactant activity. Although the mechanism of increased clearance in pathological states is not known, the /sup 99m/Tc-DTPA lung-clearance technique has great potential clinically, particularly in patients at risk from ARDS and HMD and in the diagnosis and follow-up of alveolitis. 58 references.

  4. 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.

  5. Theoretical models of flux pinning and flux motion in high-{Tc} superconducting oxides

    SciTech Connect

    Welch, D.O.

    1991-12-31

    Various issues involved in the development of phenomenological models of flux pinning and motion in high-{Tc} oxides are discussed. A simplified model is presented for the critical current density and is used to examine the question of whether flux flow results from an instability due to plasticity of the flux-line array or from pin breaking.

  6. Theoretical models of flux pinning and flux motion in high- Tc superconducting oxides

    SciTech Connect

    Welch, D.O.

    1991-01-01

    Various issues involved in the development of phenomenological models of flux pinning and motion in high-{Tc} oxides are discussed. A simplified model is presented for the critical current density and is used to examine the question of whether flux flow results from an instability due to plasticity of the flux-line array or from pin breaking.

  7. Cyclotron production of ⁹⁹mTc: recycling of enriched ¹⁰⁰Mo metal targets.

    PubMed

    Gagnon, K; Wilson, J S; Holt, C M B; Abrams, D N; McEwan, A J B; Mitlin, D; McQuarrie, S A

    2012-08-01

    There is growing interest in the large scale cyclotron production of (99m)Tc via the (100)Mo(p,2n)(99m)Tc reaction. While the use and recycling of cyclotron-irradiated enriched molybdenum targets has been reported previously in the context of (94m)Tc production, to the best of our knowledge, previous recycling studies have been limited to the use of oxide targets. To facilitate reuse of high-power enriched (100)Mo targets, this work presents and evaluates a strategy for recycling of enriched metallic molybdenum. For the irradiated (100)Mo targets in this study, an overall metal to metal recovery of 87% is reported. Evaluation of "new" and "recycled" (100)Mo revealed no changes in the molybdenum isotopic composition (as measured via ICP-MS). For similar irradiation conditions of "new" and "recycled" (100)Mo, (i.e. target thicknesses, irradiation time, and energy), comparable levels of (94g)Tc, (95g)Tc, and (96g)Tc contaminants were observed. Comparable QC specifications (i.e. aluminum ion concentration, pH, and radiochemical purity) were also reported. We finally note that [(99m)Tc]-MDP images obtained by comparing MDP labelled with generator-based (99m)Tc vs. (99m)Tc obtained following the irradiation of recycled (100)Mo demonstrated comparable biodistribution. With the goal of producing large quantities of (99m)Tc, the proposed methodology demonstrates that efficient recycling of enriched metallic (100)Mo targets is feasible and effective. PMID:22750197

  8. Lung function declines in patients with pulmonary sarcoidosis and increased respiratory epithelial permeability to sup 99m Tc-DTPA

    SciTech Connect

    Chinet, T.; Dusser, D.; Labrune, S.; Collignon, M.A.; Chretien, J.; Huchon, G.J. )

    1990-02-01

    Respiratory epithelial clearance of {sup 99m}Tc-DTPA (RC-Tc-DTPA) and pulmonary function tests (PFT) were determined at intervals of 6 or 12 months in 37 untreated, nonsmoking patients with sarcoidosis over a period of 6 to 36 months. PFT included the measurements of total lung capacity (TLC), vital capacity (VC), FEV1, and diffusing capacity for carbon monoxide. No difference was found between the respiratory clearance of {sup 113m}In-DTPA (2.25 +/- 1.00%/min) and RC-Tc-DTPA (2.29 +/- 1.11%/min) in eight patients with pulmonary sarcoidosis. Pulmonary function decreased 15% or more in at least 2 function tests during 11 follow-up periods, but it remained stable during 47 follow-up periods. In patients whose lung function deteriorated, RC-Tc-DTPA increased to 3.51 +/- 1.55%/min; in contrast, in patients whose lung function remained stable, regardless of the initial values, RC-Tc-DTPA was normal (1.00 +/- 0.50%/min; p less than 0.001). In eight patients who were treated with corticosteroids, RC-Tc-DTPA decreased from 3.48 +/- 1.31%/min to 1.56 +/- 0.64%/min (p less than 0.001), and PFT improved. We conclude that in nonsmokers with pulmonary sarcoidosis, increased RC-Tc-DTPA is not related to dissociation of 99mTc from DTPA, RC-Tc-DTPA is increased when pulmonary function decreases, and, when increased, RC-Tc-DTPA decreases with corticosteroid therapy.

  9. Detection of ischemic myocardium with a new hypoxic tissue targeting tracer 99Tc(m)-HL91.

    PubMed

    Lü, Jiagao; Liu, Gang; Fang, Ya; Wu, Hua

    2006-01-01

    The imaging appearances of 99Tc(m)-HL91, a new hypoxic imaging agent, in ischemic myocardium were studied and the value of 99Tc(m)-HL91 in the evaluation of regional ischemic viable myocardium was explored. Acute myocardial ischemia models were made by coronary artery legations in 18 rats and randomly divided into 2 groups: 99Tc(m)-HL91 group and 99Tc(m)-MIBI group. Evan blue infusion during ischemia and TTC staining after operation were used to delineate the area of ischemic and viable myocardium. The isolated heart was sliced in the short axis and then autoradiography was performed. The electron microscopic examination was also done for the myocardial samples. 99Tc(m)-HL91 and 99Tc(m)-MIBI uptake activities (counts/g) were measured in the area of ischemic myocardium (T) and normal myocardium (NT) separately. The uptake ratios of 99Tc(m)-HL91 and that of 99Tc(m)-MIBI in ischemic myocardium were calculated as T/NT. It was found that the normal myocardium was blue and ischemic or infarct myocardium was negative with Evans blue in all experiment rats. Both the normal and ischemic myocardium was in red color with TTC staining. In the 99Tc(m)-HL91 group the ischemic myocardium showed much higher uptake over normal myocardium, that was demonstrated both in the autoradiography and quantitative analysis. The ischemic/normal activity ratios were 1.634 +/- 0.354. It was suggested that 99Tc(m)-HL91 might accumulate in ischemic and viable myocardium, which is helpful in the evaluation of hypoxic but viable myocardium and potentially used as a imaging agent to assess myocardial viability. PMID:16961269

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

    PubMed Central

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

    2015-01-01

    In-vitro labeling of RBC with 99mTc is an intricate procedure and there is always a need for an alternate blood pool imaging agent. The aim of this study was to prepare an effective nano sized liposome (NLs) similar to human RBC for blood pool scintigraphy. This study formulates PEG-NLs and non-PEG-NLs using film method plus high pressure homogenization technique. Biodistribution studies were performed on BALB/C mice 1, 4 and 24 h after tail vein injection of labeled NLs with 99mTc hexamethylpropylene-amine-oxime (99mTc-HMPAO). Planar images were acquired using a 256 × 256 matrix following99m Tc-HMPAO-NLs injection into ear vein of rabbits 1, 2 and 24 h later. SPECT images were obtained 15 minutes after the injection (64 slices, 30 second/projection). The mean diameter, zeta potential and polydispersity index (PDI) of the PEG-NLs and the NLs were (80.88 ± 0.594 nm, -12.5 ± 0.56 mv, 0.158 ± 0.025) and (94.14 ± 0.114 nm, -35.5 ± 0.67 mv and 0.198 ± 0.007), respectively. 99mTc-HMPAO-PEG-NLs showed a significant circulation tracer activity (7.74 ± 1.63%ID/g at 1 h and 4.9 ± 0.77 %ID/g at 4 h), with low liver accumulation (12.07 ± 3.66 %ID/g at 1 h and 14.85 ± 1.3 %ID/g at 4 h). Heart to liver, spleen and background ROIs (region of interests) for 99m Tc-HMPAO-PEG-NLs were 1.25, 4 and 4.28 respectively at 2 h which changed to 1.06, 1.75 and 2.51 respectively at 24 h. The 99mTc-HMPAO-PEG-NLs with a prolonged blood circulation time could be an excellent RBC alternative for scintigraphy and gastrointestinal bleeding. PMID:26664365

  11. {sup 99}Tc bioassay by inductively coupled plasma mass spectrometry (ICP-MS)

    SciTech Connect

    Lewis, L.A.

