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Sample records for gadolinium calcium oxoborate

  1. Electronic structure of lanthanum calcium oxoborate LaCa4O(BO3)3

    International Nuclear Information System (INIS)

    Nelson, A.J.; Buuren, T. van; Willey, Trevor M.; Bostedt, C.; Adams, J.J.; Schaffers, K.I.; Terminello, Lou; Callcott, T.A.

    2004-01-01

    Lanthanum calcium oxoborate (LaCOB) is a nonlinear optical (NLO) material that belongs to the calcium-rare-earth (R) oxoborate family, with general composition Ca 4 RO(BO 3 ) 3 (R 3+ =La, Sm, Gd, Lu, Y). X-ray photoemission, photoabsorption, and resonant fluorescence were applied to study the electronic structure of this material. High resolution photoemission measurements on the valence band (VB) electronic structure and La 3d and 4d, Ca 2p, B 1s, and O 1s core lines were used to evaluate the surface and near surface chemistry. Element specific density of unoccupied electronic states in LaCOB were probed by X-ray absorption spectroscopy (XAS) at the La 3d (M 4,5 -edge), B 1s, and O 1s (K-edges) absorption edges. Soft X-ray fluorescence was used to further examine valence band states associated with spectral differences noted in the absorption measurements. These results provide the first measurements of the electronic structure and surface chemistry of this rare-earth oxoborate

  2. Physical and chemical properties of calcium doped gadolinium cobaltite

    International Nuclear Information System (INIS)

    Zhuk, P.P.; Kharton, V.V.; Tonoyan, A.A.; Naumovich, E.N.

    1991-01-01

    The effect of calcium doping additions on electrical and tharmal properties of gadolinium cobaltite was investigated. It was established that solid solutions of Gd 1-x Ca x CoO 3 (x=0-0.5) composition had cubic perovskite structure with orthorhombic distortion. Calcium doping of gadolinium cobaltite increases its conductivity by two orders. Parameter of resistance of electronic layer of ρ/d for a sample of Gd 0.9 Ca 0.1 CoO 3 composition at d≥40mg/sm 2 was by an order higher than in compact samples

  3. Linear optical properties of Ca4EuO(BO3)3 and Eu3+ : Ca4GdO(BO3)3 crystals

    International Nuclear Information System (INIS)

    Antic-Fidancev, E.; Lemaitre-Blaise, M.; Porcher, P.; Caramanian, A.; Aka, G.

    1998-01-01

    Full text: The title compounds are now intensively studied due to their quadratic nonlinear properties in view of applications, e.g. high power laser frequency conversion. Rare earth calcium oxoborates, Ca 4 REO(BO 3 ) 3 , constitute an isostructural family along the rare earth series with RE = La - Lu, Y included. These compounds crystallize in the monoclinic biaxial crystal system with Cm (N 8) space group. They are isostructural to the calcium fluoroborate Ca 5 (BO 3 ) 3 F which is related to the fluoroapatite structure Ca 5 (PO 4 ) 3 F. The rare earth ions are located in the distorted octahedron with C s point site symmetry in the mirror plane. Two types of distorted octahedral sites exist for calcium ions. The existence of some disorder between calcium and rare earth atoms is suspected from the structural analysis. Good optical quality crystals of europium (or gadolinium) oxoborate, EuCOB (GdCOB) have been grown from the stoichiometric melt by the Czochralski pulling method. From the luminescence of the Eu 3+ doped gadolinium or in the europium stoichiometric compound very complex emission spectra have been obtained. It principally depends on the preparation method of studied samples: i) for a monocrystalline sample, a single phase with a single site is observed; ii) for a polycrystalline sample complex feature occurs. It is probably due to an expanded disorder between calcium and rare earth atoms. Practically, there is one principal site corresponding to the low symmetry site of the rare earth as expected from the structural investigation. Other minor sites are attributed to the local distortion created around the active rare earth ion. The intensity of the emission lines of Eu 3+ used as a local structural probe related to these minor sites increases when the gadolinium in Ca 4 GdO(BO 0 ) 3 is substituted by lanthanum or yttrium ions. It seems therefore evident that the synthesis of these rare earth calcium oxoborates must be realised carefully. The crystal

  4. Investigation of gadolinium (3)-, calcium (2)- and copper (2) complexes with riboflavin in acetonitrile

    International Nuclear Information System (INIS)

    Lugina, L.N.

    1984-01-01

    Electron and IR spectra of gadolinium-(3), calcium (2), and copper (2) complexes with riboflavin (RF) in acetopitrile against the background of LiClO 4 x3H 2 O are studied. The way of RF coordination by the atom of metal is shown to depend on the nature of metal. Gadolinium (3) coordinates RF through N and O atoms; copper - through O metal, calcium - through O atom and, evidently, through hydroxyl groups of ribitol. Directions of RF line shifts of π-π * electron transitions at RF complexing with metals are compared with the calculated results and directions of RF line shifts during the formation of hydrogen bonds with different donor atoms of the isoalloxazine ring

  5. Neuroprotective effect of gadolinium: a stretch-activated calcium channel blocker in mouse model of ischemia-reperfusion injury.

    Science.gov (United States)

    Gulati, Puja; Muthuraman, Arunachalam; Jaggi, Amteshwar S; Singh, Nirmal

    2013-03-01

    The present study was designed to investigate the potential of gadolinium, a stretch-activated calcium channel blocker in ischemic reperfusion (I/R)-induced brain injury in mice. Bilateral carotid artery occlusion of 12 min followed by reperfusion for 24 h was given to induce cerebral injury in male Swiss mice. Cerebral infarct size was measured using triphenyltetrazolium chloride staining. Memory was assessed using Morris water maze test and motor incoordination was evaluated using rota-rod, lateral push, and inclined beam walking tests. In addition, total calcium, thiobarbituric acid reactive substance (TBARS), reduced glutathione (GSH), and acetylcholinesterase (AChE) activity were also estimated in brain tissue. I/R injury produced a significant increase in cerebral infarct size. A significant loss of memory along with impairment of motor performance was also noted. Furthermore, I/R injury also produced a significant increase in levels of TBARS, total calcium, AChE activity, and a decrease in GSH levels. Pretreatment of gadolinium significantly attenuated I/R-induced infarct size, behavioral and biochemical changes. On the basis of the present findings, we can suggest that opening of stretch-activated calcium channel may play a critical role in ischemic reperfusion-induced brain injury and that gadolinium has neuroprotective potential in I/R-induced injury.

  6. Luminescence properties of Ce3+ doped gadolinium-calcium-silicaborate glass scintillator

    International Nuclear Information System (INIS)

    Park, J.M.; Ha, D.H.; Kaewjeang, S.; Maghanemi, U.; Kothan, S.; Kaewkhao, J.; Kim, H.J.

    2016-01-01

    In this work, the Ce 3+ doped gadolinium-calcium-silicaborate glass scintillators of the composition ratio 25Gd 2 O 3 :10CaO:10SiO 2 :(55−x)B 2 O 3 :xCeF 3 , have been fabricated by using the melt-quenching technique. The doping concentration of the Ce 3+ was varied from 0.05 mol% to 2.5 mol%. The 4f-5d transition of the Ce 3+ allowed scintillation with a fast decay time. The absorption spectrum, X-ray induced emission spectrum, photo luminescence spectrum, laser luminescence spectrum and decay time of the scintillators were measured for studying the luminescence properties. From the X-ray induced emission spectrum result, we checked the trend between doping concentration and light yield. The laser induced luminescence spectrum was measured while changing the temperature from 300 K to 10 K. We also measured the decay time by using the laser excitation of the 0.15 mol% Ce 3+ doped glass scintillator. - Highlights: • Ce 3+ doped gadolinium-calcium-silicaborate glass scintillators were developed. • Glass is easily fabricated with large sizes and various doping materials. • The luminescence properties are studied by using various radiation sources. • The light yield and decay time were measured at low temperature. • One decay time component is found.

  7. Electron magnetic resonance of gadolinium-doped calcium fluoride

    Energy Technology Data Exchange (ETDEWEB)

    Biasi, R.S. de, E-mail: rsbiasi@ime.eb.br [Secao de Engenharia Mecanica e de Materiais, Instituto Militar de Engenharia, 22290-270 Rio de Janeiro, RJ (Brazil); Grillo, M.L.N., E-mail: mluciag@uerj.br [Instituto de Fisica, Universidade do Estado do Rio de Janeiro, 20550-013 Rio de Janeiro, RJ (Brazil)

    2012-06-15

    Electron magnetic resonance (EMR) spectra of gadolinium-doped calcium fluoride have been studied at room temperature for Gd concentrations between 0.01 and 2.00 mol%. Gd{sup 3+} ions in sites with two different symmetries were observed. One of the sites, with cubic symmetry, is unstable at room temperature and decays with a time constant of 2.2 day{sup -1}. The other site, with tetragonal symmetry, is stable and is attributed to Gd{sup 3+} ions in substitutional sites next to a charge-compensating F{sup -} interstitial ion. The linewidth and intensity of the EMR spectrum with tetragonal symmetry increase with increasing Gd concentration. A theoretical calculation based on the concentration dependence of the EMR linewidth yields an effective range of the exchange interaction between Gd{sup 3+} ions in CaF{sub 2} of 0.774 nm, of the same order as that of Gd{sup 3+} ions in other cubic ionic compounds.

  8. Gadolinium-, Calcium-, copper- and zirc complexes with riboflavin in acetone and acetonitrile

    International Nuclear Information System (INIS)

    Lugina, L.N.; Romanenko, V.I.; Davidenko, N.K.

    1983-01-01

    Using the methods of solubility and spectrophotometry, stability copstants Of complexes RFMSSUp(n+) (RF=riboflavin, Mnsup(n+)=Cdsup(3+), Ca 2+ , Cu 2+ and Zn 2+ ) in acetone and acetonitrile against the background of 1 mol/l LiClO 4 x3H 2 O have been determined. It was found that stability of copper and zinc complexes with riboflavin in acetone is higher than in acetonitrile, whereas the stability of gadolinium and calcium complexes, on the contrary, is higher in acetonitrile than in acetone. It is shown that the character of the absorption spectrum change of riboflavin in complexing with metal ions depends on the nature of coordinating cation

  9. Hybrid Calcium Phosphate-Polymeric Micelles Incorporating Gadolinium Chelates for Imaging-Guided Gadolinium Neutron Capture Tumor Therapy.

    Science.gov (United States)

    Mi, Peng; Dewi, Novriana; Yanagie, Hironobu; Kokuryo, Daisuke; Suzuki, Minoru; Sakurai, Yoshinori; Li, Yanmin; Aoki, Ichio; Ono, Koji; Takahashi, Hiroyuki; Cabral, Horacio; Nishiyama, Nobuhiro; Kataoka, Kazunori

    2015-06-23

    Gadolinium (Gd) chelates-loaded nanocarriers have high potential for achieving magnetic resonance imaging (MRI)-guided Gd neutron capture therapy (GdNCT) of tumors. Herein, we developed calcium phosphate micelles hybridized with PEG-polyanion block copolymers, and incorporated with the clinical MRI contrast agent Gd-diethylenetriaminepentaacetic acid (Gd-DTPA/CaP). The Gd-DTPA/CaP were nontoxic to cancer cells at the concentration of 100 μM based on Gd-DTPA, while over 50% of the cancer cells were killed by thermal neutron irradiation at this concentration. Moreover, the Gd-DTPA/CaP showed a dramatically increased accumulation of Gd-DTPA in tumors, leading to the selective contrast enhancement of tumor tissues for precise tumor location by MRI. The enhanced tumor-to-blood distribution ratio of Gd-DTPA/CaP resulted in the effective suppression of tumor growth without loss of body weight, indicating the potential of Gd-DTPA/CaP for safe cancer treatment.

  10. Optical properties of color centers in calcium-stabilized gadolinium gallium garnets

    International Nuclear Information System (INIS)

    Pogatshnik, G.J.; Cain, L.S.; Chen, Y.; Evans, B.D.

    1991-01-01

    The addition of small amounts of calcium during the crystal growth of large-diameter, gadolinium gallium garnet (GGG) crystals creates color centers that absorb in the near-uv region of the spectrum. Ultraviolet and γ-ray irradiation of the crystals produced changes in the intensities of the uv color-center bands along with a broad absorption throughout the visible spectrum. The color center that gives rise to an absorption band at 350 nm serves as a photoionizable donor center so that uv excitation results in a visible coloration of the crystals. The effects of oxidation and reduction treatments on the strength of the color-center bands and on the radiation response of the material were examined. Photoluminescence bands were observed in both reduced GGG crystals as well as crystals that were irradiated with neutrons. Visible coloration is likely to occur during flashlamp pumping of laser rods that utilize large-diameter GGG crystals as the laser host. The changes in the optical properties of the material under uv excitation indicate that the addition of small amounts of calcium to assist in the growth of large-diameter crystals is likely to result in the degradation of laser performance

  11. Structure and properties of gadolinium loaded calcium phosphate glasses

    International Nuclear Information System (INIS)

    Wang, Cuiling; Liang, Xiaofeng; Li, Haijian; Yu, Huijun; Li, Zhen; Yang, Shiyuan

    2014-01-01

    The glass samples with composition xGd 2 O 3 –(50 − x)CaO–50P 2 O 5 (0 ⩽ x ⩽ 9 mol%) were prepared by the conventional melt quench method. The structure and properties of gadolinium loaded in calcium phosphate glasses were investigated using XRD, SEM, DTA, IR and Raman spectroscopy. The XRD and SEM analysis for the samples show that the majority of samples are amorphous, and crystallization occurs when the content of Gd 2 O 3 containing is up to 6 mol%. Two main crystalline phases, Ca 2 P 2 O 7 and Gd 3 (P 2 O 7 ) 3 , are embedded in an amorphous matrix. IR and Raman data indicate that glass structure consists of predominantly metaphosphate (Q 2 ) units and the depolymerization of phosphate network with the addition of Gd 2 O 3 . Both the chemical durability and the glass transition temperature (T g ) are improved with the increase of Gd 2 O 3 , which suggests that the Gd acts a role of strengthening the cross-links between the phosphate chains of the glass

  12. Structure and properties of gadolinium loaded calcium phosphate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Cuiling [Analytical and Testing Center, Southwest University of Science and Technology, Mianyang 621010 (China); State Key Laboratory Cultivation Base for Nonmetal Composites and Functional Materials, Southwest University of Science and Technology, Mianyang 621010 (China); Liang, Xiaofeng, E-mail: XFLiang@swust.edu.cn [Analytical and Testing Center, Southwest University of Science and Technology, Mianyang 621010 (China); State Key Laboratory Cultivation Base for Nonmetal Composites and Functional Materials, Southwest University of Science and Technology, Mianyang 621010 (China); Li, Haijian; Yu, Huijun; Li, Zhen [Analytical and Testing Center, Southwest University of Science and Technology, Mianyang 621010 (China); State Key Laboratory Cultivation Base for Nonmetal Composites and Functional Materials, Southwest University of Science and Technology, Mianyang 621010 (China); Yang, Shiyuan [State Key Laboratory Cultivation Base for Nonmetal Composites and Functional Materials, Southwest University of Science and Technology, Mianyang 621010 (China)

    2014-10-15

    The glass samples with composition xGd{sub 2}O{sub 3}–(50 − x)CaO–50P{sub 2}O{sub 5} (0 ⩽ x ⩽ 9 mol%) were prepared by the conventional melt quench method. The structure and properties of gadolinium loaded in calcium phosphate glasses were investigated using XRD, SEM, DTA, IR and Raman spectroscopy. The XRD and SEM analysis for the samples show that the majority of samples are amorphous, and crystallization occurs when the content of Gd{sub 2}O{sub 3} containing is up to 6 mol%. Two main crystalline phases, Ca{sub 2}P{sub 2}O{sub 7} and Gd{sub 3}(P{sub 2}O{sub 7}){sub 3}, are embedded in an amorphous matrix. IR and Raman data indicate that glass structure consists of predominantly metaphosphate (Q{sup 2}) units and the depolymerization of phosphate network with the addition of Gd{sub 2}O{sub 3}. Both the chemical durability and the glass transition temperature (T{sub g}) are improved with the increase of Gd{sub 2}O{sub 3}, which suggests that the Gd acts a role of strengthening the cross-links between the phosphate chains of the glass.