    1998-05-01

    A means of analyzing {sup 99}Tc in urine by inductively coupled plasma mass spectrometry (ICP-MS) has been developed. Historically, {sup 99}Tc analysis was based on the radiometric detection of the 293 keV E{sub Max} beta decay product by liquid scintillation or gas flow proportional counting. In a urine matrix, the analysis of{sup 99}Tc is plagued with many difficulties using conventional radiometric methods. Difficulties originate during chemical separation due to the volatile nature of Tc{sub 2}O{sub 7} or during radiation detection due to color or chemical quenching. A separation scheme for {sup 99}Tc detection by ICP-MS is given and is proven to be a sensitive and robust analytical alternative. A comparison of methods using radiometric and mass quantitation of {sup 99}Tc has been conducted in water, artificial urine, and real urine matrices at activity levels between 700 and 2,200 dpm/L. Liquid scintillation results based on an external standard quench correction and a quench curve correction method are compared to results obtained by ICP-MS. Each method produced accurate results, however the precision of the ICP-MS results is superior to that of liquid scintillation results. Limits of detection (LOD) for ICP-MS and liquid scintillation detection are 14.67 and 203.4 dpm/L, respectively, in a real urine matrix. In order to determine the basis for the increased precision of the ICP-MS results, the detection sensitivity for each method is derived and measured. The detection sensitivity for the {sup 99}Tc isotope by ICP-MS is 2.175 x 10{sup {minus}7} {+-} 8.990 x 10{sup {minus}9} and by liquid scintillation is 7.434 x 10{sup {minus}14} {+-} 7.461 x 10{sup {minus}15}. A difference by seven orders of magnitude between the two detection systems allows ICP-MS samples to be analyzed for a period of 15 s compared to 3,600 s by liquid scintillation counting with a lower LOD.

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

    PubMed Central

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

    2015-01-01

    Purpose This study aimed to explore the diagnostic performance of single photon emission computed tomography / computerized tomography (SPECT/CT) using a new radiotracer 99mTc-RGD-BBN for breast malignant tumor compared with 99mTc-3P4-RGD2. Methods 6 female patients with breast malignant tumors diagnosed by fine needle aspiration cytology biopsy (FNAB) who were scheduled to undergo surgery were included in the study. 99mTc-3P4-RGD2 and 99mTc-RGD-BBN were performed with single photon emission computed tomography (SPECT) at 1 hour after intravenous injection of 299 ± 30 MBq and 293 ± 32 MBq of radiotracers respectively at separate day. The results were evaluated by the Tumor to non-Tumor ratios (T/NT). 99mTc-RGD-BBN and 99mTc-3P4-RGD2 SPECT/CT images were interpreted independently by 3 experienced nuclear medicine physicians using a 3-point scale system. All of the samples were analyzed immunohistochemically to evaluate the integrin αvβ3 and gastrin-releasing peptide receptor (GRPR) expression. The safety, biodistribution and radiation dosimetry of 99mTc-RGD-BBN were also evaluated in the healthy volunteers. Results No serious adverse events were reported in any of the patients during the study. The effective radiation dose entirely conformed to the relevant standards. A total of 6 palpable malignant lesions were detected using 99mTc-RGD-BBN SPECT/CT with clear uptake. All malignant lesions were also detected using 99mTc-3P4-RGD2 SPECT/CT. The results showed that five malignant lesions were with clear uptake and the other one with barely an uptake. 4 malignant cases were found with both αvβ3 and GRPR expression, 1 case with only GRPR positive expression (integrin αvβ3 negative) and 1 case with only integrin αvβ3 positive expression (GRPR negative). Conclusion 99mTc-RGD-BBN is a safe agent for detecting breast cancer. 99mTc-RGD-BBN may have the potential to make up for the deficiency of 99mTc-3P4-RGD2 in the detection of breast cancer with only GRPR positive

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

    NASA Astrophysics Data System (ADS)

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

    2011-10-01

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

  14. CD73-mediated adenosine production promotes stem cell-like properties in mouse Tc17 cells.

    PubMed

    Flores-Santibáñez, Felipe; Fernández, Dominique; Meza, Daniel; Tejón, Gabriela; Vargas, Leonardo; Varela-Nallar, Lorena; Arredondo, Sebastián; Guixé, Victoria; Rosemblatt, Mario; Bono, María Rosa; Sauma, Daniela

    2015-12-01

    The CD73 ectonucleotidase catalyses the hydrolysis of AMP to adenosine, an immunosuppressive molecule. Recent evidence has demonstrated that this ectonucleotidase is up-regulated in T helper type 17 cells when generated in the presence of transforming growth factor-β (TGF-β), and hence CD73 expression is related to the acquisition of immunosuppressive potential by these cells. TGF-β is also able to induce CD73 expression in CD8(+) T cells but the function of this ectonucleotidase in CD8(+) T cells is still unknown. Here, we show that Tc17 cells present high levels of the CD73 ectonucleotidase and produce adenosine; however, they do not suppress the proliferation of CD4(+) T cells. Interestingly, we report that adenosine signalling through A2A receptor favours interleukin-17 production and the expression of stem cell-associated transcription factors such as tcf-7 and lef-1 but restrains the acquisition of Tc1-related effector molecules such as interferon-γ and Granzyme B by Tc17 cells. Within the tumour microenvironment, CD73 is highly expressed in CD62L(+) CD127(+) CD8(+) T cells (memory T cells) and is down-regulated in GZMB(+) KLRG1(+) CD8(+) T cells (terminally differentiated T cells), demonstrating that CD73 is expressed in memory/naive cells and is down-regulated during differentiation. These data reveal a novel function of CD73 ectonucleotidase in arresting CD8(+) T-cell differentiation and support the idea that CD73-driven adenosine production by Tc17 cells may promote stem cell-like properties in Tc17 cells. PMID:26331349

  15. Magnetism in EuBCO and YBCO vortex states near and below Tc

    NASA Astrophysics Data System (ADS)

    Schwartz, R.; Browne, M. C.; Boekema, C.

    2012-02-01

    By means of MaxEnt-μSR [1] analysis, we investigate transverse field μSR data [2] of EuBa2Cu3O7-δgEuBCO; Tc = 93 K). Our focus is on a temperature interval near Tc to search for precursor effects, [3] and for predicted [4a] pseudogap loop currents above and below Tc, already observed [4b] above Tc for GdBCO. Further, we continue to study the field-direction dependence of the predicted [5a] and observed [5b] antiferromagnetism (AF) below 0.5Tc for the vortex states in c-axis-oriented YBCO. This AF in and near the vortex cores is likely three-dimensional. In sum, magnetic roots of cuprate superconductivity are well plausible. Research is supported by LANL-DOE, REU-NSF and AFC. [4pt] [1] C Boekema and MC Browne, AIP Conf Proc #1073 (2008) 260.[0pt] [2] DW Cooke et al, Phys Rev B 39 (1989) 2748.[0pt] [3] B Aguilar, C Boekema et al, Bull Am Phys Soc 37 (1992).[0pt] [4a] CM Varma, Phys Rev Lett 83 (1999) 3538.[0pt] [4b] T Songatikamas et al, J Supercond & Novel Magn 23 (2010) 793.[0pt] [5a] S-C Zhang, Science 275 (1997) 1089; H-D Chen et al, Phys Rev B70 (2004) 024516.[0pt] [5b] C. Boekema et al, J Phys Conf Series, 150 (2009) 052022. http://jpcs.iop.org/LT25

  16. Determination of glomerular filtration rate with 99mTc-DTPA in clinical practice.

    PubMed

    Galli, G; Rufini, V; Meduri, G; Piraccini, R; D'Andrea, G

    1994-12-01

    In order to assess the practical reliability of glomerular filtration rate (GFR) determination with 99mTc-DTPA and plasma sampling, the authors compared the results obtained with 51Cr-EDTA and 99mTc-DTPA in 50 patients using five easily applied methods (two double-plasma-sample methods and three single-plasma-sample methods), and two kits with different compositions. It was observed that: 1) there is no difference between the results obtained with the two different kits. 2) Compared with 51Cr-EDTA the 99mTc-DTPA overestimates the result by about 2 mL/min: precision is slightly lower with 99mTc-DTPA than with 51Cr-EDTA but is sufficient for practical use. 3) The method recommended by the authors on the basis of this experience is the Russell's method with two samples. 4) The simplified methods with one sample give comparable results to the Russell's method for GFR levels between 50 and 115 mL/min, while the results are unsatisfactory below 50 mL/min. 5) Among the single-sample methods, the authors suggest that of Christensen and Groth. 6) A preliminary estimate of GFR (from the serum creatinine level, for instance) is useful for the choice between double-plasma-sample methods and simplified methods. In conclusion, the authors consider that the estimation of GFR with 99mTc-DTPA can be performed efficiently in clinical practice even when operating in absolutely routine conditions. PMID:7786917