  13. Contrast effects of a gadolinium filter

    International Nuclear Information System (INIS)

    Burgess, A.E.

    1981-01-01

    Several authors have suggested using heavy metal filters with K edges in the diagnostic energy range to reduce the width of the x-ray spectrum and hence reduce patient radiation exposure. This spectral narrowing also increases subject contrast and permits an increase in tube potential. Results of contrast measurements are presented for a 250 mu gadolinium filter. It was found that aluminum filter contrast could be matched by using 8 to 10 kVp higher potential with the gadolinium filter. Similar results were found for calcium tungstate and rare-earth screens. Measurements were also done to determine skin exposure and mAs ratios for both constant contrast and constant kVp technique conversion methods. A simple theory with one adjustable parameter gives a reasonable fit to the experimental results

  14. Enrichment of gadolinium-157 and gadolinium-155 by laser method

    International Nuclear Information System (INIS)

    Xinjun, Su; Xiaowei, Zhang; Zhiquan, Li

    2008-01-01

    Laser isotope separation experiments of gadolinium by atomic vapor method have been performed. Gadolinium-157 and gadolinium-155 were selectively photoionized by means of three linearly polarized dye lasers, the excitation process of which is based on the polarization selection rules. Gramme-magnitude of enriched gadolinium was obtained and the total abundance of gadolinium-157 and gadolinium-155 was in excess of 80%, and the product rating exceeded 200 mg/h. (author)

  15. Gadolinium neutron capture therapy

    International Nuclear Information System (INIS)

    Akine, Yasuyuki; Tokita, Nobuhiko; Tokuuye, Koichi; Satoh, Michinao; Churei, Hisahiko

    1993-01-01

    Gadolinium neutron capture therapy makes use of photons and electrons produced by nuclear reactions between gadolinium and lower-energy neutrons which occur within the tumor. The results of our studies have shown that its radiation effect is mostly of low LET and that the electrons are the significant component in the over-all dose. The dose from gadolinium neutron capture reactions does not seem to increase in proportion to the gadolinium concentration, and the Gd-157 concentration of about 100 μg/ml appears most optimal for therapy. Close contact between gadolinium and the cell is not necessarily required for cell inactivation, however, the effect of electrons released from intracellular gadolinium may be significant. Experimental studies on tumor-bearing mice and rabbits have shown that this is a very promising modality though further improvements in gadolinium delivery to tumors are needed. (author)

  16. Influence of gadolinium concentration on the EMR spectrum of Gd{sup 3+} in zircon

    Energy Technology Data Exchange (ETDEWEB)

    Biasi, R.S. de, E-mail: rsbiasi@ime.eb.b [Secao de Engenharia Mecanica e de Materiais, Instituto Militar de Engenharia, 22290-270 Rio de Janeiro, RJ (Brazil); Grillo, M.L.N., E-mail: mluciag@uerj.b [Instituto de Fisica, Universidade do Estado do Rio de Janeiro, 20550-013 Rio de Janeiro, RJ (Brazil)

    2009-11-01

    Electron magnetic resonance (EMR) spectra of gadolinium-doped zircon (ZrSiO{sub 4}) powders have been studied at room temperature for gadolinium concentrations between 0.20 and 1.0 mol%. The results suggest that Gd{sup 3+} ions occupy substitutional sites in the zircon lattice, that the electron magnetic resonance linewidth increases with increasing gadolinium concentration and that the range of the exchange interaction between Gd{sup 3+} ions is about 1.17 nm, larger than that of the same ion in other host lattices, such as ceria (CeO{sub 2}), strontium oxide (SrO) and calcium oxide (CaO). The fact that the electron magnetic resonance linewidth of the Gd{sup 3+} ion in polycrystalline zircon increases, regularly and predictably, with Gd concentration, shows that the Gd{sup 3+} ion can be used as a probe to study, rapidly and non-destructively, the crystallinity and degradation of ZrSiO{sub 4}.

  17. Subcellular SIMS imaging of gadolinium isotopes in human glioblastoma cells treated with a gadolinium containing MRI agent

    Science.gov (United States)

    Smith, Duane R.; Lorey, Daniel R.; Chandra, Subhash

    2004-06-01

    Neutron capture therapy is an experimental binary radiotherapeutic modality for the treatment of brain tumors such as glioblastoma multiforme. Recently, neutron capture therapy with gadolinium-157 has gained attention, and techniques for studying the subcellular distribution of gadolinium-157 are needed. In this preliminary study, we have been able to image the subcellular distribution of gadolinium-157, as well as the other six naturally abundant isotopes of gadolinium, with SIMS ion microscopy. T98G human glioblastoma cells were treated for 24 h with 25 mg/ml of the metal ion complex diethylenetriaminepentaacetic acid Gd(III) dihydrogen salt hydrate (Gd-DTPA). Gd-DTPA is a contrast enhancing agent used for MRI of brain tumors, blood-brain barrier impairment, diseases of the central nervous system, etc. A highly heterogeneous subcellular distribution was observed for gadolinium-157. The nuclei in each cell were distinctly lower in gadolinium-157 than in the cytoplasm. Even within the cytoplasm the gadolinium-157 was heterogeneously distributed. The other six naturally abundant isotopes of gadolinium were imaged from the same cells and exhibited a subcellular distribution consistent with that observed for gadolinium-157. These observations indicate that SIMS ion microscopy may be a viable approach for subcellular studies of gadolinium containing neutron capture therapy drugs and may even play a major role in the development and validation of new gadolinium contrast enhancing agents for diagnostic MRI applications.

  18. Preclinical studies on gadolinium neutron capture therapy

    International Nuclear Information System (INIS)

    Akine, Yasuyuki

    1994-01-01

    Gadolinium neutron capture therapy is based on radiations (photons and electrons) produced in the tumor by a nuclear reaction between gadolinium and lower-energy neutrons. Studies with Chinese hamster cells have shown that the radiation effect resulting from gadolinium neutron capture reactions is mostly of low LET and that released electrons are the significant component in the over-all dose. Biological dosimetry revealed that the dose does not seem to increase in proportion to the gadolinium concentration, leading to a conclusion that there is a range of gadolinium concentrations most efficient for gadolinium neutron capture therapy. The in vivo studies with transplantable tumors in mice and rabbits have revealed that close contact between gadolinium and the cell is not necessarily required for cell inactivation and that gadolinium delivery selective to tumors is crucial. The results show that the potential of gadolinium neutron capture therapy as a therapeutic modality appears very promising. (author)

  19. Gadolinium prevents high airway pressure-induced permeability increases in isolated rat lungs.

    Science.gov (United States)

    Parker, J C; Ivey, C L; Tucker, J A

    1998-04-01

    To determine the initial signaling event in the vascular permeability increase after high airway pressure injury, we compared groups of lungs ventilated at different peak inflation pressures (PIPs) with (gadolinium group) and without (control group) infusion of 20 microM gadolinium chloride, an inhibitor of endothelial stretch-activated cation channels. Microvascular permeability was assessed by using the capillary filtration coefficient (Kfc), a measure of capillary hydraulic conductivity. Kfc was measured after ventilation for 30-min periods with 7, 20, and 30 cmH2O PIP with 3 cmH2O positive end-expiratory pressure and with 35 cmH2O PIP with 8 cmH2O positive end-expiratory pressure. In control lungs, Kfc increased significantly to 1.8 and 3.7 times baseline after 30 and 35 cmH2O PIP, respectively. In the gadolinium group, Kfc was unchanged from baseline (0.060 +/- 0.010 ml . min-1 . cmH2O-1 . 100 g-1) after any PIP ventilation period. Pulmonary vascular resistance increased significantly from baseline in both groups before the last Kfc measurement but was not different between groups. These results suggest that microvascular permeability is actively modulated by a cellular response to mechanical injury and that stretch-activated cation channels may initiate this response through increases in intracellular calcium concentration.

  20. Gadolinium deposition within the dentate nucleus and globus pallidus after repeated administrations of gadolinium-based contrast agents - current status

    Energy Technology Data Exchange (ETDEWEB)

    Stojanov, Dragan [University of Nis, Faculty of Medicine, Nis (Serbia); Center for Radiology, Nis (Serbia); Aracki-Trenkic, Aleksandra [Center for Radiology, Nis (Serbia); Benedeto-Stojanov, Daniela [University of Nis, Faculty of Medicine, Nis (Serbia)

    2016-05-15

    Gadolinium-based contrast agents (GBCAs) have been used clinically since 1988 for contrast-enhanced magnetic resonance imaging (CE-MRI). Generally, GBCAs are considered to have an excellent safety profile. However, GBCA administration has been associated with increased occurrence of nephrogenic systemic fibrosis (NSF) in patients with severely compromised renal function, and several studies have shown evidence of gadolinium deposition in specific brain structures, the globus pallidus and dentate nucleus, in patients with normal renal function. Gadolinium deposition in the brain following repeated CE-MRI scans has been demonstrated in patients using T1-weighted unenhanced MRI and inductively coupled plasma mass spectroscopy. Additionally, rodent studies with controlled GBCA administration also resulted in neural gadolinium deposits. Repeated GBCA use is associated with gadolinium deposition in the brain. This is especially true with the use of less-stable, linear GBCAs. In spite of increasing evidence of gadolinium deposits in the brains of patients after multiple GBCA administrations, the clinical significance of these deposits continues to be unclear. Here, we discuss the current state of scientific evidence surrounding gadolinium deposition in the brain following GBCA use, and the potential clinical significance of gadolinium deposition. There is considerable need for further research, both to understand the mechanism by which gadolinium deposition in the brain occurs and how it affects the patients in which it occurs. (orig.)

  1. Investigation of gadolinium monophosphide at high temperatures

    International Nuclear Information System (INIS)

    Gordienko, S.P.; Gol'nik, V.F.; Mironov, K.E.

    1982-01-01

    Gadolinium monophosphide has been studied in vacuum at high temperatures using mass-spectrometric, chemical, X-ray phase and derivatographical analyses. It is established that gadolinium monophosphide at 2080-2465 K dissociates into atomic gadolinium, phosphorus and, P 2 molecules. According to Vant-Hoff and Gibbs-Helmholtz equations standard enthalpy of atomization ΔHsub(at) deg (298)=1027.3 kJ/mol and of formation ΔHsub(f) deg (298)=313.8 kJ/mol of gadolinium monophosphide are determined

  2. Use of gadolinium-based magnetic resonance imaging contrast agents and awareness of brain gadolinium deposition among pediatric providers in North America

    International Nuclear Information System (INIS)

    Mithal, Leena B.; Patel, Payal S.; Mithal, Divakar; Palac, Hannah L.; Rozenfeld, Michael N.

    2017-01-01

    Numerous recent articles have reported brain gadolinium deposition when using linear but not macrocyclic gadolinium-based contrast agents (GBCAs). To determine the current landscape of gadolinium use among pediatric institutions and the knowledge base of radiologists and referring providers with regard to GBCAs and brain gadolinium deposition. We e-mailed voluntary closed surveys to 5,390 physicians in various pediatric professional societies between January 2016 and March 2016. We used chi-square and Fisher exact tests to compare response distributions among specialties. We found that 80% of surveyed pediatric hospitals use macrocyclic contrast agents. In the last year, 58% switched their agent, most commonly to gadoterate meglumine, with the most common reason being brain gadolinium deposition. Furthermore, surveys indicated that 23% of hospitals are considering switching, and, of these, 83% would switch to gadoterate meglumine; the most common reasons were brain gadolinium deposition and safety. Radiologists were more aware of brain gadolinium deposition than non-radiologist physicians (87% vs. 26%; P<0.0001). Radiologists and referring providers expressed similar levels of concern (95% and 89%). Twelve percent of radiologists and 2% of referring providers reported patients asking about brain gadolinium deposition. Radiologists were significantly more comfortable addressing patient inquiries than referring pediatric physicians (48% vs. 6%; P<0.0001). The number of MRIs requested by referring pediatric physicians correlated with their knowledge of brain gadolinium deposition, contrast agent used by their hospital, and comfort discussing brain gadolinium deposition with patients (P<0.0001). Since the discovery of brain gadolinium deposition, many pediatric hospitals have switched to or plan to switch to a more stable macrocyclic MR contrast agent, most commonly gadoterate meglumine. Despite this, there is need for substantial further education of radiologists and

  3. Use of gadolinium-based magnetic resonance imaging contrast agents and awareness of brain gadolinium deposition among pediatric providers in North America

    Energy Technology Data Exchange (ETDEWEB)

    Mithal, Leena B. [Northwestern University, Feinberg School of Medicine, Ann and Robert H. Lurie Children' s Hospital of Chicago, Department of Pediatrics, Chicago, IL (United States); Patel, Payal S. [University of Arizona College of Medicine, Department of Pediatrics, Phoenix, AZ (United States); Mithal, Divakar [Northwestern University, Feinberg School of Medicine, Ann and Robert H. Lurie Children' s Hospital of Chicago, Department of Pediatric Neurology, Chicago, IL (United States); Palac, Hannah L. [Northwestern University, Biostatistics, Feinberg School of Medicine, Ann and Robert H. Lurie Children' s Hospital of Chicago, Chicago, IL (United States); Rozenfeld, Michael N. [University of Arizona College of Medicine, Department of Radiology, Phoenix, AZ (United States)

    2017-05-15

    Numerous recent articles have reported brain gadolinium deposition when using linear but not macrocyclic gadolinium-based contrast agents (GBCAs). To determine the current landscape of gadolinium use among pediatric institutions and the knowledge base of radiologists and referring providers with regard to GBCAs and brain gadolinium deposition. We e-mailed voluntary closed surveys to 5,390 physicians in various pediatric professional societies between January 2016 and March 2016. We used chi-square and Fisher exact tests to compare response distributions among specialties. We found that 80% of surveyed pediatric hospitals use macrocyclic contrast agents. In the last year, 58% switched their agent, most commonly to gadoterate meglumine, with the most common reason being brain gadolinium deposition. Furthermore, surveys indicated that 23% of hospitals are considering switching, and, of these, 83% would switch to gadoterate meglumine; the most common reasons were brain gadolinium deposition and safety. Radiologists were more aware of brain gadolinium deposition than non-radiologist physicians (87% vs. 26%; P<0.0001). Radiologists and referring providers expressed similar levels of concern (95% and 89%). Twelve percent of radiologists and 2% of referring providers reported patients asking about brain gadolinium deposition. Radiologists were significantly more comfortable addressing patient inquiries than referring pediatric physicians (48% vs. 6%; P<0.0001). The number of MRIs requested by referring pediatric physicians correlated with their knowledge of brain gadolinium deposition, contrast agent used by their hospital, and comfort discussing brain gadolinium deposition with patients (P<0.0001). Since the discovery of brain gadolinium deposition, many pediatric hospitals have switched to or plan to switch to a more stable macrocyclic MR contrast agent, most commonly gadoterate meglumine. Despite this, there is need for substantial further education of radiologists and

  4. Nephrogenic systemic fibrosis and gadolinium-based contrast media

    DEFF Research Database (Denmark)

    Thomsen, Henrik S; Morcos, Sameh K; Almén, Torsten

    2012-01-01

    PURPOSE: To update the guidelines of the Contrast Media Safety Committee (CMSC) of the European Society of Urogenital Radiology (ESUR) on nephrogenic systemic fibrosis and gadolinium-based contrast media. AREAS COVERED: Topics reviewed include the history, clinical features and prevalence of neph...... guidelines regarding gadolinium contrast agents minimises the risk of NSF • Potential long-term harm from gadolinium accumulation in the body is discussed.......PURPOSE: To update the guidelines of the Contrast Media Safety Committee (CMSC) of the European Society of Urogenital Radiology (ESUR) on nephrogenic systemic fibrosis and gadolinium-based contrast media. AREAS COVERED: Topics reviewed include the history, clinical features and prevalence...... of nephrogenic systemic fibrosis and the current understanding of its pathophysiology. The risk factors for NSF are discussed and prophylactic measures are recommended. The stability of the different gadolinium-based contrast media and the potential long-term effects of gadolinium in the body have also been...

  5. In vivo evaluation of neutron capture therapy effectivity using calcium phosphate-based nanoparticles as Gd-DTPA delivery agent.

    Science.gov (United States)

    Dewi, Novriana; Mi, Peng; Yanagie, Hironobu; Sakurai, Yuriko; Morishita, Yasuyuki; Yanagawa, Masashi; Nakagawa, Takayuki; Shinohara, Atsuko; Matsukawa, Takehisa; Yokoyama, Kazuhito; Cabral, Horacio; Suzuki, Minoru; Sakurai, Yoshinori; Tanaka, Hiroki; Ono, Koji; Nishiyama, Nobuhiro; Kataoka, Kazunori; Takahashi, Hiroyuki

    2016-04-01

    A more immediate impact for therapeutic approaches of current clinical research efforts is of major interest, which might be obtained by developing a noninvasive radiation dose-escalation strategy, and neutron capture therapy represents one such novel approach. Furthermore, some recent researches on neutron capture therapy have focused on using gadolinium as an alternative or complementary for currently used boron, taking into account several advantages that gadolinium offers. Therefore, in this study, we carried out feasibility evaluation for both single and multiple injections of gadolinium-based MRI contrast agent incorporated in calcium phosphate nanoparticles as neutron capture therapy agent. In vivo evaluation was performed on colon carcinoma Col-26 tumor-bearing mice irradiated at nuclear reactor facility of Kyoto University Research Reactor Institute with average neutron fluence of 1.8 × 10(12) n/cm(2). Antitumor effectivity was evaluated based on tumor growth suppression assessed until 27 days after neutron irradiation, followed by histopathological analysis on tumor slice. The experimental results showed that the tumor growth of irradiated mice injected beforehand with Gd-DTPA-incorporating calcium phosphate-based nanoparticles was suppressed up to four times higher compared to the non-treated group, supported by the results of histopathological analysis. The results of antitumor effectivity observed on tumor-bearing mice after neutron irradiation indicated possible effectivity of gadolinium-based neutron capture therapy treatment.

  6. Studies on gadolinium precipitation in moderator system of nuclear reactor

    International Nuclear Information System (INIS)

    Joshi, Akhilesh C.; Rajesh, Puspalata; Rufus, A.L.; Velmurugan, S.

    2015-01-01

    Gadolinium is used in the moderator system of many Pressurised Heavy Water Reactors (PHWRs) for start-up, shut-down and reactivity control during operation. It is very much essential to maintain gadolinium concentration in the system as desired. It has been reported that gadolinium gets precipitated in as oxalate in carbonated water under the influence of γ-radiation. Hence, studies were carried out to investigate the effect of dose, presence of other metal ions and metal surfaces on the precipitation of gadolinium. The results showed that the amount of carboxylic acids viz., formic acid and oxalic acid, formed due to radiolysis is dependent on the dose and that the curve passes though a maxima. Gadolinium is added in higher concentration in Advanced Heavy Water Reactor. So, experiments with high concentration of gadolinium were also carried out. Ultra pure water saturated with high purity CO 2 containing gadolinium and desired ion/surface was irradiated with γ-radiation from 60 Co source at 25°C to doses ranging from 2.5-16.6 Mrad. At lower doses, formation of carboxylic acids takes place but as the dose increases, decomposition of these acids starts and hence the concentration Vs dose passes through a maximum. It was found that precipitation of gadolinium as oxalate occurred at lower doses. At higher doses, it was seen that pH of the solution decreases and hence solubility of gadolinium oxalate increases. It was also observed that the amount of gadolinium precipitated varied linearly with the initial concentration of gadolinium varying from 2 ppm to 20 ppm. While for gadolinium concentration from 20 ppm to 400 ppm, gadolinium in particulate form was observed. The amount of carboxylic acids formed depends on the nature of cations present in solution. It was found that the amount of oxalic acid formed in the case of gadolinium was more than that formed in the case of sodium. Presence of metal oxides such as ZrO 2 formed over zircoloy surfaces was found to

  7. Thermal diffusivity of samarium-gadolinium zirconate solid solutions

    International Nuclear Information System (INIS)

    Pan, W.; Wan, C.L.; Xu, Q.; Wang, J.D.; Qu, Z.X.

    2007-01-01

    We synthesized samarium-gadolinium zirconate solid solutions and determined their thermal diffusivities, Young's moduli and thermal expansion coefficients, which are very important for their application in thermal barrier coatings. Samarium-gadolinium zirconate solid solutions have extremely low thermal diffusivity between 20 and 600 deg. C. The solid solutions have lower Young's moduli and higher thermal expansion coefficients than those of pure samarium and gadolinium zirconates. This combination of characteristics is promising for the application of samarium and gadolinium zirconates in gas turbines. The mechanism of phonon scattering by point defects is discussed

  8. Possible involvement of gadolinium chelates in the pathophysiology of nephrogenic systemic fibrosis: A critical review

    International Nuclear Information System (INIS)

    Idee, Jean-Marc; Port, Marc; Medina, Christelle; Lancelot, Eric; Fayoux, Emmanuelle; Ballet, Sebastien; Corot, Claire

    2008-01-01

    Nephrogenic systemic fibrosis (NSF) is a recently described, highly debilitating scleroderma-like disease occurring in patients with severe or end-stage renal failure. NSF is characterized by cutaneous papules and coalescing plaques ('peau d'orange' appearance) and a wooden consistency. It may ultimately cause disabling contractures of several joints, thus making many patients wheelchair-dependent. NSF has been associated to prior administration of gadolinium chelates (GC) used as contrast agents for magnetic resonance imaging. The best available treatment option at the present time is renal transplantation. The mechanism of NSF has not been fully elucidated. Several hypotheses have been proposed so far and are critically discussed in the present review article. Gadolinium has been found in skin biopsy samples of patients. The most widely accepted hypothesis is related to dechelation of less stable GC, progressively releasing free Gd 3+ which may subsequently lead to the attraction of CD34+, CD45+, pro-collagen+ circulating fibrocytes via the release of chemokines, thereby inducing systemic fibrosing disorders. Pre-existing renal failure may facilitate the process by delaying the excretion of GC. A complex interplay between gadolinium and co-factors (pro-inflammatory status, vascular injury, high dose of erythropoietin, high levels of calcium, phosphorus, etc.) may occur in patients with impaired renal function. This and other hypotheses remain to be investigated, as well as the role and independence of co-factors

  9. Gadolinium atom on neutron capture therapy

    International Nuclear Information System (INIS)

    Oda, Y.; Takagaki, M.; Miyatake, S.; Kikuchi, H.

    1994-01-01

    This report describes our measurements of gadolinium concentrations in several brain tumors obtained from fresh surgical specimens, as compared with corresponding concentrations in the blood. Moreover we tried to find out if the gadolinium concentration is high enough to use this compound in the treatment of brain tumors by neutron capture therapy. (J.P.N.)

  10. Stainless-Steel-Gadolinium Alloys; Alliages Acier Inoxydable-Gadolinium; Splavy iz nerzhaveyushchej stali i gadoliniya; Aleaciones de Acero Inoxidable-Gadolinio

    Energy Technology Data Exchange (ETDEWEB)

    Copeland, M.; Kato, H. [Albany Metallurgy Research Center, Bureau Of Mines, United States Department of the Interior, Albany, OR (United States)

    1964-06-15

    Because of the excellent corrosion resistance of stainless steels and the interest in gadolinium as a poison material, alloys of the two compounds were studied.Gadolinium was alloyed with AISE 304-type and chromium-type stainless steels; and then phase relationships, fabricability and properties were studied. The melting points of minor phases in alloys containing low percentages of gadolinium were noted to have a large effect on the structures resulting from equilibrating treatments and fabricability of the steels. When gadolinium was alloyed with the chromium-nickel-type steel, two minor phases, Fe{sub 9}Gd and Ni{sub 7}Gd, were observed to melt at 1080 Degree-Sign C, which limited the heat treatment and fabrication temperatures. Alloys with up to 5 wt.% gadolinium were successfully fabricated, and mechanical and corrosion properties were determined. No changes in the mechanical properties or resistance to hot-water corrosion of the steel were observed on alloying with up to about 3 wt.% gadolinium. Because of fabrication temperature limitations placed on chromium-nickel steels by the melting point of the minor phases, the effects of gadolinium on chromium steels were studied. Only one minor phase that melted at 1320 Degree-Sign C was noted on investigation of the 10 wt. % gadolinium isopleth in the chromium-iron-gadolinium alloy system. This property would enable one to equilibrate and fabricate these gadolinium steels at normally used temperatures. (author) [French] Les auteurs ont etudie des alliages d'acier inoxydable et de gadolinium en raison de l'excellente resistance a la corrosion des aciers inoxydables et de l 'interet que presente le gadolinium comme poison. Ils ont allie du gadolinium a des aciers inoxydables AISI de nuance 304 et des aciers au chrome et ils ont etudie le diagramme des phases, les possibilites de transformation et les proprietes de ces alliages. Dans les alliages d'une faible teneur en gadolinium, les points de fusion des phases

  11. Gadolinium depletion event in a CANDU® moderator - causes and recovery

    Energy Technology Data Exchange (ETDEWEB)

    Evans, D.W.; Price, J.; Swami, D.; Fracalanza, E.; Brett, M.E.; Puzzuoli, F.V.; Garg, A. [Ontario Power Generation, Pickering, Ontario (Canada); Herrmann, O.; Rudolph, A. [Kinectrics Inc., Toronto, Ontario (Canada); Stuart, C.; Glowa, G. [Atomic Energy of Canada Limited, Chalk River, Ontario (Canada); Smee, J. [Niagara Technical Consultants, St. Catharines, Ontario (Canada)

    2010-07-01

    Gadolinium nitrate is added to the moderator of CANDU units to maintain the reactor in a guaranteed shutdown state (GSS). In April 2008, after being in stable GSS for over 30 hours, one of Ontario Power Generation's Pickering-B units showed a gradual depletion of the dissolved gadolinium, despite purification being isolated. Further additions of gadolinium stabilized the moderator gadolinium concentration, however, since the root cause of the depletion was not immediately identified, the unit was placed in the drained shutdown state, per established procedures. The cumulative gadolinium depletion amounted to about 3200 grams, the equivalent of about 12 ppm. Analysis showed the presence of oxalate in the moderator water. It is well-known that gadolinium forms a very insoluble oxalate (log K{sub sp} = -29.1). Although sub-micron filtration of water samples did not show the presence of gadolinium particulate, the measured levels of oxalate, 1.2 to 2 ppm, were sufficient to react with 1.4 to 2.4 ppm of gadolinium. The source of oxalate was traced to radiolysis of dissolved CO{sub 2} species. This unit had been experiencing chronic low-level ingress of CO{sub 2} from the Annulus Gas System. Free oxalate ion is normally susceptible to radiolytic breakdown back to CO{sub 2}, but Gd{sup 3+} provides a stable sink for radiogenic oxalate, 2 Gd{sup 3+} + 3 C{sub 2}O{sub 4}{sup 2-} → Gd{sub 2}(C{sub 2}O{sub 4}){sub 3}. Subsequent testing confirmed that gadolinium oxalate is quite stable with respect to gamma irradiation. Inspections showed well-crystallized gadolinium oxalate deposited on moderator system surfaces. Estimates indicated that about 1200 grams of gadolinium could have deposited on in-core surfaces, including the outside of the calandria tubes. That amount of negative reactivity was a concern, since it would prevent re-start of the unit. OPG, with support from AECL-Chalk River and Kinectrics, embarked on a two-pronged chemistry recovery program aimed at 1

  12. Cost and availability of gadolinium for nuclear fuel reprocessing plants

    International Nuclear Information System (INIS)

    Klepper, O.H.

    1985-06-01

    Gadolinium is currently planned for use as a soluble neutron poison in nuclear fuel reprocessing plants to prevent criticality of solutions of spent fuel. Gadolinium is relatively rare and expensive. The present study was undertaken therefore to estimate whether this material is likely to be available in quantities sufficient for fuel reprocessing and at reasonable prices. It was found that gadolinium, one of 16 rare earth elements, appears in the marketplace as a by-product and that its present supply is a function of the production rate of other more prevalent rare earths. The potential demand for gadolinium in a fuel reprocessing facility serving a future fast reactor industry amounts to only a small fraction of the supply. At the present rate of consumption, domestic supplies of rare earths containing gadolinium are adequate to meet national needs (including fuel reprocessing) for over 100 years. With access to foreign sources, US demands can be met well beyond the 21st century. It is concluded therefore that the supply of gadolinium will quite likely be more than adequate for reprocessing spent fuel for the early generation of fast reactors. The current price of 99.99% pure gadolinium oxide lies in the range $50/lb to $65/lb (1984 dollars). By the year 2020, in time for reprocessing spent fuel from an early generation of large fast reactors, the corresponding values are expected to lie in the $60/lb to $75/lb (1984 dollars) price range. This increase is modest and its economic impact on nuclear fuel reprocessing would be minor. The economic potential for recovering gadolinium from the wastes of nuclear fuel reprocessing plants (which use gadolinium neutron poison) was also investigated. The cost of recycled gadolinium was estimated at over twelve times the cost of fresh gadolinium, and thus recycle using current recovery technology is not economical. 15 refs., 4 figs., 11 tabs

  13. Gadolinium recovery from aqueous pharmaceutical residuals by pulsed electrical discharge; Rueckgewinnung von Gadolinium aus pharmazeutischen Abwaessern mittels gepulster elektrischer Entladung

    Energy Technology Data Exchange (ETDEWEB)

    Lorenz, Tom; Froehlich, Peter [TU Bergakademie Freiberg (Germany); Seifert, Martin; Jacob-Seifert, Karin [FNE Entsorgungsdienste GmbH, Freiberg (Germany)

    2017-02-15

    Advanced oxidation process (AOP) is an oxidation step releasing reactive oxygen species by pulsed electrical discharge in aqueous systems. In contrast to processes generating ozone by external UV radiation this method is feasible for turbid liquids with solid particles. This method is currently used in particular in the field of purification of chemically polluted waste waters. In the present application AOP is applied for partial degradation of the organic ligand system of a gadolinium X-ray contrast agent to separate gadolinium subsequently by adding caustic soda to precipitate > 99% of gadolinium.