  17. Synthesis, characterization and biological evaluation of (99m)Tc/Re-tricarbonyl quinolone complexes.

    PubMed

    Kydonaki, Theocharis E; Tsoukas, Evangelos; Mendes, Filipa; Hatzidimitriou, Antonios G; Paulo, António; Papadopoulou, Lefkothea C; Papagiannopoulou, Dionysia; Psomas, George

    2016-07-01

    New rhenium(I) tricarbonyl complexes with the quinolone antimicrobial agents oxolinic acid (Hoxo) and enrofloxacin (Herx) and containing methanol, triphenylphosphine (PPh3) or imidazole (im) as unidentate co-ligands, were synthesized and characterized. The crystal structure of complex [Re(CO)3(oxo)(PPh3)]∙0.5MeOH was determined by X-ray crystallography. The deprotonated quinolone ligands are bound bidentately to rhenium(I) ion through the pyridone oxygen and a carboxylate oxygen. The binding of the rhenium complexes to calf-thymus DNA (CT DNA) was monitored by UV spectroscopy, viscosity measurements and competitive studies with ethidium bromide; intercalation was suggested as the most possible mode and the DNA-binding constants of the complexes were calculated. The rhenium complex [Re(CO)3(erx)(im)] was assayed for its topoisomerase IIα inhibition activity and was found to be active at 100μM concentration. The interaction of the rhenium complexes with human or bovine serum albumin was investigated by fluorescence emission spectroscopy (through the tryptophan quenching) and the corresponding binding constants were determined. The tracer complex [(99m)Tc(CO)3(erx)(im)] was synthesized and identified by comparative HPLC analysis with the rhenium analog. The (99m)Tc complex was found to be stable in solution. Upon injection in healthy mice, fast tissue clearance of the (99m)Tc complex was observed, while both renal and hepatobiliary excretion took place. Preliminary studies in human K-562 erythroleukemia cells showed cellular uptake of the (99m)Tc tracer with distribution primarily in the cytoplasm and the mitochondria and less in the nucleus. These preliminary results indicate that the quinolone (99m)Tc/Re complexes show promise to be further evaluated as imaging or therapeutic agents. PMID:26795497

  18. 99mTc-DPD uptake reflects amyloid fibril composition in hereditary transthyretin amyloidosis

    PubMed Central

    Pilebro, Björn; Suhr, Ole B.; Näslund, Ulf; Westermark, Per; Lindqvist, Per; Sundström, Torbjörn

    2016-01-01

    Aims In transthyretin amyloid (ATTR) amyloidosis various principal phenotypes have been described: cardiac, neuropathic, or a mixed cardiac and neuropathic. In addition, two different types of amyloid fibrils have been identified (type A and type B). Type B fibrils have thus far only been found in predominantly early-onset V30M and in patients carrying the Y114C mutation, whereas type A is noted in all other mutations currently examined as well as in wild-type ATTR amyloidosis. The fibril type is a determinant of the ATTR V30M disease phenotype. 99mTc-DPD scintigraphy is a highly sensitive method for diagnosing heart involvement in ATTR amyloidosis. The objective of this study was to determine the relationship between ATTR fibril composition and 99mTc-DPD scintigraphy outcome in patients with biopsy-proven ATTR amyloidosis. Methods Altogether 55 patients with biopsy-proven diagnosis of ATTR amyloidosis and amyloid fibril composition determined were examined by 99mTc-DPD scintigraphy. The patients were grouped and compared according to their type of amyloid fibrils. Cardiovascular evaluation included ECG, echocardiography, and cardiac biomarkers. The medical records were scrutinized to identify subjects with hypertension or other diseases that have an impact on cardiac dimensions. Results A total of 97% with type A and none of the patients with type B fibrils displayed 99mTc-DPD uptake at scintigraphy (p < 0.001). Findings from analyses of cardiac biomarkers, ECG, and echocardiography, though significantly different, could not differentiate between type A and B fibrils in individual patients. Conclusion In ATTR amyloidosis, the outcome of 99mTc-DPD scintigraphy is strongly related to the patients’ transthyretin amyloid fibril composition. PMID:26849806

  19. (99m)Tc-DPD uptake reflects amyloid fibril composition in hereditary transthyretin amyloidosis.

    PubMed

    Pilebro, Björn; Suhr, Ole B; Näslund, Ulf; Westermark, Per; Lindqvist, Per; Sundström, Torbjörn

    2016-01-01

    Aims In transthyretin amyloid (ATTR) amyloidosis various principal phenotypes have been described: cardiac, neuropathic, or a mixed cardiac and neuropathic. In addition, two different types of amyloid fibrils have been identified (type A and type B). Type B fibrils have thus far only been found in predominantly early-onset V30M and in patients carrying the Y114C mutation, whereas type A is noted in all other mutations currently examined as well as in wild-type ATTR amyloidosis. The fibril type is a determinant of the ATTR V30M disease phenotype. (99m)Tc-DPD scintigraphy is a highly sensitive method for diagnosing heart involvement in ATTR amyloidosis. The objective of this study was to determine the relationship between ATTR fibril composition and (99m)Tc-DPD scintigraphy outcome in patients with biopsy-proven ATTR amyloidosis. Methods Altogether 55 patients with biopsy-proven diagnosis of ATTR amyloidosis and amyloid fibril composition determined were examined by (99m)Tc-DPD scintigraphy. The patients were grouped and compared according to their type of amyloid fibrils. Cardiovascular evaluation included ECG, echocardiography, and cardiac biomarkers. The medical records were scrutinized to identify subjects with hypertension or other diseases that have an impact on cardiac dimensions. Results A total of 97% with type A and none of the patients with type B fibrils displayed (99m)Tc-DPD uptake at scintigraphy (p < 0.001). Findings from analyses of cardiac biomarkers, ECG, and echocardiography, though significantly different, could not differentiate between type A and B fibrils in individual patients. Conclusion In ATTR amyloidosis, the outcome of (99m)Tc-DPD scintigraphy is strongly related to the patients' transthyretin amyloid fibril composition. PMID:26849806

  20. The functional hepatic volume assessed by 99mTc-GSA hepatic scintigraphy.

    PubMed

    Wu, J; Ishikawa, N; Takeda, T; Tanaka, Y; Pan, X Q; Sato, M; Todoroki, T; Hatakeyama, R; Itai, Y

    1995-11-01

    The accuracy of measurement of the functional hepatic volume by single photon emission computed tomography (SPECT) with 99mTc-galactosyl serum albumin (99mTc-GAS) was evaluated. 99mTc-GSA planar scintigraphic images were obtained dynamically and the hepatic SPECT imaging was then performed in 25 patients with hepatobiliary tumors. The patients were divided into 4 groups with normal hepatic function, and mild, moderate and severe hepatic dysfunction. The functional hepatic volume determined by SPECT was compared with the morphological hepatic volume determined by compute tomography. The ratio of the hepatic volumes obtained by the two methods was calculated. The mean hepatic volume ratio was 96.6 +/- 2.3% in the normal hepatic function group and 95.9 +/- 2.2% in the mild dysfunction group (n.s.). In both the moderate and severe hepatic dysfunction groups, the hepatic volume ratio was smaller than that in the normal group (87.9 +/- 5.2%, p < 0.0001, and 71.9 +/- 7.6%, p < 0.0001, respectively). There was a linear correlation between the hepatic volume ration and various indices of reserve hepatic function, such as LHL15 (r = 0.83, p < 0.0001), HH15(r = 0.74, p < 0.0001), and ICG15 (r = 0.75, p < 0.0005). These results indicate that the hepatic volume ratio is proportional to the severity of hepatic dysfunction, and suggest that the functional hepatic volume measured with 99mTc-GSA faithfully reflects the functioning hepatocyte mass. 99mTc-GSA scintigraphy and hepatic SPECT therefore provide information regarding global and regional reserve hepatic function. PMID:8770291

  1. Polymer embedded nanocrystalline titania sorbent for 99Mo-99mTc generator.

    PubMed

    Chakravarty, Rubel; Shukla, Rakesh; Gandhi, Shyamla; Ram, Ramu; Dash, Ashutosh; Venkatesh, Meera; Tyagi, A K