  14. Electrochemical characterization of calcium cobaltite based porous electrodes

    International Nuclear Information System (INIS)

    Fulgencio, E.B.G.A.; Vasconcelos, K.; Silva, R.M.; Melo, P.; Caetano, A.A.; Campos, L.F.A.; Dutra, R.P.S.; Macedo, D.A.

    2016-01-01

    Materials based on alkali metal oxides and alkaline earth metal have shown high technological interest in recent years. Among these materials, calcium and cobalt oxide composition Ca_3Co_4O_9 (C349) has emerged as thermoelectric material and, more recently, as cathode for solid oxide fuel cell (SOFC). In this study, C349 powder was obtained by solid state reaction of a mixture containing cobalt oxide and calcium carbonate from shellfish shells (CaCO_3 ∼ 98%), previously calcined at 550° C. Symmetrical cells (cathode / substrate / cathode) were prepared by screen printing of C349 electrodes in gadolinium-doped ceria substrates. The characterization by electrochemical impedance spectroscopy revealed that the C349 obtained in this work has an area specific resistance compatible with electrodes obtained by chemical routes (from literature). (author)

  15. Room temperature ferromagnetic gadolinium silicide nanoparticles

    Science.gov (United States)

    Hadimani, Magundappa Ravi L.; Gupta, Shalabh; Harstad, Shane; Pecharsky, Vitalij; Jiles, David C.

    2018-03-06

    A particle usable as T1 and T2 contrast agents is provided. The particle is a gadolinium silicide (Gd5Si4) particle that is ferromagnetic at temperatures up to 290 K and is less than 2 .mu.m in diameter. An MRI contrast agent that includes a plurality of gadolinium silicide (Gd.sub.5Si.sub.4) particles that are less than 1 .mu.m in diameter is also provided. A method for creating gadolinium silicide (Gd5Si4) particles is also provided. The method includes the steps of providing a Gd5Si4 bulk alloy; grinding the Gd5Si4 bulk alloy into a powder; and milling the Gd5Si4 bulk alloy powder for a time of approximately 20 minutes or less.

  16. Gadolinium photoionization process

    Science.gov (United States)

    Paisner, Jeffrey A.; Comaskey, Brian J.; Haynam, Christopher A.; Eggert, Jon H.

    1993-01-01

    A method is provided for selective photoionization of the odd-numbered atomic mass gadolinium isotopes 155 and 157. The selective photoionization is accomplished by circular or linear parallel polarized laser beam energy effecting a three-step photoionization pathway.

  17. Contrast opacification for CT from iodine, gadolinium and ytterbium

    International Nuclear Information System (INIS)

    Zwicker, C.; Langer, M.; Ullrich, V.; Felix, R.

    1993-01-01

    The absorption of the elements iodine, gadolinium und ytterbium in various dilutions was studied in relation to CT. Regression analysis and specific CT density measurements showed that absorption decreases from gadolinium to ytterbium and iodine. These results were confirmed by experiments using ten dogs. Boli of 0.5 molar gadolinium used for angio-CT without table movement showed the largest increase in density in the aorta and liver with an average of 190 HU and 21 HU respectively compared with iodine which gave 157 HU and 12 HU respectively. The animal experimental studies suggest that gadolinium and ytterbium are suitable contrast media for dynamic CT investigations. (orig.) [de

  18. Calculation qualification of gadolinium burnable poisons in water reactors

    International Nuclear Information System (INIS)

    Chaucheprat, P.

    1988-01-01

    The work presented in this thesis constitutes the qualification on the one end of Appolo-Neptune scheme for the gadolinium burnable poison in a pressurized water reactor, and on the other end of basis nuclear data on natural gadolinium. This study has permitted to reduce by a factor 3 the actual incertitude on the gadolinium poison comparatively at precisions cited in international benchmarks calculations [fr

  19. Gadolinium-enhanced magnetic resonance imaging in acute myocardial infarction

    International Nuclear Information System (INIS)

    Dijkman, P.R.M. van; Wall, E.E. van der; Roos, A. de; Doornbos, J.; Laarse, A. van der; Voorthuisen, A.E. van; Bruschke, A.V.G.; Rossum, A.C. van

    1990-01-01

    To evaluate he usefulness of the paramagnetic contrast agent Gadolinium-DTPA (diethylenetriaminepentaacetic acid) in Magnetic Resonance. Imaging of acute myocardial infarction, we studied a total of 45 patients with a first acute myocardial infarction by ECG-gated magnetic resonance imaging before and after intravenous administration of 0.1 mmol/kg Gadolinium-DTPA. All patients received thrombolytic treatment by intravenous streptokinase. The magnetic resonance imaging studies were preformed after a meam of 88 h (range 15-241) after the acute onset of acute myocardial infarction. Five patients without evidence of cardiac disease served as controls. Spin-echo measurements (TE 30 ms) were made using a Philips Gyroscan (0.5 Tesla) or a Teslacon II (0.6 Tesla). The 45 patients were divided into four groups of patients. In Group I( patients) Gadolinium-DTPA improved the detection of myocardial infarction by Gadolinium-DTPA. In Group II (20 patients) the magnetic resonance imaging procedure was repeated every 10 min for up to 40 min following administration of Gadolinium-DTPA. Optimal contrast enhancement was obtained 20-25 min after Gadolinium-DTPA. In Group III (27 patients) signal intensities were significantly higher in the patients who underwent the magnetic resonance imaging study more than 72 h (mean 120) after the acute event, suggesting increased acculumation of Gadolinium-DTPA in a more advanced stage of the infarction process. In Group IV (45 patients) Gadolinium-DTPA was administered in an attempt to distinguish between reperfused and nonreperfused myocardial areas after thrombolytic treatment for acute myocardial infarction. The signal intensities did not differ, but reperfused areas showed a more homogeneous aspect whereas nonreperfused areas were visualized as a more heterogeneous contrast enhancement. It is concluded that magnetic resonance imaging using the contrast agent Gadolinium-DTPA significantly improves the detection of infarcted myocardial areas

  20. Determination of gadolinium by the method of derivative spectrophotometry

    International Nuclear Information System (INIS)

    Aleksandrova, N.N.; Mishchenko, V.T.; Poluehktov, N.S.; Mukomel', V.L.

    1988-01-01

    Technique for gadolinium determination at the presence of interfering rare earth elements, which is based on the derivative spectrophotometry method, is suggested. The technique is of increased selectivity and allows to determine gadolinium in the mixtures with elements, which presence in solution makes impossible to determine gadolinium directly. At binary mixtures analysis Sr relative standard deviation does not exceed 0.03, while at the analysis of more complex mixtures Sr increases up to 0.06

  1. Gadolinium-based contrast agent toxicity: a review of known and proposed mechanisms.

    Science.gov (United States)

    Rogosnitzky, Moshe; Branch, Stacy

    2016-06-01

    Gadolinium chelates are widely used as contrast media for magnetic resonance imaging. The approved gadolinium-based contrast agents (GBCAs) have historically been considered safe and well tolerated when used at recommended dosing levels. However, for nearly a decade, an association between GBCA administration and the development of nephrogenic systemic fibrosis (NSF) has been recognized in patients with severe renal impairment. This has led to modifications in clinical practices aimed at reducing the potential and incidence of NSF development. Newer reports have emerged regarding the accumulation of gadolinium in various tissues of patients who do not have renal impairment, including bone, brain, and kidneys. Despite the observations of gadolinium accumulation in tissues regardless of renal function, very limited clinical data regarding the potential for and mechanisms of toxicity is available. This significant gap in knowledge warrants retrospective cohort study efforts, as well as prospective studies that involve gadolinium ion (Gd(3+)) testing in patients exposed to GBCA. This review examines the potential biochemical and molecular basis of gadolinium toxicity, possible clinical significance of gadolinium tissue retention and accumulation, and methods that can limit gadolinium body burden.

  2. Room temperature ferromagnetic gadolinium silicide nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Hadimani, Magundappa Ravi L.; Gupta, Shalabh; Harstad, Shane; Pecharsky, Vitalij; Jiles, David C.

    2018-03-06

    A particle usable as T1 and T2 contrast agents is provided. The particle is a gadolinium silicide (Gd5Si4) particle that is ferromagnetic at temperatures up to 290 K and is less than 2 .mu.m in diameter. An MRI contrast agent that includes a plurality of gadolinium silicide (Gd.sub.5Si.sub.4) particles that are less than 1 .mu.m in diameter is also provided. A method for creating gadolinium silicide (Gd5Si4) particles is also provided. The method includes the steps of providing a Gd5Si4 bulk alloy; grinding the Gd5Si4 bulk alloy into a powder; and milling the Gd5Si4 bulk alloy powder for a time of approximately 20 minutes or less.

  3. Validation of gadolinium burnout using PWR benchmark specification

    Energy Technology Data Exchange (ETDEWEB)

    Oettingen, Mikołaj, E-mail: moettin@agh.edu.pl; Cetnar, Jerzy, E-mail: cetnar@mail.ftj.agh.edu.pl

    2014-07-01

    Graphical abstract: - Highlights: • We present methodology for validation of gadolinium burnout in PWR. • We model 17 × 17 PWR fuel assembly using MCB code. • We demonstrate C/E ratios of measured and calculated concentrations of Gd isotopes. • The C/E for Gd154, Gd156, Gd157, Gd158 and Gd160 shows good agreement of ±10%. • The C/E for Gd152 and Gd155 shows poor agreement below ±10%. - Abstract: The paper presents comparative analysis of measured and calculated concentrations of gadolinium isotopes in spent nuclear fuel from the Japanese Ohi-2 PWR. The irradiation of the 17 × 17 fuel assembly containing pure uranium and gadolinia bearing fuel pins was numerically reconstructed using the Monte Carlo Continuous Energy Burnup Code – MCB. The reference concentrations of gadolinium isotopes were measured in early 1990s at Japan Atomic Energy Research Institute. It seems that the measured concentrations were never used for validation of gadolinium burnout. In our study we fill this gap and assess quality of both: applied numerical methodology and experimental data. Additionally we show time evolutions of infinite neutron multiplication factor K{sub inf}, FIMA burnup, U235 and Gd155–Gd158. Gadolinium-based materials are commonly used in thermal reactors as burnable absorbers due to large neutron absorption cross-section of Gd155 and Gd157.

  4. Gadolinium-enhanced turbo FLASH MR imaging of renal perfusion and excretion

    International Nuclear Information System (INIS)

    Watanabe, A.; Teresi, L.M.; Herbst, M.; O'Sullivan, R.M.; Lee, R.; Smith, C.; Renner, J.; Rappaport, A.; Bradley, W.G. Jr.

    1990-01-01

    This paper describes a novel approach to MR imaging of renal perfusion and excretion using gadolinium-enhanced, T1-weighted TURBP, fast low-angle shot (FLASH) imaging. Five normal volunteers and four patients were studied on a 1.5-T imaging system. Time-intensity curves of the appearance of gadolinium in each kidney and the bladder were then generated. In normal volunteers, marked first-pass enhancement of renal cortex followed by renal pyramids and collecting systems could be demonstrated on the first-pass gadolinium images. Delayed images showed hyperintense gadolinium within the bladder

  5. Behavior of gadolinium-based diagnostics in water treatment

    Energy Technology Data Exchange (ETDEWEB)

    Cyris, Maike

    2013-04-25

    Wastewater treatment plants throughout Europe are retrofitted for a sufficient removal of micropollutants. Most target compounds are eliminated efficiently at reasonable costs by oxidation. Sorption processes, on the other hand, are favored as no transformation products are formed. For oxidation, ozone is preferred presently. Its action is divided in two main reaction pathways: Via ozone and via hydroxyl radicals formed by ozone-matrix reactions. Oxidation efficiency strongly depends on reaction rate constants. Sorption processes are usually characterized, including sorption strength, by determination of isotherms. Also, for description of filtration processes isotherm data are necessary. So far, gadolinium chelates, used as contrast agents in magnetic resonance imaging, have not been investigated in both advanced wastewater treatment processes. The stable chelates are excreted without metabolization. Conventional wastewater treatment does not remove them substantially. They remain intact and no free Gd(III) is released. This may be changed due to oxidative treatment which potentially destroys the chelates, and Gd(III) ions which are toxic, contrary to the chelated form, may be liberated. Monitoring campaigns in wastewater and drinking water have been performed to demonstrate the relevance of gadolinium in such treatment steps. In a European monitoring campaign an average concentration of 118 ng L{sup -1} gadolinium has been determined for 75 wastewater treatment plants effluents, corresponding to a non-geogenic gadolinium concentration of 116 ng L{sup -1}. In drinking water in the Ruhr area, a densely populated region in Germany, gadolinium and the anomaly were measurable by a factor of five lower than the average in the investigated wastewater samples. The determined concentrations in drinking water are lower than acute toxic effect concentration. The speciation of gadolinium in the investigated samples is unknown, as only total element concentration has been

  6. Behavior of gadolinium-based diagnostics in water treatment

    International Nuclear Information System (INIS)

    Cyris, Maike

    2013-01-01

    Wastewater treatment plants throughout Europe are retrofitted for a sufficient removal of micropollutants. Most target compounds are eliminated efficiently at reasonable costs by oxidation. Sorption processes, on the other hand, are favored as no transformation products are formed. For oxidation, ozone is preferred presently. Its action is divided in two main reaction pathways: Via ozone and via hydroxyl radicals formed by ozone-matrix reactions. Oxidation efficiency strongly depends on reaction rate constants. Sorption processes are usually characterized, including sorption strength, by determination of isotherms. Also, for description of filtration processes isotherm data are necessary. So far, gadolinium chelates, used as contrast agents in magnetic resonance imaging, have not been investigated in both advanced wastewater treatment processes. The stable chelates are excreted without metabolization. Conventional wastewater treatment does not remove them substantially. They remain intact and no free Gd(III) is released. This may be changed due to oxidative treatment which potentially destroys the chelates, and Gd(III) ions which are toxic, contrary to the chelated form, may be liberated. Monitoring campaigns in wastewater and drinking water have been performed to demonstrate the relevance of gadolinium in such treatment steps. In a European monitoring campaign an average concentration of 118 ng L -1 gadolinium has been determined for 75 wastewater treatment plants effluents, corresponding to a non-geogenic gadolinium concentration of 116 ng L -1 . In drinking water in the Ruhr area, a densely populated region in Germany, gadolinium and the anomaly were measurable by a factor of five lower than the average in the investigated wastewater samples. The determined concentrations in drinking water are lower than acute toxic effect concentration. The speciation of gadolinium in the investigated samples is unknown, as only total element concentration has been determined

  7. Effect of organic bases on extraction of gadolinium carboxylates

    International Nuclear Information System (INIS)

    Sukhan, V.V.; Frankovskij, V.A.