    2008-09-01

    A new sorbent material, polymer embedded nano crystalline titania (Titanium Polymer-TiP) has been developed, from titanium (IV) chloride and isopropyl alcohol, for the adsorption of 99Mo, which is a precursor to 99mTc, a workhorse in radio-pharmaceuticals. The infrared absorption spectra of the TiP showed peaks corresponding to Ti-O groups. X-ray diffraction pattern of the adsorbent corresponded to rutile TiO2. The surface area of this polymer was 30 m2/g with an average pore size of 40 nm. The average crystallite size of TiO2, embedded in polymer, was found to be 5 nm. TEM micrograph of the adsorbent revealed the network of polymer with dispersed titania phase. Potential of this adsorbent for the preparation of 99Mo-99mTc generator has been explored. 99Mo could be adsorbed on to the adsorbent column containing TiP at pH 1 from which 99mTC could be eluted with normal (0.9%) saline solution with an elution yield of approximately 80%. The quality of the 99mTcO4 obtained was in accordance with the international specifications applicable for radiopharmaceutical use. A process demonstration run was carried out with 1.1 GBq (30 mCi) 99Mo activity level making use of the above adsorbent and consistent results were obtained over a period of one week, which is generally the shelf life of 99MO-99mTC generator. PMID:19049039

  2. Predicting the sparticle spectrum from GUTs via SUSY threshold corrections with SusyTC

    NASA Astrophysics Data System (ADS)

    Antusch, Stefan; Sluka, Constantin

    2016-07-01

    Grand Unified Theories (GUTs) can feature predictions for the ratios of quark and lepton Yukawa couplings at high energy, which can be tested with the increasingly precise results for the fermion masses, given at low energies. To perform such tests, the renormalization group (RG) running has to be performed with sufficient accuracy. In su-persymmetric (SUSY) theories, the one-loop threshold corrections (TC) are of particular importance and, since they affect the quark-lepton mass relations, link a given GUT flavour model to the sparticle spectrum. To accurately study such predictions, we extend and generalize various formulas in the literature which are needed for a precision analysis of SUSY flavour GUT models. We introduce the new software tool SusyTC, a major extension to the Mathematica package REAP [1], where these formulas are implemented. SusyTC extends the functionality of REAP by a full inclusion of the (complex) MSSM SUSY sector and a careful calculation of the one-loop SUSY threshold corrections for the full down-type quark, up-type quark and charged lepton Yukawa coupling matrices in the electroweak-unbroken phase. Among other useful features, SusyTC calculates the one-loop corrected pole mass of the charged (or the CP-odd) Higgs boson as well as provides output in SLHA conventions, i.e. the necessary input for external software, e.g. for performing a two-loop Higgs mass calculation. We apply SusyTC to study the predictions for the parameters of the CMSSM (mSUGRA) SUSY scenario from the set of GUT scale Yukawa relations y_e/y_d=-1/2{-}^2,y_{μ }/y_s = 6 , and y_{τ }/y_b=-3/2 , which has been proposed recently in the context of SUSY GUT flavour models.

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

    PubMed

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

    2010-06-10

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

  4. Imaging Thromboembolism with Fibrin-Avid 99mTc-Peptide: Evaluation in Swine

    PubMed Central

    Aruva, Mohan R.; Daviau, Judy; Sharma, Shubh S.; Thakur, Mathew L.

    2006-01-01

    A pentapeptide, Gly-Pro-Arg-Pro-Pro, with high affinity for α-chain-fibrin was labeled with 99mTc (99mTc-TP850) and evaluated in swine to image experimental venous thromboembolism (deep vein thrombosis [DVT]) and pulmonary embolism (PE). Methods Scatchard analysis was performed to determine fibrin affinity for TP850 and the number of binding sites (receptors) per milligram of fibrin. DVT was induced in the left jugular vein and PE was induced by introducing a preformed autologous blood clot into the right atrium using a 7-French introducer sheath inserted into the right jugular vein. 99mTc-TP850 was injected at 4, 24, 48, 72, 96, or 120 h later. Animals were imaged for up to 4 h after injection, heparinized, and sacrificed. Lungs were extirpated, radiographed, and imaged, and the PE was removed. Other tissues, including blood and normal lungs, were harvested and, concomitantly, 99mTc was counted for determination of target-to-tissue ratios and the percentage injected dose per gram of tissue. Results The affinity for human fibrin was 10−9 mol/L and there were >1015 receptors per milligram of fibrin. DVT and PE were visualized for up to 4 h after injection with high DVT/blood (7.9–22.6), DVT/muscle (31.1–89.4), PE/blood (1–155), and PE/lung (0.8–245) ratios. Thereafter, the PEs fragmented spontaneously below the spatial resolution of the γ-camera and, despite the high associated radioactivity, could not be localized in vivo. The fragmented clots were detectable by scintigraphy on excised lungs and provided excellent concordance with radiograms. Conclusion 99mTc-TP850 with its modest affinity (10−9 mol/L), rapid blood clearance, and high DVT and PE uptake is a promising agent for imaging vascular thrombosis. PMID:16391200

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

    SciTech Connect

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

    1991-01-01

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

  6. Characterization of TcCYC6 from Trypanosoma cruzi, a gene with homology to mitotic cyclins.

    PubMed

    Di Renzo, María Agostina; Laverrière, Marc; Schenkman, Sergio; Wehrendt, Diana Patricia; Tellez-Iñón, María Teresa; Potenza, Mariana

    2016-06-01

    Trypanosoma cruzi, the etiologic agent of Chagas disease, is a protozoan parasite with a life cycle that alternates between replicative and non-replicative forms, but the components and mechanisms that regulate its cell cycle are poorly described. In higher eukaryotes, cyclins are proteins that activate cyclin-dependent kinases (CDKs), by associating with them along the different stages of the cell cycle. These cyclin-CDK complexes exert their role as major modulators of the cell cycle by phosphorylating specific substrates. For the correct progression of the cell cycle, the mechanisms that regulate the activity of cyclins and their associated CDKs are diverse and must be controlled precisely. Different types of cyclins are involved in specific phases of the eukaryotic cell cycle, preferentially activating certain CDKs. In this work, we characterized TcCYC6, a putative coding sequence of T. cruzi which encodes a protein with homology to mitotic cyclins. The overexpression of this sequence, fused to a tag of nine amino acids from influenza virus hemagglutinin (TcCYC6-HA), showed to be detrimental for the proliferation of epimastigotes in axenic culture and affected the cell cycle progression. In silico analysis revealed an N-terminal segment similar to the consensus sequence of the destruction box, a hallmark for the degradation of several mitotic cyclins. We experimentally determined that the TcCYC6-HA turnover decreased in the presence of proteasome inhibitors, suggesting that TcCYC6 degradation occurs via ubiquitin-proteasome pathway. The results obtained in this study provide first evidence that TcCYC6 expression and degradation are finely regulated in T. cruzi. PMID:26709077

  7. Predictive role of miR-146a rs2910164 (C>G), miR-149 rs2292832 (T>C), miR-196a2 rs11614913 (T>C) and miR-499 rs3746444 (T>C) in the development of hepatocellular carcinoma

    PubMed Central

    Yan, Pingping; Xia, Miaojuan; Gao, Fei; Tang, Guanxiu; Zeng, Hui; Yang, Shuo; Zhou, Hongmei; Ding, Dan; Gong, Lina

    2015-01-01

    We conducted a case-control study to evaluate the association of miR-146a rs2910164 (C>G), miR-149 rs2292832 (T>C), miR-196a2 rs11614913 (T>C) and miR-499 rs3746444 (T>C) polymorphisms with the risk of hepatocellular carcinoma. A total of 274 patients with HCC were collected between January 2013 and December 2014. The polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was taken to determine the polymorphism of miR-146a C>G, miR-149 T>C, miR-196a2 T>C and miR-499 T>C. By comparing with control groups, patients with HCC were more likely to be males (OR=2.01, 95% CI=1.38-2.95), have older age (OR=1.52, 95% CI=1.09-2.13), have a history of alcohol drinking (OR=2.09, 95% CI=1.49-2.93), and be infected with HBV (OR=32.98, 95% CI=19.70-55.46) and HCV (OR=56.26, 95% CI=23.28-152.98) infection. By conditional regression analysis, individuals carrying the TC and CC genotypes of miR-196a2 T>C were found to be associated with an elevated risk of HCC compared to the TT genotype, and the adjusted odds ratio were 1.50 (1.03-2.17) and 2.86 (1.60-5.16), respectively. Moreover, the TC+CC genotype was correlated with an increased risk of HCC (OR=1.69, 95% CI=1.19-2.41) compared to the wide-type genotype. In conclusion, our results suggested that miR-196a2 T>C polymorphism is associated with HCC risk in Chinese population. PMID:26823863

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

    NASA Astrophysics Data System (ADS)

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

    2011-08-01

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

  9. 99mTc Labeled Glucagon-Like Peptide-1-Analogue (99mTc-GLP1) Scintigraphy in the Management of Patients with Occult Insulinoma

    PubMed Central

    Sowa-Staszczak, Anna; Trofimiuk-Müldner, Małgorzata; Stefańska, Agnieszka; Tomaszuk, Monika; Buziak-Bereza, Monika; Gilis-Januszewska, Aleksandra; Jabrocka-Hybel, Agata; Głowa, Bogusław; Małecki, Maciej; Bednarczuk, Tomasz; Kamiński, Grzegorz; Kowalska, Aldona; Mikołajczak, Renata; Janota, Barbara; Hubalewska-Dydejczyk, Alicja

    2016-01-01

    Introduction The aim of this study was to assess the utility of [Lys40(Ahx-HYNIC-99mTc/EDDA)NH2]-exendin-4 scintigraphy in the management of patients with hypoglycemia, particularly in the detection of occult insulinoma. Materials and Methods Forty patients with hypoglycemia and increased/confusing results of serum insulin and C-peptide concentration and negative/inconclusive results of other imaging examinations were enrolled in the study. In all patients GLP-1 receptor imaging was performed to localise potential pancreatic lesions. Results Positive results of GLP-1 scintigraphy were observed in 28 patients. In 18 patients postsurgical histopathological examination confirmed diagnosis of insulinoma. Two patients had contraindications to the surgery, one patient did not want to be operated. One patient, who presented with postprandial hypoglycemia, with positive result of GLP-1 imaging was not qualified for surgery and is in the observational group. Eight patients were lost for follow up, among them 6 patients with positive GLP-1 scintigraphy result. One patient with negative scintigraphy was diagnosed with malignant insulinoma. In two patients with negative scintigraphy Munchausen syndrome was diagnosed (patients were taking insulin). Other seven patients with negative results of 99mTcGLP-1 scintigraphy and postprandial hypoglycemia with C-peptide and insulin levels within the limits of normal ranges are in the observational group. We would like to mention that 99mTc-GLP1-SPECT/CT was also performed in 3 pts with nesidioblastosis (revealing diffuse tracer uptake in two and a focal lesion in one case) and in two patients with malignant insulinoma (with the a focal uptake in the localization of a removed pancreatic headin one case and negative GLP-1 1 scintigraphy in the other patient). Conclusions 99mTc-GLP1-SPECT/CT could be helpful examination in the management of patients with hypoglycemia enabling proper localization of the pancreatic lesion and effective

  10. Environmental applications of XANES: Speciation of {Tc} in cement after chemical treatment and Se after bacterial uptake

    SciTech Connect

    Shuh, D.K.; Kaltsoyannis, N.; Bucher, J.J.

    1994-03-01

    XANES (X-ray Absorption Near Edge Spectroscopy) has been employed to evaluate the efficacy of a process designed to encapsulate and reduce {Tc}O{sub 4}{sup {minus}} in cement matrices, thereby immobilizing {Tc}. The oxidation state of Se following.bioremediation of Se by bacteria has also been determined by XANES. The XANES measurements were performed at the Stanford Synchrotron Radiation Laboratory (SSRL) and the National Synchrotron Light Source (NSLS) at the respective K edges of {Tc} (21.0 keV) and Se (12.7 keV). Comparison of the XANES spectra of Tc in untreated cement to Tc in slag treated cement and to the chemical shifts of reference materials, shows that the oxidation state of {Tc} is the same in both cements. Thus, the addition of a reducing agent to the cement formulation does not significantly reduce the {Tc}O{sub 4} The common soil bacterium, Bacillus subtilis, is known to incorporate Se on or within the cell wall when exposed to a SE(IV) solution. The Se XANES spectra of B. subtilis, as well as bacillus isolated from selenium rich soil, show that the organisms reduce selenite to the red allotrope of elemental Se.

  11. [Diagnosis of inflammatory myopathy; usefulness of 99mTc MDP scintigraphy and muscle MRI for determination of affected sites].

    PubMed

    Nakayama, T; Saitoh, Y; Yatabe, K; Sueishi, M; Kawai, M

    1999-11-01

    We studied the effectiveness of 99mTc-MDP (methylendiphosphate) scintigraphy in imaging inflammatory myopathy. The three subjects including 1 male and 2 female patients had high creatine kinase (CK) levels and proximal dominant muscle weakness. In whole body muscle surveillance by 99mTc-MDP scintigraphy, abnormal 99mTc-MDP accumulation was found in the extremities of all patients. The sites with high 99mTc-MDP accumulation showed high intensity on T2 weighted MR imaging, suggesting an inflammatory process. Muscle biopsy was performed on two patients from the muscles with the abnormal MRI findings, which showed the diagnostic finding of inflammatory changes. Because muscle involvement in inflammatory myopathy differs from muscle to muscle, it is sometimes difficult to choose appropriate muscle biopsy sites for diagnostic purposes. Affected muscles are more easily identified by using 99mTc-MDP muscle scintigraphy and muscle MRI, therefore, a correct diagnosis and choice of biopsy site can be made. 99mTc-PYP scintigraphy is permitted for use in myocardial infarction alone and 111In-antimyosin scintigraphy is not available in Japan. Therefore, we recommend 99mTc-MDP scintigraphy for diagnosis of inflammatory myopathy and for determination of muscle biopsy sites. PMID:10689932

  12. Chondro-Protective and Antiarthritic Effects of Sulfonamido-Based Gallate-ZXHA-TC in Vitro and in Vivo.

    PubMed

    Lu, Zhenhui; Wu, Huayu; Lin, Xiao; Liu, Buming; Lin, Cuiwu; Zheng, Li; Zhao, Jinmin

    2016-06-17

    The effects of gallic acid (GA) on arthritis are limited by weak antioxidant effects and inferior biological properties of GA. We recently described a new series of synthesized GA derivatives by coupling with sulfonamides. Among these analogs, a novel compound synthesized from GA and sulfadimoxine (SDM) named ZXHA-TC exhibited the most robust anti-inflammatory potential. In this current study, the chondro-protective and antiarthritic effects of ZXHA-TC were investigated both in vitro and in vivo. In the in vitro study, ZXHA-TC exerted chondro-protective effects as evidenced by promoting cell proliferation and the maintaining of the phenotype of articular chondrocytes treated with interleukin-1-beta (IL-1β). The potential of ZXHA-TC to slow the progress of osteoarthritis (OA) was suggested by a reduction in matrix metalloproteinases (MMPs) and the up-regulation of the tissue inhibitor of metalloproteinase-1 (TIMP-1). In a rabbit anterior cruciate ligament transaction (ACLT) model of OA, ZXHA-TC exerted a protective effect on arthritis as assessed by macroscopic scores, histological, qRT-PCR, and immunohistochemical analyses. The effects of ZXHA-TC on inhibiting the production of inflammatory mediators in OA may be mediated partly by the suppression of the PI3K/AKT pathway or MAPK cascades, leading to NF-κB inactivation. Thus, this study indicates that ZXHA-TC may be developed as a potential therapeutic agent for OA. PMID:27017891

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

    PubMed Central

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

    2013-01-01

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

  14. The Chromosome-Encoded Hypothetical Protein TC0668 Is an Upper Genital Tract Pathogenicity Factor of Chlamydia muridarum

    PubMed Central

    Conrad, Turner Allen; Gong, Siqi; Yang, Zhangsheng; Matulich, Patrick; Keck, Jonathon; Beltrami, Noah; Chen, Chaoqun; Zhou, Zhou; Dai, Jin