    1982-01-01

    The effect of pyridine, 2-aminopyridine, benzylamine, antipyrine and o-phenanthroline on the extraction of capronates and bromocapronates of gadolinium with chloroform is studied. Out of the studied organic bases benzylamine produces the highest synergetic effect. In the absence of organic bases gadolinium carboxylates, solvated by three molecules of carbonic acids, are extracted into organic phase. A possihility of extractional separation of gadolinium from comparable amounts of iron with the mixture of 1 M solutions of caproic or bromocaproic acids with 1 M benzylamine from 0.1 M solution of tartaric acids is shown [ru

  8. Gadolinium-containing contrast media for radiographic examinations: a position paper

    International Nuclear Information System (INIS)

    Thomsen, Henrik S.; Almen, Torsten; Morcos, Sameh K.

    2002-01-01

    Recently, it has been suggested that gadolinium-based contrast media could be used for radiological examinations in patients with significant renal impairment, previous severe generalized reaction to iodinated contrast media or thyroid disease about to undergo radioactive iodine treatment; however, the indications for and risks of using gadolinium agents in this way are not well known; hence, the Contrast Media Safety Committee of The European Society of Urogenital Radiology reviewed the literature to issue a position paper on this subject. A comprehensive literature review was performed and the resulting report was discussed at the Ninth European Symposium on Urogenital Radiology in Genoa, Italy, June 2002. Review of the literature indicates that according to experimental data on animals gadolinium-based contrast media have more nephrotoxic potential than iodinated contrast media in equivalent X-ray attenuating doses; therefore, gadolinium-based contrast media should not replace iodinated contrast media in patients with renal insufficiency for radiographic examinations. For patients with previous severe generalized reactions to iodinated contrast media, and in patients about to undergo thyroid treatment with radioactive iodine gadolinium-based contrast media in approved intravenous doses, up to 0.3 mmol/kg body weight will not give diagnostic radiographic information in most cases. Gadolinium-based contrast media are not approved for radiographic examinations. (orig.)

  9. Magnetic resonance characteristics and susceptibility weighted imaging of the brain in gadolinium encephalopathy.

    Science.gov (United States)

    Samardzic, Dejan; Thamburaj, Krishnamoorthy

    2015-01-01

    To report the brain imaging features on magnetic resonance imaging (MRI) in inadvertent intrathecal gadolinium administration. A 67-year-old female with gadolinium encephalopathy from inadvertent high dose intrathecal gadolinium administration during an epidural steroid injection was studied with multisequence 3T MRI. T1-weighted imaging shows pseudo-T2 appearance with diffusion of gadolinium into the brain parenchyma, olivary bodies, and membranous labyrinth. Nulling of cerebrospinal fluid (CSF) signal is absent on fluid attenuation recovery (FLAIR). Susceptibility-weighted imaging (SWI) demonstrates features similar to subarachnoid hemorrhage. CT may demonstrate a pseudo-cerebral edema pattern given the high attenuation characteristics of gadolinium. Intrathecal gadolinium demonstrates characteristic imaging features on MRI of the brain and may mimic subarachnoid hemorrhage on susceptibility-weighted imaging. Identifying high dose gadolinium within the CSF spaces on MRI is essential to avoid diagnostic and therapeutic errors. Copyright © 2013 by the American Society of Neuroimaging.

  10. Production of gadolinium nitrate for TAPS 3 and 4 PHWR

    International Nuclear Information System (INIS)

    Mishra, S.L.; Ramakrishnan, P.; Iyer, N.S.; Singh, Harvinderpal

    2004-01-01

    In India, gadolinium nitrate is being used for the first time in PHWR at Tarapur. Gadolinium is preferred over boron due to high neutron cross section and the water soluble nitrate form works efficiently for reactivity control through moderator liquid poison addition system (MLPS) as well as for reactor shut down system (SDS2). Low concentration of gadolinium (0.1-0.2 g/l) in heavy water is sufficient to shut down the reactor in a very short time. After use, the small amount of gadolinium can be separated quickly from heavy water by ion exchange process. In this paper separation of Gd using of 2-ethyl hexyl phosphoric acid mono 2-ethyl hexyl ester EHEHPA as an extractant has been described

  11. Fundamental study of DSA images using gadolinium contrast agent

    International Nuclear Information System (INIS)

    Nagashima, Hiroyuki; Shiraishi, Akihisa; Igarashi, Hitoshi; Sakamoto, Hajime; Sano, Yoshitomo

    2002-01-01

    Most contrast agents used in digital subtraction angiography (DSA) are non-ionic iodinated contrast agents, which can cause severe side effects in patients with contraindications for iodine or allergic reactions to iodine. Therefore, DSA examinations using carbon dioxide gas or examinations done by magnetic resonance imaging (MRI) and ultrasound (US) were carried out in these patients. However, none of these examinations provided mages as clear as those of DSA with an iodinated contrast agent. We experienced DSA examination using a gadolinium contrast agent in a patient contraindicated for iodine. The patient had undergone MRI examination with a gadolinium contrast agent previously without side effects. The characteristics of gadolinium and the iodinated contrast agent were compared, and the DSA images obtained clinically using these media were also evaluated. The signal-to-noise (SN) ratio of the gadolinium contrast agent was the highest at tube voltages of 70 to 80 kilovolts and improved slightly when the image intensifier (I.I.) entrance dose was greater than 300 μR (77.4 nC/kg). The dilution ratios of five iodinated contrast agents showed the same S/N value as the undiluted gadolinium contrast agent. Clinically, the images obtained showed a slight decrease in contrast but provided the data necessary to make a diagnosis and made it possible to obtain interventional radiology (IVR) without any side effects. DSA examinations using a gadolinium contrast agent have some benefit with low risk and are thought to be useful for patients contraindicated for iodine. (author)

  12. Standard specification for sintered gadolinium oxide-uranium dioxide pellets

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2008-01-01

    1.1 This specification is for finished sintered gadolinium oxide-uranium dioxide pellets for use in light-water reactors. It applies to gadolinium oxide-uranium dioxide pellets containing uranium of any 235U concentration and any concentration of gadolinium oxide. 1.2 This specification recognizes the presence of reprocessed uranium in the fuel cycle and consequently defines isotopic limits for gadolinium oxide-uranium dioxide pellets made from commercial grade UO2. Such commercial grade UO2 is defined so that, regarding fuel design and manufacture, the product is essentially equivalent to that made from unirradiated uranium. UO2 falling outside these limits cannot necessarily be regarded as equivalent and may thus need special provisions at the fuel fabrication plant or in the fuel design. 1.3 This specification does not include (1) provisions for preventing criticality accidents or (2) requirements for health and safety. Observance of this specification does not relieve the user of the obligation to be aw...

  13. Synthesis and evaluation of gadolinium complexes based on PAMAM as MRI contrast agents.

    Science.gov (United States)

    Yan, Guo-Ping; Hu, Bin; Liu, Mai-Li; Li, Li-Yun

    2005-03-01

    Diethylenetriaminepentaacetic acid (DTPA) and pyridoxamine (PM) were incorporated into the amine groups on the surface of ammonia-core poly(amidoamine) dendrimers (PAMAM, Generation 2.0-5.0) to obtain dendritic ligands. These dendritic ligands were reacted with gadolinium chloride to yield the corresponding dendritic gadolinium (Gd) complexes. The dendritic ligands and their gadolinium complexes were characterized by(1)HNMR, IR, UV and elemental analysis. Relaxivity studies showed that the dendritic gadolinium complexes possessed higher relaxation effectiveness compared with the clinically used Gd-DTPA. After administration of the dendritic gadolinium complexes (0.09 mmol kg(-1) ) to rats, magnetic resonance imaging of the liver indicated that the dendritic gadolinium complexes containing pyridoxamine groups enhanced the contrast of the MR images of the liver, provided prolonged intravascular duration and produced highly contrasted visualization of blood vessels.

  14. Identification and characterization of gadolinium(III) complexes in biological tissue extracts.

    Science.gov (United States)

    Kahakachchi, Chethaka L; Moore, Dennis A

    2010-07-01

    The gadolinium species present in a rat kidney following intravenous administration of a gadolinium-based magnetic resonance contrast agent (Optimark™, Gadoversetamide injection) to a rat was examined in the present study. The major gadolinium species in the supernatant of the rat kidney tissue extracts was determined by reversed-phase liquid chromatography with online inductively coupled plasma optical emission spectrometry (HPLC-ICP-OES). The identity of the compound was established by liquid chromatography electrospray ionization mass spectrometry (LC-ESI-MS) detection. The principal gadolinium(III) complex in a rat kidney tissue extract was identified as Gd-DTPA-BMEA 24 Hrs and 7 days after a single intravenous injection of Optimark™ (gadoversetamide; Gd-DTPA-BMEA) at a dose of 5 mmol Gd/kg body weight. The study demonstrated for the first time the feasibility of the use of two complementary techniques, HPLC-ICP-OES and HPLC-ESI-MS to study the in vivo behavior of gadolinium-based magnetic resonance contrast media.

  15. Alkali metal and alkali earth metal gadolinium halide scintillators

    Science.gov (United States)

    Bourret-Courchesne, Edith; Derenzo, Stephen E.; Parms, Shameka; Porter-Chapman, Yetta D.; Wiggins, Latoria K.

    2016-08-02

    The present invention provides for a composition comprising an inorganic scintillator comprising a gadolinium halide, optionally cerium-doped, having the formula A.sub.nGdX.sub.m:Ce; wherein A is nothing, an alkali metal, such as Li or Na, or an alkali earth metal, such as Ba; X is F, Br, Cl, or I; n is an integer from 1 to 2; m is an integer from 4 to 7; and the molar percent of cerium is 0% to 100%. The gadolinium halides or alkali earth metal gadolinium halides are scintillators and produce a bright luminescence upon irradiation by a suitable radiation.

  16. Studies on polyaspartamide gadolinium complexes as potential magnetic resonance imaging contrast agents

    International Nuclear Information System (INIS)

    Yan Guoping; Liu Maili; Li Liyun

    2005-01-01

    Purpose: A series of polyaspartamide gadolinium complexes containing pyridoxamine groups were studied as the potential magnetic resonance imaging (MRI) contrast agents for liver enhancement. Methods: These polyaspartamide gadolinium complexes were prepared and evaluated by relaxivity, acute toxicity studies and magnetic resonance imaging of the liver in rats. Results: These polyaspartamide gadolinium complexes have higher relaxation effectiveness than that of the clinically used gadolinium diethylenetriaminepentaacetic acid and possess the low intravenous acute toxicities to Institute for Cancer Research (ICR) mice. Magnetic resonance imaging of the liver in rats indicated that they greatly enhance the contrast of magnetic resonance images and provide prolonged intravascular duration in the liver. Conclusion: These results indicated that the polyaspartamide gadolinium complexes containing pyridoxamine groups could be considered as the appropriate MRI contrast agents for liver enhancement

  17. Optimization of gadolinium burnable poison loading by the conjugate gradients method

    International Nuclear Information System (INIS)

    Drumm, C.R.

    1984-01-01

    Improved use of burnable poison is suggested for pressurized water reactors (PWR's) to insure a sufficiently negative moderator temperature coefficient of reactivity for extended burnup cycles and low leakage refueling patterns. The use of gadolinium as a burnable poison can lead to large axial fluctuations in the power distribution through the cycle. The goal of this work is to determine the optimal axial distribution of gadolinium burnable poison in a PWR to overcome the axial fluctuations, yielding an improved power distribution. The conjugate gradients optimization method is used in this work because of the high degree of nonlinearity of the problem. The neutron diffusion and depletion equations are solved for a one-dimensional one-group core model. The state variables are the flux, the critical soluble boron concentration, and the burnup. The control variables are the number of gadolinium pins per assembly and the beginning-of-cycle gadolinium concentration, which determine the gadolinium cross section. Two separate objectives are considered: 1) to minimize the power peaking factor, which will minimize the capital cost of the plant; and 2) to maximize the cycle length, which will minimize the fuel cost for the plant. It is shown in this work that optimizing the gadolinium distribution can yield an improved power distribution

  18. Magnon contribution to electrical resistance of gadolinium-dysprosium alloy single crystals

    International Nuclear Information System (INIS)

    Nikitin, S.A.; Slobodchikov, S.S.; Solomkin, I.K.

    1978-01-01

    The magnon, phonon and interelectron collision contributions to the electric resistance of single crystals of gadolinium-dysprosium alloys were quantified. A relationship was found to exist between the electric resistance and the variation of the topology of the Fermi surface on melting of gadolinium with dysprosium. It was found that gadolinium-dysprosium alloys, which have no helicoidal magnetic structure in magnetically ordered state, feature a spin-spin helicoidal-type correlations in the paramagnetic field

  19. Early Gadolinium Enhancement for Determination of Area at Risk

    DEFF Research Database (Denmark)

    Hammer-Hansen, Sophia; Leung, Steve W; Hsu, Li-Yueh

    2017-01-01

    OBJECTIVES: The aim of this study was to determine whether early gadolinium enhancement (EGE) by cardiac magnetic resonance (CMR) in a canine model of reperfused myocardial infarction depicts the area at risk (AAR) as determined by microsphere blood flow analysis. BACKGROUND: It remains controver......OBJECTIVES: The aim of this study was to determine whether early gadolinium enhancement (EGE) by cardiac magnetic resonance (CMR) in a canine model of reperfused myocardial infarction depicts the area at risk (AAR) as determined by microsphere blood flow analysis. BACKGROUND: It remains...... requires pathological validation. METHODS: Eleven dogs underwent 2 h of coronary artery occlusion and 48 h of reperfusion before imaging at 1.5-T. EGE imaging was performed 3 min after contrast administration with coverage of the entire left ventricle. Late gadolinium enhancement imaging was performed...... on native T1 and T2 maps. The size of EGE was significantly greater than the infarct by triphenyltetrazolium chloride (44.1 ± 15.8% vs. 20.7 ± 14.4%; p gadolinium enhancement (44.1 ± 15.8% vs. 23.5 ± 12.7%; p

  20. Characteristics of gadolinium-DTPA complex: a potential NMR contrast agent

    International Nuclear Information System (INIS)

    Weinmann, H.J.; Brasch, R.C.; Press, W.R.; Wesbey, G.E.