    2015-01-01

    We previously associated a missense mutation of the tc0668 gene of serial in vitro-passaged Chlamydia muridarum, a murine model of human urogenital C. trachomatis, with severely attenuated disease development in the upper genital tract of female mice. Since these mutants also contained a TC0237 Q117E missense mutation that enhances their in vitro infectivity, an effort was made here to isolate and characterize a tc0668 single mutant to determine its individual contribution to urogenital pathogenicity. Detailed genetic analysis of C. muridarum passages revealed a truncated variant with a G216* nonsense mutation of the 408-amino-acid TC0668 protein that does not produce a detectable product. Intracellular growth and infectivity of C. muridarum in vitro remain unaffected in the absence of TC0668. Intravaginal inoculation of the TC0668 null mutant into C3H/HeJ mice results in a typical course of lower genital tract infection but, unlike a pathogenic isogenic control, is unable to elicit significant chronic inflammation of the oviduct and fails to induce hydrosalpinx. Thus, TC0668 is demonstrated as an important chromosome-encoded urogenital pathogenicity factor of C. muridarum and the first with these characteristics to be discovered for a Chlamydia pathogen. PMID:26597987

  15. Products of pertechnetate radiolysis in highly alkaline solution: structure of TcO2 x xH2O.

    PubMed

    Lukens, Wayne W; Bucher, Jerome I; Edelstein, Norman M; Shuh, David K

    2002-03-01

    The chemistry of technetium in certain high-level nuclear waste (HLW) tanks at the Hanford Site complicates the treatment and vitrification of HLW. A major problem is the presence, in certain tanks, of unidentified, lower-valent technetium species, which are difficult to remove from the waste by current separation processes. Radiolytic reduction of TcO4- in alkaline solutions containing selected organic compounds, approximating the conditions in HLW, was investigated to determine the classes of compounds that can be formed under these conditions. Insoluble TcO2 x xH2O is the primary radiolysis product with the majority of organic compounds investigated, including citrate, dibutyl phosphate, and aminopolycarboxylates. X-ray absorption fine structure (XAFS) measurements show that TcO2 x xH2O has a one-dimensional chain structure consisting of edge-sharing TcO6 octahedra with bridging oxide and trans water ligands. When diols, such as ethylene glycol, are present, only soluble, Tc(IV) alkoxide compounds are produced. The XAFS and UV-visible spectra of these compounds provide evidence for a binuclear structure similar to (H2EDTA)2Tc2(mu-O)2. The properties of the Tc(IV) alkoxide complexes were determined and are consistent with those observed for the soluble, lower-valent technetium complexes that complicate the treatment of HLW at the Hanford site. PMID:11918000

  16. Tribolium castaneum RR-1 cuticular protein TcCPR4 is required for formation of pore canals in rigid cuticle.

    PubMed

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

    2015-02-01

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

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

    PubMed Central

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

    2015-01-01

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

  18. Knockdown of TC-1 enhances radiosensitivity of non-small cell lung cancer via the Wnt/β-catenin pathway

    PubMed Central

    Wu, Dapeng; Li, Lei; Yan, Wei

    2016-01-01

    ABSTRACT Thyroid cancer 1 (TC-1, C8ofr4) is widely expressed in vertebrates and associated with many kinds of tumors. Previous studies indicated that TC-1 functions as a positive regulator in the Wnt/β-catenin signaling pathway in non-small cell lung cancer (NSCLC). However, its exact role and regulation mechanism in radiosensitivity of NSCLC are still unclear. The expression level of TC-1 was measured by qRT-PCR and western blot in NSCLC cell lines. Proliferation and apoptosis of NSCLC cells in response to TC-1 knockdown or/and radiation were determined by MTT assay and flow cytometry, respectively. The activation of the Wnt/β-catenin signaling pathway was further examined by western blot in vitro and in vivo. Compared to TC-1 siRNA or radiotherapy alone, TC-1 silencing combined with radiation inhibited cell proliferation and induced apoptosis in NSCLC cell lines by inactivating of the Wnt/β-catenin signaling pathway. Furthermore, inhibition of the Wnt/β-catenin signaling pathway by XAV939, a Wnt/β-catenin signaling inhibitor, contributed to proliferation inhibition and apoptosis induction in NSCLC A549 cells. Combinative treatment of A549 xenografts with TC-1 siRNA and radiation caused significant tumor regression and inactivation of the Wnt/β-catenin signaling pathway relative to TC-1 siRNA or radiotherapy alone. The results from in vitro and in vivo studies indicated that TC-1 silencing sensitized NSCLC cell lines to radiotherapy through the Wnt/β-catenin signaling pathway. PMID:27029901

  19. TC-1734: an orally active neuronal nicotinic acetylcholine receptor modulator with antidepressant, neuroprotective and long-lasting cognitive effects.

    PubMed

    Gatto, Gregory J; Bohme, G Andrees; Caldwell, William S; Letchworth, Sharon R; Traina, Vincent M; Obinu, M Carmen; Laville, Michel; Reibaud, Michel; Pradier, Laurent; Dunbar, Geoffrey; Bencherif, Merouane

    2004-01-01

    The development of selective ligands targeting neuronal nicotinic acetylcholine receptors to alleviate symptoms associated with neurodegenerative diseases presents the advantage of affecting multiple deficits that are the hallmarks of these pathologies. TC-1734 is an orally active novel neuronal nicotinic agonist with high selectivity for neuronal nicotinic receptors. Microdialysis studies indicate that TC-1734 enhances the release of acetylcholine from the cortex. TC-1734, by either acute or repeated administration, exhibits memory enhancing properties in rats and mice and is neuroprotective following excitotoxic insult in fetal rat brain in cultures and against alterations of synaptic transmission induced by deprivation of glucose and oxygen in hippocampal slices. At submaximal doses, TC-1734 produced additive cognitive effects when used in combination with tacrine or donepezil. Unlike (-)-nicotine, behavioral sensitization does not develop following repeated administration of TC-1734. Its pharmacokinetic (PK) profile (half-life of 2 h) contrasts with the long lasting improvement in working memory (18 h) demonstrating that cognitive improvement extends beyond the lifetime of the compound. The very low acute toxicity of TC-1734 and its receptor activity profile provides additional mechanistic basis for its suggested potential as a clinical candidate. TC-1734 was very well tolerated in acute and chronic oral toxicity studies in mice, rats and dogs. Phase I clinical trials demonstrated TC-1734's favorable pharmacokinetic and safety profile by acute oral administration at doses ranging from 2 to 320 mg. The bioavailability, pharmacological, pharmacokinetic, and safety profile of TC-1734 provides an example of a safe, potent and efficacious neuronal nicotinic modulator that holds promise for the management of the hallmark symptomatologies observed in dementia. PMID:15179444

  20. Knockdown of TC-1 enhances radiosensitivity of non-small cell lung cancer via the Wnt/β-catenin pathway.

    PubMed

    Wu, Dapeng; Li, Lei; Yan, Wei

    2016-01-01

    Thyroid cancer 1 (TC-1, C8ofr4) is widely expressed in vertebrates and associated with many kinds of tumors. Previous studies indicated that TC-1 functions as a positive regulator in the Wnt/β-catenin signaling pathway in non-small cell lung cancer (NSCLC). However, its exact role and regulation mechanism in radiosensitivity of NSCLC are still unclear. The expression level of TC-1 was measured by qRT-PCR and western blot in NSCLC cell lines. Proliferation and apoptosis of NSCLC cells in response to TC-1 knockdown or/and radiation were determined by MTT assay and flow cytometry, respectively. The activation of the Wnt/β-catenin signaling pathway was further examined by western blotin vitroandin vivo Compared to TC-1 siRNA or radiotherapy alone, TC-1 silencing combined with radiation inhibited cell proliferation and induced apoptosis in NSCLC cell lines by inactivating of the Wnt/β-catenin signaling pathway. Furthermore, inhibition of the Wnt/β-catenin signaling pathway by XAV939, a Wnt/β-catenin signaling inhibitor, contributed to proliferation inhibition and apoptosis induction in NSCLC A549 cells. Combinative treatment of A549 xenografts with TC-1 siRNA and radiation caused significant tumor regression and inactivation of the Wnt/β-catenin signaling pathway relative to TC-1 siRNA or radiotherapy alone. The results fromin vitroandin vivostudies indicated that TC-1 silencing sensitized NSCLC cell lines to radiotherapy through the Wnt/β-catenin signaling pathway. PMID:27029901

  1. 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 μM 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 α-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