    1984-01-01

    Chelation of the rare-earth element gadolinium (Gd) with diethylenetriaminepentaacetic acid (DTPA) results in a strongly paramagnetic, stable complex that is well tolerated in animals. The strongly paramagnetic gadolinium complex reduces hydrogen-proton relaxation times even in low concentrations (less than 0.01 mmol/L). The pharmacokinetic behavior of intravenously delivered Gd-DTPA is similar to the well known iodinated contrast agents used in urography and angiography; excretion is predominately through the kidneys with greater than 90% recovery in 24 hr. The intravenous LD 50 of the meglumine salt of Gd-DTPA is 10 mmol/kg for the rat; in vivo there is no evidence of dissociation of the gadolinium ion from the DTPA ligand. The combination of strong proton relaxation, in-vivo stability, rapid urinary excretion, and high tolerance favors the further development and the potential clinical application of gadolinium-DTPA as a contrast enhancer in magnetic resonance imaging

  1. Formation of nanoclusters of gadolinium atoms in silicon

    International Nuclear Information System (INIS)

    Iliev, Kh.M.; Saparniyazova, Z.M.; Ismajlov, K.A.; Madzhitov, M.Kh.

    2011-01-01

    A technology of stage wise low temperature diffusion of gadolinium into silicon that makes it possible to form nanoclusters of impurity atoms with a significant magnetic moment distributed throughout the volume of the material has been developed. It is shown that, unlike the samples obtained by high temperature diffusion doping, the samples prepared by the new technology do not have surface erosion, and alloys and silicides are not formed in the near surface region. Nanoclusters of impurity atoms of gadolinium in the volume of the crystal lattice of the silicon are studied using an MIK-5 infrared microscope. It is found that, in the stage wise low temperature diffusion, the temperature and time of the diffusion have an effect not only on the depth of penetration of the impurities but also on the sizes of the resulting clusters; these factors can also prevent the formation of clusters. The study of the effect of low temperature treatments on the size and distribution of clusters shows that, upon annealing in the temperature range of 500-700 degrees Celsius, the ordering of the clusters of gadolinium impurity atoms is observed. A further increase in the annealing temperature leads to the destruction of gadolinium clusters in the silicon bulk. (authors)

  2. The obtaining a high-grade gadolinium concentrate

    International Nuclear Information System (INIS)

    Soltysiak, I.; Ozga, W.

    1982-01-01

    Gadolinium concentrates obtained by the fractional precipitation of lanthanon-potassium double chromates were separated by ion exchange with 0,4 M lactic acid solution in the presence of 0,1 M ammonium nitrate at pH of the medium 2,95-3,4. It was found out, that using the fractional precipitation of lanthanon-potassium double chromates (as the fast and cheap method that does not need special equipment) together with ion exchange separation with lactic acid solution as the eluent gave a highgrade gadolinium concentrate in a quick and economical way. (author)

  3. Use of gadolinium as neutron poison in 540 MWe PHWR

    International Nuclear Information System (INIS)

    Nag, P.K.; Fernando, M.P.S.; Kumar, A.N.

    2006-01-01

    In Pressurised heavy water reactors (PHWRs), neutron poison in the moderator is used to compensate the excess reactivity present in the core on different occasions such as xenon decay during synchronization just after poison out period or start ups from xenon free conditions. It is also used in secondary shutdown system (SDS-2), where required amount of neutron poison is injected directly into the moderator within 2.5 seconds. Further, it is also used for over poisoning the moderator to achieve the guaranteed shutdown state when the regular shutdown systems are taken for maintenance. Generally, two types of moderator poisons are used in power reactors to balance the reactivity of the core and they are boron and gadolinium. Gadolinium is used in the form of gadolinium nitrate (Gd(NO 3 ) 3 .6H 2 O). The paper gives the details of estimation of reactivity coefficients of gadolinium for 540 MWe PHWR for different operating conditions. These neutron poisons are converted into non-absorbing elements and therefore their effective worth will decrease as reactor operation proceeds. The rate of burning of neutron absorbing isotopes depends on its magnitude of absorption cross-section and thermal flux seen by them. The present study discusses the burning characteristics of gadolinium during power operation in 540 MWe PHWR. It is established by detailed analysis that the rate of positive reactivity realized due to burning of neutron absorbing Gd isotopes almost match with the build up rate of xenon. The burning half lives of boron and gadolinium is worked out for different power levels. (author)

  4. Study of burnable poisons and gadolinium qualification in light water reactors

    International Nuclear Information System (INIS)

    Nasr, Mohamed.

    1981-09-01

    The aim of this work is to develop a calculation procedure for analyzing light water moderated reactors utilizing gadolinium as a burnable poison. The main points of this work can be summarized as follows: the available cross section data of gadolinium were analysed and corrected whenever it was necessary. The processes which include required precautions for obtaining multigroup cross sections were defined; an exhaustive study of the assumptions used in multicell calculation methods allowed the definition of option to be used for obtaining good results without excessive calculation cost. This study was followed by the interpretation of experimental results; when gadolinium is used in grain structure, a problem of double heterogeneity is encountered. A new calculation method was developed for such situations. Its validity was confirmed by a comparison with the Monte Carlo method; the problems encountered in performing a study of burn up of fuel elements containing gadolinium were analysed and the necessary precautions were established. The effect of the initial charge and geometrical form of the gadolinium and the behavior of lattices during the burn up were examined [fr

  5. Extraction of gadolinium from high flux isotope reactor control plates

    International Nuclear Information System (INIS)

    Kohring, M.W.

    1987-04-01

    Gadolinium-153 is an important radioisotope used in the diagnosis of various bone disorders. Recent medical and technical developments in the detection and cure of osteoporosis, a bone disease affecting an estimated 50 million people, have greatly increased the demand for this isotope. The Oak Ridge National Laboratory (ORNL) has produced 153 Gd since 1980 primarily through the irradiation of a natural europium-oxide powder followed by the chemical separation of the gadolinium fraction from the europium material. Due to the higher demand for 153 Gd, an alternative production method to supplement this process has been investigated. This process involves the extraction of gadolinium from the europium-bearing region of highly radioactive, spent control plates used at the High Flux Isotope Reactor (HFIR) with a subsequent re-irradiation of the extracted material for the production of the 153 Gd. Based on the results of experimental and calculational analyses, up to 25 grams of valuable gadolinium (≥60% enriched in 152 Gd) resides in the europium-bearing region of the HFIR control components of which 70% is recoverable. At a specific activity yield of 40 curies of 153 Gd for each gram of gadolinium re-irradiated, 700 one-curie sources can be produced from each control plate assayed

  6. Chemical aspects of gadolinium nitrate as soluble nuclear poison in Savannah River Plant reactors

    International Nuclear Information System (INIS)

    Baumann, E.W.

    1978-01-01

    The aqueous solution chemistry of gadolinium nitrate was studied to identify conditions that interfere with successful cleanup of gadolinium in Savannah River Plant reactor systems. Injecting a gadolinium nitrate solution into the D 2 O coolant-moderator constitutes a supplementary mode of reactor shutdown. The resulting approximately 0.001M gadolinium nitrate solution is then deionized by recirculation through mixed-bed ion exchange resins before reactor operation is resumed

  7. MR imaging of gestational trophoblastic tumor: role of gadolinium enhancement

    International Nuclear Information System (INIS)

    Choi, Si Young; Byun, Jae Young; Kim, Bum Su; Yun, Young Hyun; Mun, Kyung Mi; Park, Kyung Sin; Kim, Byung Kee; Bae, Seog Nyeon; Shinn, Kyung Sub.

    1997-01-01

    The purpose of this study is to investigate the role of gadolinium enhanced MR imaging in the evaluation of gestational trophoblastic tumors (invasive mole and choriocarcinoma). Pre-enhanced T1-and T2-weighted images and gadolinium enhanced T1-weighted images of 34 gestational trophoblastic tumors (15 choriocarcinomas, 19 invasive moles) were retrospectively evaluated and enhancement patterns were analyzed. Morphologica differences and structural characteristics were analyzed by the evaluation of tumor margin, patterns of hemorrhagic necroses, the development of intratumoral vascularity, and molar villi. Graded scores of MR findings between pre- and gadolinium enhanced images were based on the following criteria : 1) visualization of tumor margin 2) distinction between tumor necrosis and zone of trophoblastic proliferation ; and 3) molar villi. Statistical differences between graded scores of pre- and post-enhanced images were analyzed. Gadolinium enhanced MR imaging was helpful for the visualization of tumor characteristics in gestational trophoblastic tumors and in differential diagnosis between invasive mole and choriocarcinoma. (author). 16 refs., 4 tabs., 4 figs

  8. Use of gadolinium-DTPA in inflammatory skeletal diseases

    International Nuclear Information System (INIS)

    Mueller-Miny, H.; Reiser, M.; Erlemann, R.; Peters, P.E.

    1989-01-01

    In bacterial osteomyelitis and arthritis paraossal spreading is sensitively detected by gadolinium-DTPA. Abscessous cavities and membranes are better imaged than with T1- and T2-weighted MRT sequences without contrast medium. In chronic osteomylitis it is of advantage, that also florid inflammatory processes can be detected. Gadolinium-DTPA selectively induces a signal increase in the synovitic pannus, that allows the differentiation from articular effusion. In inflammed particular soft tissue only a retarded signal increase is detectable. (author)

  9. Actual clinical use of gadolinium-chelates for non-MRI applications

    Energy Technology Data Exchange (ETDEWEB)

    Strunk, Holger M; Schild, H [Department of Radiology, University of Bonn, Sigmund-Freud-Strasse 25, 53105, Bonn (Germany)

    2004-06-01

    For many years, alternatives to iodinated X-ray contrast media have been sought. Of the contrast media investigated to date, only CO{sub 2} and the gadolinium-chelates have been shown to be viable alternatives for selected X-ray examinations. Therefore, we have reviewed the general literature and that specific for gadopentetate (Magnevist) in particular, since this agent has been studied the most. This review indicates that diagnostic CT examinations can be achieved following the intravenous administration of gadolinium-containing contrast media (CM) for evaluation of aortic abnormalities. Gadolinium-containing CM at the dose approved for MR imaging are not useful for CT evaluation of the abdominal parenchymal organs. Intravenous/intraarterial injections have also been used in a variety of angiographic and interventional procedures. Image quality, however, is generally inferior to iodinated contrast media. Gadolinium-containing CM require no special handling and can be administered by hand injection or via conventional angiographic automated injectors with the same flow rates and pressures as are used with iodinated contrast media. For CT, a peripheral bolus injection of a diluted gadolinium agent (1:1 with saline) of 60-90 ml at 3-5 ml/s is usually performed. Similar to all other gadolinium-chelates, the non-MRI use of gadopentetate (Magnevist) is not approved by regulatory agencies. However, the literature suggests that a dose of 0.3-0.4 mmol/kg b.w. has been safely administered for CT as well as for angiography and interventional procedures intravenously and intraarterially. Even at this dose, though, this results in a relatively small overall volume to be injected, which limits utility somewhat. (orig.)

  10. Actual clinical use of gadolinium-chelates for non-MRI applications

    International Nuclear Information System (INIS)

    Strunk, Holger M.; Schild, H.

    2004-01-01

    For many years, alternatives to iodinated X-ray contrast media have been sought. Of the contrast media investigated to date, only CO 2 and the gadolinium-chelates have been shown to be viable alternatives for selected X-ray examinations. Therefore, we have reviewed the general literature and that specific for gadopentetate (Magnevist) in particular, since this agent has been studied the most. This review indicates that diagnostic CT examinations can be achieved following the intravenous administration of gadolinium-containing contrast media (CM) for evaluation of aortic abnormalities. Gadolinium-containing CM at the dose approved for MR imaging are not useful for CT evaluation of the abdominal parenchymal organs. Intravenous/intraarterial injections have also been used in a variety of angiographic and interventional procedures. Image quality, however, is generally inferior to iodinated contrast media. Gadolinium-containing CM require no special handling and can be administered by hand injection or via conventional angiographic automated injectors with the same flow rates and pressures as are used with iodinated contrast media. For CT, a peripheral bolus injection of a diluted gadolinium agent (1:1 with saline) of 60-90 ml at 3-5 ml/s is usually performed. Similar to all other gadolinium-chelates, the non-MRI use of gadopentetate (Magnevist) is not approved by regulatory agencies. However, the literature suggests that a dose of 0.3-0.4 mmol/kg b.w. has been safely administered for CT as well as for angiography and interventional procedures intravenously and intraarterially. Even at this dose, though, this results in a relatively small overall volume to be injected, which limits utility somewhat. (orig.)

  11. Microwave and optical diagnostics in a gadolinium plasma; Diagnostics hyperfrequence et optique dans un plasma magnetise de gadolinium

    Energy Technology Data Exchange (ETDEWEB)

    Larousse, B. [CEA Centre d`Etudes de Saclay, 91 - Gif-sur-Yvette (France). Dept. des Procedes d`Enrichissement]|[Conservatoire National des Arts et Metiers (CNAM), 75 - Paris (France)

    1997-12-31

    The optimization of the separation process of the gadolinium isotopes by Ion Cyclotron Resonance requires a precise knowledge of the physical characteristics of the plasma. Thus, two kinds of diagnostics have been developed: the first one to estimate the microwave power inside the source and the second one to measure the density of atomic and ionic of the gadolinium inside the plasma source and in front of the collector. Microwave diagnostic: A microstrip antenna has been designed and developed in order to characterize the microwave at 36 GHz frequency in the plasma source. The experimental results for different plasma regimes are presented. The measurements inside the plasma source show a maximum of microwave absorption for an argon pressure of 10{sup -4} mb (93% of absorption of the incident wave in the conditions of isotope separation). Laser absorption diagnostic: The theory of laser absorption in presence of a magnetic field is recalled and the first results are presented. In the spectral range between 560 and 620 nm, corresponding to high energy levels of gadolinium, no signal is obtained so that the density is below the detection limit 10{sup 10} cm{sup -3}. In the spectral range between 380 and 400 nm, two lines are observed, issue from the fundamental and metastable (633 cm{sup -1}) levels. The density of metastable level of gadolinium ions is about 10{sup 10} cm{sup -3} with a relative precision of 15 % and its variation is studied as a function of argon pressure, at different sections of the plasma column (source, collector). The achieved set of measurements has been performed in order to check the theoretical models. (author) 32 refs.

  12. Magnetic resonance ventriculography with gadolinium DTPA: report of two cases

    International Nuclear Information System (INIS)

    Siebner, H.R.; Einsiedel, H. von; Conrad, B.

    1997-01-01

    We report intrathecal use of gadolinium DTPA for MRI of the cerebrospinal fluid (CSF). In two patients with leptomeningeal carcinomatosis, we injected 0.01 mmol gadolinium DTPA into the lateral ventricle via an Ommaya device. Coronal T1-weighted images of the head were obtained at 0.2 T prior to and after injection. There was pronounced enhancement of CSF close to the injection site, allowing good delineation of CSF and surrounding brain tissue. No side effects occurred. MRI with intrathecal administration of highly diluted gadolinium DTPA may be a promising alternative to conventional investigation of CSF-filled cavities using iodinated X-ray contrast media or radionuclides. (orig.). With 3 figs

  13. Impact of New Gadolinium Cross Sections on Reaction Rate Distributions in 10 * 10 BWR Assemblies

    Energy Technology Data Exchange (ETDEWEB)

    Perret, G.; Murphy, M.F.; Jatuff, F.; Chawla, R. [Paul Scherrer Inst, CH-5232 Villigen, (Switzerland); Sublet, J.Ch.; Bouland, O. [DEN, Commissariat Energie Atom, F-13108 St Paul Les Durance, (France); Chawla, R. [Ecole Polytech Fed Lausanne, CH-1015 Lausanne, (Switzerland)

    2009-07-01

    Radial distributions of the total fission rate and the {sup 238}U-capture-to-total-fission (C{sub 8}/F{sub tot}) ratio were measured in SVEA-96+ and SVEA-96 Optima2 assemblies during the LWR-PROTEUS program. Fission rates predicted using MCNPX with JEFF-3.1 cross sections underestimated the measured values in the gadolinium-poisoned pins of the SVEA-96 Optima2 assembly; similarly, C{sub 8}/F{sub tot} ratios were overestimated in some gadolinium-poisoned pins of the SVEA-96+ assembly. A considerable effort was invested at the Paul Scherrer Institut to explain the discrepancies in gadolinium pins, without success. Recently, gadolinium cross sections were measured at the Rensselaer Polytechnic Institute by Leinweber et al. and differed significantly from current library values. ENDF/B-VII.0 gadolinium cross sections have currently been modified to include the new measurements, and these data have been processed with NJOY to yield files usable by MCNPX. Fission rates in the gadolinium-poisoned fuel pins of the SVEA-96 Optima2 pins were increased by 1.4 to 2.0% using the newly produced cross sections, yielding to a better agreement with the experimental values. Predicted C{sub 8}/F{sub tot} ratios were decreased on average by 1.7% in both clustered and un-clustered groups of gadolinium-poisoned fuel pins of the SVEA-96+ assembly correcting the over predictions previously reported in the clustered gadolinium pins. Earlier reported discrepancies observed in PROTEUS integral experiments, between measured and calculated reaction rates in the gadolinium-poisoned pins, might thus be due to inaccurate gadolinium cross sections. The PROTEUS results support the new thermal and epithermal gadolinium data measured by Leinweber et al. (authors)

  14. Gadolinium-Based GaN for Neutron Detection with Gamma Discrimination

    Science.gov (United States)

    2016-06-01

    Gadolinium-Based GaN for Neutron Detection with Gamma Discrimination Distribution Statement A. Approved for public release; distribution is...Final Technical Report BRBAA08-Per5-Y-1-2-0030 Title: “Gadolinium-Based GaN for Neutron Detection with Gamma Discrimination ” Grant...Analysis  .............................................................................................  23   6.   Gamma-ray Discrimination

  15. performance calculations of gadolinium oxide and boron nitride coated fuel

    International Nuclear Information System (INIS)

    Tanker, E.; Uslu, I.; Disbudak, H.; Guenduez, G.

    1997-01-01

    A comparative study was performed on the behaviour of natural uranium dioxide-gadolinium oxide mixture fuel and boron nitride coated low enriched fuel in a pressurized water reactor. A fuel element containing one burnable poison fuel pins was modeled with the computer code WIMS, and burn-up dependent critically, fissile isotope inventory and two dimensional power distribution were obtained. Calculations were performed for burnable poison fuels containing 5% and 10% gadolinium oxide and for those coated with 1μ,5μ and 10μ of boron nitride. Boron nitride coating was found superior to gadolinium oxide on account of its smoother criticality curve, lower power peaks and insignificant change in fissile isotope content

  16. Selective photoionization of gadolinium isotopes with a polarized laser

    International Nuclear Information System (INIS)

    Le Guyadec, E.

    1990-06-01

    The aim of this study is the use of gadolinium 157 as burnable poison in nuclear reactors. Spectroscopic isotopic displacements between Gd 156 and Gd 157 are low and the separation method studied is based on differentiated behavior, concerning polarized light, of even and odd gadolinium isotopes coming from their difference of nuclear spin. On this principle is based the simplest photoionization scheme. Selective ionization of odd isotopes is realized from the fundamental state with three resonating photons colinearly polarized. The experimental study confirms the possibility of efficient photoionization. The measured selectivity between Gd 157 and even isotope is over 48 in defined conditions because it can be destroyed by a magnetic field or if photons are not well polarized. Calculations and observations are in good agreement. Odd gadolinium isotope separation is feasible and effects preventing separation are evidenced [fr

  17. Advantages of gadolinium based ultrasmall nanoparticles vs molecular gadolinium chelates for radiotherapy guided by MRI for glioma treatment

    OpenAIRE

    Le Duc, G.; Roux, S.; Paruta-Tuarez, A.; Dufort, S.; Bräuer, E.; Marais, A.; Truillet, C.; Sancey, L.; Perriat, P.; Lux, F.; Tillement, O.

    2014-01-01

    AGuIX nanoparticles are formed of a polysiloxane network surrounded by gadolinium chelates. They present several characteristics. They are easy to produce, they present very small hydrodynamic diameters (

  18. Influence of calcium and lithium on the densification and electrical conductivity of gadolinia-doped ceria

    International Nuclear Information System (INIS)

    Porfirio, Tatiane Cristina

    2011-01-01

    In this work, the use of calcium and lithium as sintering aid to gadolinia-doped ceria was systematically investigated. The main purpose was to verify the influence of these additives on the densification and electrical conductivity of sintered ceramics. Powder compositions containing up to 1.5 mol% (metal basis) of calcium or lithium were prepared by both solid state reaction and oxalate coprecipitation methods. The main characterization techniques were thermal analyses, X-ray diffraction, scanning electron microscopy and electrical conductivity by impedance spectroscopy. Both additives promoted densification of gadolinia-doped ceria. The densification increases with increasing the additive content. Different effects on microstructure and electrical conductivity result from the method of preparation, e.g., solid state reaction or coprecipitation. Calcium addition greatly enhances the grain growth compared to lithium addition. The electrical conductivity of specimens containing a second additive is lower than that of pure gadolinia-doped ceria. Both additives influence the intergranular conductivity and favor the exudation of gadolinium out of the solid solution. (author)

  19. A model to calculate the burn of gadolinium in PWR

    International Nuclear Information System (INIS)

    Sannazzaro, L.R.

    1983-01-01

    A cell model to calculate the burnup of a PWR fuel element with gadolinium as a poison, projected by KWU, is presented. With the model proposed, the burn of the gadolinium isotopes is analyzed, as well as the effect of these isotopes in the fuel element behaviour. The results obtained with this cell model are compared with those obtained by a conventional cell model. (E.G.) [pt

  20. Standard test methods for analysis of sintered gadolinium oxide-uranium dioxide pellets

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2006-01-01

    1.1 These test methods cover procedures for the analysis of sintered gadolinium oxide-uranium dioxide pellets to determine compliance with specifications. 1.2 The analytical procedures appear in the following order: Section Carbon (Total) by Direct CombustionThermal Conductivity Method C1408 Test Method for Carbon (Total) in Uranium Oxide Powders and Pellets By Direct Combustion-Infrared Detection Method Chlorine and Fluorine by Pyrohydrolysis Ion-Selective Electrode Method C1502 Test Method for Determination of Total Chlorine and Fluorine in Uranium Dioxide and Gadolinium Oxide Gadolinia Content by Energy-Dispersive X-Ray Spectrometry C1456 Test Method for Determination of Uranium or Gadolinium, or Both, in Gadolinium Oxide-Uranium Oxide Pellets or by X-Ray Fluorescence (XRF) Hydrogen by Inert Gas Fusion C1457 Test Method for Determination of Total Hydrogen Content of Uranium Oxide Powders and Pellets by Carrier Gas Extraction Isotopic Uranium Composition by Multiple-Filament Surface-Ioni...

  1. Demonstration of pulmonary embolism with gadolinium-enhanced spiral CT

    Energy Technology Data Exchange (ETDEWEB)

    Coche, E.E.; Hammer, F.D.; Goffette, P.P. [Dept. of Radiology, St. Luc University Hospital, Brussels (Belgium)

    2001-11-01

    The authors report a case of successful detection of pulmonary embolism using gadolinium-enhanced spiral CT (Gadodiamide, 0.4 mmol/kg, 2 ml/s, delay 18 s) in a 77-year-old woman, with previous allergy to iodinated contrast medium, and renal failure, who presented with pulmonary arterial hypertension. Doppler ultrasound of the lower limbs was first performed and revealed a deep venous thrombosis of the right lower limb. To establish if venous thrombosis was the cause of pulmonary hypertension and to confirm that pulmonary endarterectomy was not indicated in this situation, several imaging modalities were performed. Lung scintigraphy and MRI were non-diagnostic. Gadolinium-enhanced spiral CT demonstrated a large thrombus located proximally and in a segmental artery of the right lower lobe. This case illustrates the potential usefulness of gadolinium as alternative contrast agent with spiral CT to diagnose pulmonary embolism and elucidate the cause of pulmonary arterial hypertension in a patient with some contraindications for iodinated contrast medium injection. (orig.)

  2. Demonstration of pulmonary embolism with gadolinium-enhanced spiral CT

    International Nuclear Information System (INIS)

    Coche, E.E.; Hammer, F.D.; Goffette, P.P.

    2001-01-01

    The authors report a case of successful detection of pulmonary embolism using gadolinium-enhanced spiral CT (Gadodiamide, 0.4 mmol/kg, 2 ml/s, delay 18 s) in a 77-year-old woman, with previous allergy to iodinated contrast medium, and renal failure, who presented with pulmonary arterial hypertension. Doppler ultrasound of the lower limbs was first performed and revealed a deep venous thrombosis of the right lower limb. To establish if venous thrombosis was the cause of pulmonary hypertension and to confirm that pulmonary endarterectomy was not indicated in this situation, several imaging modalities were performed. Lung scintigraphy and MRI were non-diagnostic. Gadolinium-enhanced spiral CT demonstrated a large thrombus located proximally and in a segmental artery of the right lower lobe. This case illustrates the potential usefulness of gadolinium as alternative contrast agent with spiral CT to diagnose pulmonary embolism and elucidate the cause of pulmonary arterial hypertension in a patient with some contraindications for iodinated contrast medium injection. (orig.)

  3. Gadolinium enhances the sensitivity of SW-1573 cells for thermal neutron irradiation

    NARCIS (Netherlands)

    Franken, N. A. P.; Bergs, J. W. J.; Kok, T. T.; Kuperus, R. R. N.; Stecher-Rasmussen, F.; Haveman, J.; van Bree, C.; Stalpers, L. J. A.

    2006-01-01

    Gadolinium neutron capture therapy (Gd-NCT) is an experimental cancer treatment based on the physical principal that neutron capture by gadolinium-157 ensures the release of focal high-dose radiation, such as gamma-rays and electrons. Survival and induction of chromosomal aberrations of human

  4. Glioblastoma, gadolinium (III) and NCT. An in vitro study

    International Nuclear Information System (INIS)

    Mercanti, D.; Casalbore, P.; Sanita, F.; Rosi, F.; Festinesi, A.; Pallini, R.; Gilbert, B.; Stasio, G. de

    2000-01-01

    We treated cultured human glioblastoma cells with gadolinium (III) [gadopentetic acid] and we found that: a) cells do internalise this element; b) gadolinium can be localised in the cells nuclei; c) exposure of the cultures to a neutron beam produced a significant and immediate cell death. Although cell survival was also influenced in the irradiated controls it was further reduced (about 50%) in cells pre-exposed to 10 mg/ml gadopentetic acid. We also found that Gd uptake, as measured by ICP-AES, was concentration dependent. (author)

  5. Feasibility and accuracy of dual-layer spectral detector computed tomography for quantification of gadolinium: a phantom study.

    Science.gov (United States)

    van Hamersvelt, Robbert W; Willemink, Martin J; de Jong, Pim A; Milles, Julien; Vlassenbroek, Alain; Schilham, Arnold M R; Leiner, Tim

    2017-09-01

    The aim of this study was to evaluate the feasibility and accuracy of dual-layer spectral detector CT (SDCT) for the quantification of clinically encountered gadolinium concentrations. The cardiac chamber of an anthropomorphic thoracic phantom was equipped with 14 tubular inserts containing different gadolinium concentrations, ranging from 0 to 26.3 mg/mL (0.0, 0.1, 0.2, 0.4, 0.5, 1.0, 2.0, 3.0, 4.0, 5.1, 10.6, 15.7, 20.7 and 26.3 mg/mL). Images were acquired using a novel 64-detector row SDCT system at 120 and 140 kVp. Acquisitions were repeated five times to assess reproducibility. Regions of interest (ROIs) were drawn on three slices per insert. A spectral plot was extracted for every ROI and mean attenuation profiles were fitted to known attenuation profiles of water and pure gadolinium using in-house-developed software to calculate gadolinium concentrations. At both 120 and 140 kVp, excellent correlations between scan repetitions and true and measured gadolinium concentrations were found (R > 0.99, P  0.99, CI 0.99-1.00). Relative mean measurement errors stayed below 10% down to 2.0 mg/mL true gadolinium concentration at 120 kVp and below 5% down to 1.0 mg/mL true gadolinium concentration at 140 kVp. SDCT allows for accurate quantification of gadolinium at both 120 and 140 kVp. Lowest measurement errors were found for 140 kVp acquisitions. • Gadolinium quantification may be useful in patients with contraindication to iodine. • Dual-layer spectral detector CT allows for overall accurate quantification of gadolinium. • Interscan variability of gadolinium quantification using SDCT material decomposition is excellent.

  6. Microwave and optical diagnostics in a gadolinium plasma

    International Nuclear Information System (INIS)

    Larousse, B.

    1997-01-01

    The optimization of the separation process of the gadolinium isotopes by Ion Cyclotron Resonance requires a precise knowledge of the physical characteristics of the plasma. Thus, two kinds of diagnostics have been developed: the first one to estimate the microwave power inside the source and the second one to measure the density of atomic and ionic of the gadolinium inside the plasma source and in front of the collector. Microwave diagnostic: A microstrip antenna has been designed and developed in order to characterize the microwave at 36 GHz frequency in the plasma source. The experimental results for different plasma regimes are presented. The measurements inside the plasma source show a maximum of microwave absorption for an argon pressure of 10 -4 mb (93% of absorption of the incident wave in the conditions of isotope separation). Laser absorption diagnostic: The theory of laser absorption in presence of a magnetic field is recalled and the first results are presented. In the spectral range between 560 and 620 nm, corresponding to high energy levels of gadolinium, no signal is obtained so that the density is below the detection limit 10 10 cm -3 . In the spectral range between 380 and 400 nm, two lines are observed, issue from the fundamental and metastable (633 cm -1 ) levels. The density of metastable level of gadolinium ions is about 10 10 cm -3 with a relative precision of 15 % and its variation is studied as a function of argon pressure, at different sections of the plasma column (source, collector). The achieved set of measurements has been performed in order to check the theoretical models. (author)

  7. Isotope shift studies in gadolinium spectra

    International Nuclear Information System (INIS)

    Ahmad, S.A.; Saksena, G.D.; Venugopalan, A.