  2. Reduction of TcO4- by sediment-associated biogenic Fe(II)

    SciTech Connect

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

    2004-08-01

    The potential for reduction of {sup 99}TcO{sub 4}{sup -}{sub aq} to poorly soluble {sup 99}TcO{sub 2} {center_dot} nH{sub 2}O{sub (s)} by biogenic sediment-associated Fe(II) was investigated with three Fe(III)-oxide containing subsurface materials and the dissimilatory metal-reducing subsurface bacterium Shewanella putrefaciens CN32. Two of the subsurface materials from the U.S. Department of Energy's Hanford and Oak Ridge sites contained significant amounts of Mn(III,IV) oxides and net bioreduction of Fe(III) to Fe(II) was not observed until essentially all of the hydroxylamine HCl-extractable Mn was reduced. In anoxic, unreduced sediment or where Mn oxide bioreduction was incomplete, exogenous biogenic TcO{sub 2} {center_dot} nH{sub 2}O{sub (s)} was slowly oxidized over a period of weeks. Subsurface materials that were bioreduced to varying degrees and then pasteurized to eliminate biological activity, reduced TcO{sub 4}{sup -}{sub (aq)} at rates that generally increased with increasing concentrations of 0.5 N HCl-extractable Fe(II). Two of the sediments showed a common relationship between extractable Fe(II) concentration (in mM) and the first-order reduction rate (in h{sup -1}), whereas the third demonstrated a markedly different trend. A combination of chemical extractions and {sup 57}Fe Moessbauer spectroscopy were used to characterize the Fe(III) and Fe(II) phases. There was little evidence of the formation of secondary Fe(II) biominerals as a result of bioreduction, suggesting that the reactive forms of Fe(II) were predominantly surface complexes of different forms. The reduction rates of Tc(VII)O{sub 4}{sup -} were slowest in the sediment that contained plentiful layer silicates (illite, vermiculite, and smectite), suggesting that Fe(II) sorption complexes on these phases were least reactive toward pertechnetate. These results suggest that the in situ microbial reduction of sediment-associated Fe(III), either naturally or via redox manipulation, may be

  3. Reduction of TcO 4- by sediment-associated biogenic Fe(II)

    NASA Astrophysics Data System (ADS)

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

    2004-08-01

    The potential for reduction of 99TcO 4-(aq) to poorly soluble 99TcO 2 · nH 2O (s) by biogenic sediment-associated Fe(II) was investigated with three Fe(III)-oxide containing subsurface materials and the dissimilatory metal-reducing subsurface bacterium Shewanella putrefaciens CN32. Two of the subsurface materials from the U.S. Department of Energy's Hanford and Oak Ridge sites contained significant amounts of Mn(III,IV) oxides and net bioreduction of Fe(III) to Fe(II) was not observed until essentially all of the hydroxylamine HCl-extractable Mn was reduced. In anoxic, unreduced sediment or where Mn oxide bioreduction was incomplete, exogenous biogenic TcO 2 · nH 2O (s) was slowly oxidized over a period of weeks. Subsurface materials that were bioreduced to varying degrees and then pasteurized to eliminate biological activity, reduced TcO 4-(aq) at rates that generally increased with increasing concentrations of 0.5 N HCl-extractable Fe(II). Two of the sediments showed a common relationship between extractable Fe(II) concentration (in mM) and the first-order reduction rate (in h -1), whereas the third demonstrated a markedly different trend. A combination of chemical extractions and 57Fe Mössbauer spectroscopy were used to characterize the Fe(III) and Fe(II) phases. There was little evidence of the formation of secondary Fe(II) biominerals as a result of bioreduction, suggesting that the reactive forms of Fe(II) were predominantly surface complexes of different forms. The reduction rates of Tc(VII)O 4- were slowest in the sediment that contained plentiful layer silicates (illite, vermiculite, and smectite), suggesting that Fe(II) sorption complexes on these phases were least reactive toward pertechnetate. These results suggest that the in situ microbial reduction of sediment-associated Fe(III), either naturally or via redox manipulation, may be effective at immobilizing TcO 4-(aq) associated with groundwater contaminant plumes.

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

    PubMed

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

    2009-07-01

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

  5. Separation of [(99m)Tc]pertechnetate and molybdate using polyethylene glycol coated C18 and C30 resins.

    PubMed

    Andersson, J D; Wilson, J S; Romaniuk, J A; McEwan, A J B; Abrams, D N; McQuarrie, S A; Gagnon, K

    2016-04-01

    Hydrophobic adsorbents such as C18 and C30 were coated with PEG and subsequently used for the separation of Mo/Tc. The most effective resin for adsorbing PEG was the C18-U resin, which demonstrated a coating capacity of 97.6±2.8mg PEG per g of resin. The ability to adsorb pertechnetate was proportional to the amount of PEG coated on the hydrophobic resin. The [(99m)Tc]pertechnetate recovery during the separation of cyclotron produced (99m)Tc from (100)Mo was 91.8±0.3% (n=2). The resultant product met relevant USP monograph specifications. PMID:26829618

  6. Quantum-limit linkage of ‘strange’ and conventional metal states of high-Tc superconductors

    NASA Astrophysics Data System (ADS)

    Krusin-Elbaum, L.; Shibauchi, T.; Kasahara, Y.; Okazaki, R.; Matsuda, Y.; McDonald, R. D.; Mielke, C. H.; Hasegawa, M.

    2013-10-01

    The key to the nature of superconducting pairing in high-Tc cuprates lies in understanding the transition to a conventional behavior when they are heavily doped. By using high magnetic fields, we show that the pseudogapped Tl2Ba2CuO6+x becomes a conventional metal at heavy doping in a quantum phase transition, where the pseudogap boundary develops a thermodynamic divergence corresponding to a zero entropy jump. The critical doping point downshifts with magnetic field in unison with the suppression of Tc. This implies that quantum critical fluctuations and magnetic degrees that destabilize the pseudogap are linked to the superconductivity with high Tc.

  7. Application of AnaLig resin for (99m)Tc separation from (100)Mo target irradiated in cyclotron.

    PubMed

    Pawlak, D W; Wojdowska, W; Parus, L J; Mikołajczak, R

    2016-07-01

    The purpose of this study was the development of procedure for molybdenum metallic target processing after its irradiation in a cyclotron. As a first step the dissolution of molybdenum in various physical forms was investigated. The concentrations of NaOH and (NH4)2CO3 allowing the highest sorption of Tc on AnaLig Tc-02 resin had been found. Based on these results the sintered irradiated Mo pellet was processed. The radionuclidic and radiochemical purities of separated Tc product were evaluated. PMID:27149397

  8. High 99mTc-DPD myocardial uptake in a patient with apolipoprotein AI-related amyloidotic cardiomyopathy.

    PubMed

    Quarta, Candida Cristina; Obici, Laura; Guidalotti, Pier Luigi; Pieroni, Maurizio; Longhi, Simone; Perlini, Stefano; Verga, Laura; Merlini, Giampaolo; Rapezzi, Claudio

    2013-03-01

    Amyloidotic cardiomyopathy is still a widely underdiagnosed condition that usually requires endomyocardial biopsy (EMB) for a definite diagnosis. 99mTc-3,3-diphosphono-1,2-propanodicarboxylic acid (99mTc-DPD) has proven highly sensitive for detecting amyloidotic cardiomyopathy due to transthyretin-related amyloid deposition. Herein we report the first description of the (99mTc-DPD scintigraphy profile in a patient with suspected amyloidotic cardiomyopathy and a final EMB- and genetically-proven diagnosis of familial apolipoprotein AI amyloidosis due to Leu174Ser variant. PMID:23231421

  9. Phase stability, electronic structure and equation of state of cubic TcN from first-principles calculations

    NASA Astrophysics Data System (ADS)

    Song, T.; Ma, Q.; Sun, X. W.; Liu, Z. J.; Fu, Z. J.; Wei, X. P.; Wang, T.; Tian, J. H.

    2016-09-01

    The phase transition, electronic band structure, and equation of state (EOS) of cubic TcN are investigated by first-principles pseudopotential method based on density-functional theory. The calculated enthalpies show that TcN has a transformation between zincblende and rocksalt phases and the pressure determined by the relative enthalpy is 32 GPa. The calculated band structure indicates the metallic feature and it might make cubic TcN a better candidate for hard materials. Particular attention is paid to the predictions of volume, bulk modulus and its pressure derivative which play a central role in the formulation of approximate EOSs using the quasi-harmonic Debye model.

  10. Radionuclide venography: two stage--flow and equilibrium technique using 99mTc pertechnetate, and 99mTc RBC labelled "in vivo".

    PubMed

    Snarski, A M

    1989-01-01

    A new method involves 2 stages: 1st, injection of three 10 ml boluses of 99mTc-pertechnetate through a dorsal vein of the foot with recording of 3 separate dynamic studies of venous flow in the calf, thigh and pelvis; and 2nd, static equilibrium venography (EV), which can be completed 15 min later after 99mTc-RBC labelling in vivo. The method was performed in 100 patients with suspected DVT. Due to the large pertechnetate bolus followed with 20-40 ml flush of normal saline, the flow study provides a significant improvement in filling of major calf veins, which makes this technique more similar to contrast phlebography. The flow study was found much more sensitive than EV, especially for calf DVT. However, EV, providing information about the unaffected leg, plays an important complementary role when the study is negative for DVT. In conclusion, both stages are recommended for routine examination of patients referred with suspected DVT. PMID:2540983

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

    PubMed Central

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

    2014-01-01

    Trypanosoma cruzi infection may be caused by different strains with distinct discrete typing units (DTUs) that can result in variable clinical forms of chronic Chagas disease. The present study evaluates the immune response and cardiac lesions in dogs experimentally infected with different T. cruzi strains with distinct DTUs, namely, the Colombian (Col) and Y strains of TcI and TcII DTU, respectively. During infection with the Col strain, increased levels of alanine aminotransferase, erythrocytes, haematocrit and haemoglobin were observed. In addition, CD8+ T-lymphocytes isolated from the peripheral blood produced higher levels of interleukin (IL)-4. The latter suggests that during the acute phase, infection with the Col strain may remain unnoticed by circulating mononuclear cells. In the chronic phase, a significant increase in the number of inflammatory cells was detected in the right atrium. Conversely, infection with the Y strain led to leucopoenia, thrombopoenia, inversion of the ratio of CD4+/CD8+ T-lymphocytes and alterations in monocyte number. The Y strain stimulated the production of interferon-γ by CD4+ and CD8+ T-lymphocytes and IL-4 by CD8+ T-cells. In the chronic phase, significant heart inflammation and fibrosis were observed, demonstrating that strains of different DTUs interact differently with the host. PMID:25591108

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

    NASA Astrophysics Data System (ADS)

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

    2015-11-01

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

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

    PubMed

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

    2015-11-01

    Cyclotron production of 99mTc through the (100)Mo(p,2n)99mTc reaction channel is actively being investigated as an alternative to reactor-based (99)Mo generation by nuclear fission of (235)U. Like most radioisotope production methods, cyclotron production of 99mTc will result in creation of unwanted impurities, including Tc and non-Tc isotopes. It is important to measure the amounts of these impurities for release of cyclotron-produced 99mTc (CPTc) for clinical use. Detection of radioactive impurities will rely on measurements of their gamma (γ) emissions. Gamma spectroscopy is not suitable for this purpose because the overwhelming presence of 99mTc and the count-rate limitations of γ spectroscopy systems preclude fast and accurate measurement of small amounts of impurities. In this article we describe a simple and fast method for measuring γ emission rates from radioactive impurities in CPTc. The proposed method is similar to that used to identify (99)Mo breakthrough in generator-produced 99mTc: one dose calibrator (DC) reading of a CPTc source placed in a lead shield is followed by a second reading of the same source in air. Our experimental and theoretical analysis show that the ratio of DC readings in lead to those in air are linearly related to γ emission rates from impurities per MBq of 99mTc over a large range of clinically-relevant production conditions. We show that estimates of the γ emission rates from Tc impurities per MBq of 99mTc can be used to estimate increases in radiation dose (relative to pure 99mTc) to patients injected with CPTc-based radiopharmaceuticals. This enables establishing dosimetry-based clinical-release criteria that can be tested using commercially-available dose calibrators. We show that our approach is highly sensitive to the presence of 93gTc, 93mTc, 94gTc, 94mTc, 95mTc, 95gTc, and 96gTc, in addition to a number of non-Tc impurities. PMID:26449791

  14. Spin-polaron theory of high-{Tc} superconductivity: 3, Gap function and critical temperature

    SciTech Connect

    Wood, R.F.

    1993-06-01

    Results from previous papers in this series are used to derive approximate expressions for the gap and {Tc} within the framework of a Cooper-pairing approach. The possible symmetry types of the gap are discussed. It is shown how the proximity of the Fermi level to the Mott-Hubbard band edge and the interplay of O 2p{sigma} and 2p{pi} bands and/or localization effects can provide good fits to the variation of {Tc} with x in La{sub 2-x}Sr{sub x}CuO{sub 4} and YBa{sub 2}Cu{sub 3}O{sub 7-x}. It is concluded that the in-plane gap is either s- or d-like but anisotropic in either case. Other aspects and implications of the model and of the calculations are given and comparisons with Mott`s spin-bipolaron model are made.

  15. Transfer of /sup 131/I and /sup 95m/Tc from pasture to goat milk

    SciTech Connect

    Bondietti, E.A.; Garten, C.T. Jr.

    1984-01-01

    Field measurements were made in 1983 on the transfer of /sup 131/I and /sup 95m/Tc from spray-contaminated pasture to goat's milk. The transfer of /sup 131/I to milk was similar to that used for mathematical models in US Nuclear Regulatory Commission Regulatory Guide 1.109, which was derived from stall-feeding experiments using capsulized doses. Compared to /sup 131/I, the /sup 95m/Tc transferred to milk was about 5600 times less. The lower transfer resulted from both immobilization of technetium on pasture prior to ingestion as well as reduced gastrointestinal absorption. The results show that the food chain transfer of technetium to milk is much less than that previously expected based on inferences made from metabolism studies. 6 references, 4 figures, 1 table.

  16. Flux Creep and Giant Flux Creep in High Tc Hg,Pb-based Superconductors

    NASA Astrophysics Data System (ADS)

    Kirven, Douglas; Owens, Frank; Iqbal, Z.; Bleiweiss, M.; Lungu, A.; Datta, T.

    1996-03-01

    Dynamic behavior of the trapped flux in fields of up to 17.5 T was studied in a set of Hg-Pb based superconductors with a Tc in excess of 130 K. Depending on the experimental conditions, both creep and giant flux creep dynamics were observed. Results were analyzed using to standard models such as Anderson-Kim and giant-flux creep models (GFC). The plots of relaxation rate of remnant magnetization versus temperature show a peak below Tc. These results were compared with other Cu-O compounds. A distribution of activation energies was found from the magnetization rate. The activation energy distribution shows a peak around 50 K. The peak determines the temperature where the flux flow rate is a maximum. A universal relation of the resistive behavior was also found as a function of temperature and field. The zero-field/field-cooled results gave a reversibility curve that also obeyed a universal power relation.

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

    SciTech Connect

    Zhang, Z.M.

    1996-12-31

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

  18. Investigation of low-energy electronic response in high-{Tc} superconductor by Raman spectroscopy

    SciTech Connect

    Yamanaka, Akio; Asayama, Nobuo; Furutani, Takashi; Inoue, Kuon; Takekawa, Shunji

    1996-12-31

    Low-energy electronic response due to single-particle excitations has been investigated in high-{Tc} copper-oxide Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+{delta}} single-crystals by Raman scattering spectroscopy. The authors find that the low-energy electronic response in the superconducting phase depends significantly on polarization configuration. For tetragonal B{sub 1g} the suppression of the low-energy spectral weight of the electronic continuum due to an opening of the superconducting gap occurs abruptly below {Tc}, whereas that of the B{sub 2g}-response shows a gradual temperature dependence. The symmetry-dependent superconducting response is basically consistent with the superconducting order parameter having a nodal structure with X{sup 2}-Y{sup 2} symmetry.

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

    PubMed Central

    Cınar, Alev; Sadıc, Murat; Demırel, Koray; Korkmaz, Meliha

    2013-01-01

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

  20. Hepatobiliary scanning with 99mTc-PIPIDA in acute cholecystitis

    SciTech Connect

    Mauro, M.A.; McCartney, W.H.; Melmed, J.R.

    1982-01-01

    Ninety-five patients with clinically suspected acute cholecystitis underwent hepatobiliary scanning with 99mTc-PIPIDA. A positive scan (nonvisualization of the gallbladder with visualization of the common bile duct and gut) was found in 29 patients; 25 of them (86%) had surgically proven acute cholecystitis and 4 (14%) had chronic cholecystitis. Five of the 25 with acute cholecystitis had acalculous disease. A negative examination (gallbladder visualization) occurred in 63 patients; 18 (29%) had chronic cholecystitis and 45 (71%) were subsequently found to have nonbiliary disease. Three indeterminate studies (nonvisualization of both the gallbladder and gut) were obtained in patients with choledocholithiasis and chronic cholecystitis. In the evaluation of acute cholecystitis, the 99mTc-PIPIDA hepatobiliary scan was 100% sensitive and 94% specific.