    1976-01-01

    Isotope shift studies have been carried out in the gadolinium spectrum using a recording Fabry-Perot spectrometer and gadolinium samples enriched in 156 Gd and 160 Gd isotopes. Isotope shifts Δsigma(156-160) have been recorded in 134 lines in the region 3930-4140 A. Some of these lines involve the recently identified even configuration 4f 8 5d6s of Gd I and the newly classified transition 4f 8 6s-4f 8 6p of Gd II. From the isotope shift measurements of lines involving the 4f 8 6s-4f 8 6p transition in Gd II, the isotope shift, ΔT(156-160)=87 mK, has been obtained for the 4f 8 6s configuration. Electronic configurations have been suggested for a number of energy levels and configuration mixing has been pointed out in certain cases. (Auth.)

  8. Characteristics of Gadolinium Oxide Nanoparticles Using Terahertz Spectroscopy

    International Nuclear Information System (INIS)

    Lee, Dongkyu; Maeng, Inhee; Son, Joo-Hiuk; Oh, Seung Jae; Kim, Taekhoon; Cho, Byung Kyu; Lee, Kwangyeol

    2009-01-01

    The penetration property of the terahertz electromagnetic (THz) wave is relevant to its use. We used the THz wave spectroscopy system which easily penetrates some materials that do not contain water, e.g., plastic and ceramics. The system has been developed for several purposes, including measuring the properties of semiconductors and bio-materials, and detecting plastic bombs and ceramic knives at airports. It is also used for medical imaging systems, such as magnetic resonance imaging (MRI), at some research institutes. It can show not only the difference in amplitude, but also the difference of the phase of each point of sample. MRI technology usually uses contrast agents to enhance the quality of the image. Gadolinium diethylenetriamine pentaacetic acid (Gd-DTPA), made with a heavy metal ion, is commonly used as a clinical MRI contrast agent. Gadolinium oxide (Gd 2 O 3 ) nanoparticle is a new contrast agent. It serves to equip the core of each particle with antibodies or ligands. It can freely circulate in blood vessels without amassing in the liver or lungs. This study shows the characteristics of gadolinium oxide nanoparticles to further advance terahertz medical imaging.

  9. Influence of the addition of gadolinium on the microstructure and mechanical properties of duplex stainless steel

    International Nuclear Information System (INIS)

    Ahn, Ji-Ho; Jung, Hyun-Do; Im, Jae-Han; Jung, Ki Ho; Moon, Byung-Moon

    2016-01-01

    The aim of this study is to investigate the effects of gadolinium addition on the microstructure and mechanical properties of duplex stainless steel (DSS) fabricated using a normal casting method. The oxygen content in the cast DSS alloy with gadolinium decreased because of the high reactivity of gadolinium with oxygen. The area fraction and size of non-intermetallic inclusions in the alloy decreased from 0.80±0.12% to 0.58±0.04% and from 6.9±0.7 to 5.8±0.4 μm upon gadolinium addition, respectively. Notably, the ultimate tensile strength and strain at break of the cast alloy significantly increased with the addition of gadolinium from 919±25 to 969±8 MPa and from 24.8±1.9% to 28.4±1.1%, respectively. The hardness of the cast alloy with gadolinium increased from 23.6±1.3 to 25.0±1.2 HRC. A significant increase in the impact energy of the cast alloy was observed and the brittle-to-ductile transition temperature slightly decreased by approximately 10 °C with the addition of gadolinium.

  10. Reaction of ammonium triphosphate with gadolinium nitrate in aqueous solution at 273K

    International Nuclear Information System (INIS)

    Rodicheva, G.V.; Tananaev, I.V.; Romanova, N.M.

    1982-01-01

    The solubility in the system (NW 4 ) 5 P 3 O 10 -Gd(NO 3 ) 3 - H 2 O (273 K) is studied. Depending on the reagent ratio formation of the compounds Gd 5 (P 3 O 10 ) 3 x22H 2 O, NH 4 Gd 3 (P 3 O 10 ) 2 x12H 2 O and (NH 4 ) 3 Gd 4 (P 3 O 10 ) 3 x14H 2 O is established. Gadolinium triphosphates, separated from solution, are studied using the methods of paper chromatography, X-ray diffractometry, thermography. Simultaneously with thermal dehydration of gadolinium triphosphates the processes of triphosphate decomposition and phosphate anion condensation take place. A mixture of crystalline ortho-phosphate and long- chain polyphosphate of gadolinium is the final product of thermal decomposition (1063 K) of normal and doubl e ammonium- containing gadolinium triphosphates [ru

  11. Gadolinium-enhanced MR angiography (Gd-MRA) of thoracic vasculature in an animal model using double-dose gadolinium and quiet breathing

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez, R.J.; Strouse, P.J. [Section of Pediatric Radiology, University of Michigan Health System, Ann Arbor (United States); Londy, F.J. [Dept. of Radiology, University of Michigan Hospitals, Ann Arbor, MI (United States); Wakefield, T.W. [Dept. of Surgery, Section of Vascular Surgery, University of Michigan Hospitals, Ann Arbor, MI (United States)

    2001-08-01

    Objective. To evaluate a gadolinium-enhanced MR angiography (Gd-MRA) imaging protocol for the assessment of thoracic vessels using double-dose gadolinium and quiet breathing. An animal model was used to simulate imaging in infants and young children. Material and methods. Six baboons (Papio anubis), mean weight 5.7 kg, were sedated and intubated. After the injection of double-dose Gd-DTPA (0.2 mmol/kg) through a peripheral vein, a coronal spoiled 3D gradient-echo volume acquisition was obtained during quiet breathing. Two radiologists reviewed the images for visualization of aortic arch, brachiocephalic vessel origins, pulmonary arteries (central, upper lobe and descending branches), and pulmonary veins (upper and lower). Results. Visualization was excellent for the aortic arch, brachiocephalic vessel origins, and pulmonary arteries, including the hilar branches. Visualization was excellent for the lower and right upper pulmonary veins and fair for the left upper pulmonary vein. There was excellent agreement between radiologists. Conclusion. Imaging of thoracic vessels with Gd-MRA using double gadolinium during quiet breathing was effective in our animal model. The advantages of this technique include a short imaging time and depiction of vascular segments - branches of pulmonary arteries and intraparenchymal segments of pulmonary veins - not optimally visualized with other non-invasive imaging techniques. (orig.)

  12. Gadolinium-enhanced MR angiography (Gd-MRA) of thoracic vasculature in an animal model using double-dose gadolinium and quiet breathing

    International Nuclear Information System (INIS)

    Hernandez, R.J.; Strouse, P.J.; Londy, F.J.; Wakefield, T.W.

    2001-01-01

    Objective. To evaluate a gadolinium-enhanced MR angiography (Gd-MRA) imaging protocol for the assessment of thoracic vessels using double-dose gadolinium and quiet breathing. An animal model was used to simulate imaging in infants and young children. Material and methods. Six baboons (Papio anubis), mean weight 5.7 kg, were sedated and intubated. After the injection of double-dose Gd-DTPA (0.2 mmol/kg) through a peripheral vein, a coronal spoiled 3D gradient-echo volume acquisition was obtained during quiet breathing. Two radiologists reviewed the images for visualization of aortic arch, brachiocephalic vessel origins, pulmonary arteries (central, upper lobe and descending branches), and pulmonary veins (upper and lower). Results. Visualization was excellent for the aortic arch, brachiocephalic vessel origins, and pulmonary arteries, including the hilar branches. Visualization was excellent for the lower and right upper pulmonary veins and fair for the left upper pulmonary vein. There was excellent agreement between radiologists. Conclusion. Imaging of thoracic vessels with Gd-MRA using double gadolinium during quiet breathing was effective in our animal model. The advantages of this technique include a short imaging time and depiction of vascular segments - branches of pulmonary arteries and intraparenchymal segments of pulmonary veins - not optimally visualized with other non-invasive imaging techniques. (orig.)

  13. Growth, characterization and dielectric studies of gadolinium ...

    Indian Academy of Sciences (India)

    solution of higher pH. After complete gelation, an .... between the gadolinium and fumarate ions because at higher ..... Department of Higher Education, Government of Jammu and. Kashmir, for providing and facilitating the teacher fellowship.

  14. Modeling gadolinium-bearing fuel in Ringhals PWRs using CASMO/SIMULATE

    International Nuclear Information System (INIS)

    Kurcyusz, E.

    1993-01-01

    Ringhals units 2, 3, and 4 are Westinghouse three-loop, 157-assembly pressurized water reactors (PWRs) operated by Vattenfall. Originally, all three reactors were loaded in an out-in scheme using reload fuel without burnable poisons. In recent cycles, gadolinium-bearing fuel was introduced to enable a low-leakage loading pattern and minimize fuel cycle costs. This paper focuses on the Fragema 17 x 17 AFA design with peripheral gadolinium rods loaded in units 3 and 4. The Ringhals units are modeled using the Studsvik core management system, consisting of the CASMO-3 transport theory lattice physics code,and the SIMULATE-3 advanced nodal reactor analysis code. The results of the studies verifying the accuracy of CASMO-3/SIMULATE-3 on the assemblies with peripheral gadolinium rods are presented in this paper. The verification was carried out against CASMO-3 color-set calculations and measured reactor data

  15. Synthesis and characterization of rare-earth-doped calcium tungstate nanocrystals

    Science.gov (United States)

    Suneeta, P.; Rajesh, Ch.; Ramana, M. V.

    2018-02-01

    In this paper, we report synthesis and characterization of rare-earth-ion-doped calcium tungstate (CaWO4) nanocrystals (NCs). Rare-earth ions, such as gadolinium (Gd), neodymium (Nd), praseodymium (Pr), samarium (Sm) and holmium (Ho), were successfully doped in the CaWO4 NCs by changing the synthesis conditions. The adopted synthesis route was found to be fast and eco-friendly. Structural characterizations, such as X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and compositional analysis, were performed using energy dispersive analysis of X-rays (EDAX) on as-synthesized NCs. The results indicate the size of the NCs ranging between 47 to 68nm and incorporation of rare-earth ions in CaWO4 NCs.

  16. Spectral, Electrochemical, Fluorescence, Kinetic and Anti-microbial Studies of Acyclic Schiff-base Gadolinium(III) Complexes

    International Nuclear Information System (INIS)

    Vijayaraj, A.; Prabu, R.; Suresh, R.; Narayanan, V.; Sangeetha Kumari, R.; Kaviyarasan, V.

    2012-01-01

    A new series of acyclic mononuclear gadolinium(III) complexes have been prepared by Schiff-base condensation derived from 5-methylsalicylaldehyde, diethylenetriamine, tris(2-aminoethyl) amine, triethylenetetramine, N,N-bis(3-aminopropyl)ethylene diamine, N,N-bis(aminopropyl) piperazine, and gadolinium nitrate. All the complexes were characterized by elemental and spectral analyses. Electronic spectra of the complexes show azomethine (CH=N) within the range of 410-420 nm. The fluorescence efficiency of Gd(III) ion in the cavity was completely quenched by the higher chain length ligands. Electrochemical studies of the complexes show irreversible one electron reduction process around -2.15 to -1.60 V. The reduction potential of gadolinium(III) complexes shifts towards anodic directions respectively upon increasing the chain length. The catalytic activity of the gadolinium(III) complexes on the hydrolysis of 4-nitrophenylphosphate was determined. All gadolinium(III) complexes were screened for antibacterial activity

  17. Spectral, Electrochemical, Fluorescence, Kinetic and Anti-microbial Studies of Acyclic Schiff-base Gadolinium(III) Complexes

    Energy Technology Data Exchange (ETDEWEB)

    Vijayaraj, A.; Prabu, R.; Suresh, R.; Narayanan, V.; Sangeetha Kumari, R.; Kaviyarasan, V. [Univ. of Madras, Madras (India)

    2012-11-15

    A new series of acyclic mononuclear gadolinium(III) complexes have been prepared by Schiff-base condensation derived from 5-methylsalicylaldehyde, diethylenetriamine, tris(2-aminoethyl) amine, triethylenetetramine, N,N-bis(3-aminopropyl)ethylene diamine, N,N-bis(aminopropyl) piperazine, and gadolinium nitrate. All the complexes were characterized by elemental and spectral analyses. Electronic spectra of the complexes show azomethine (CH=N) within the range of 410-420 nm. The fluorescence efficiency of Gd(III) ion in the cavity was completely quenched by the higher chain length ligands. Electrochemical studies of the complexes show irreversible one electron reduction process around -2.15 to -1.60 V. The reduction potential of gadolinium(III) complexes shifts towards anodic directions respectively upon increasing the chain length. The catalytic activity of the gadolinium(III) complexes on the hydrolysis of 4-nitrophenylphosphate was determined. All gadolinium(III) complexes were screened for antibacterial activity.

  18. Follicle-stimulating hormone receptor-mediated uptake of 45Ca2+ by proteoliposomes and cultured rat sertoli cells: Evidence for involvement of voltage-activated and voltage-independent calcium channels

    International Nuclear Information System (INIS)

    Grasso, P.; Reichert, L.E. Jr.

    1989-01-01

    We have previously reported incorporation into liposomes of Triton X-100-solubilized FSH receptor-G-protein complexes derived from purified bovine calf testis membranes. In the present study we have used this model system to show that FSH induces flux of 45Ca2+ into such proteoliposomes in a hormone-specific concentration-dependent manner. FSH, inactivated by boiling, had no stimulatory effect on 45Ca2+ flux, nor did isolated alpha- or beta-subunits of FSH. Addition of GTP (or its analogs 5'-guanylylimidodiphosphate and guanosine-5'-O-[3-thiotriphosphate]) or sodium fluoride (in the presence or absence of GTP or its analogs) failed to induce 45Ca2+ flux into proteoliposomes, suggesting that the uptake of 45Ca2+ was receptor, and not G-protein, related. Voltage-independent (ruthenium red and gadolinium chloride) and voltage-activated (methyoxyverapamil and nifedipine) calcium channel-blocking agents reduced FSH-stimulated 45Ca2+ flux into proteoliposomes to control levels. FSH also induced uptake of 45Ca2+ by cultured rat Sertoli cells. Ruthenium red and gadolinium chloride had no effect on basal levels of 45Ca2+ uptake or estradiol secretion by cultured rat Sertoli cells, nor did methoxyverapamil or nifedipine. All four calcium channel blockers, however, were able to reduce FSH-induced 45Ca2+ uptake to basal levels and FSH-stimulated conversion of androstenedione to estradiol by up to 50%, indicating an involvement of Ca2+ in FSH-stimulated steroidogenesis. Our results suggest that the well documented changes in intracellular calcium levels consequent to FSH binding may be due, at least in part, to an influx of calcium through FSH receptor-regulated calcium channels

  19. Solitary hepatic infantile hemangioendothelioma: dynamic gadolinium-enhanced MR imaging findings

    International Nuclear Information System (INIS)

    Mortele, Koenraad J.; Vanzieleghem, Bart; Mortele, Bart; Benoit, Yves; Ros, Pablo R.

    2002-01-01

    We report the MRI findings of a solitary hepatic infantile hemangioendothelioma (IHE) diagnosed in a 14-day-old girl. To the best of our knowledge, only one report has illustrated the dynamic gadolinium-enhanced MR imaging features of IHE previously. Compounding the rarity of presentation as a solitary mass, the gadolinium-enhanced MRI appearance in our case is unique, because the IHE showed an early rim-like pseudocapsular enhancement followed by progressive fill-in of the lesion on delayed imaging. (orig.)

  20. Gadolinium-based contrast agents in pediatric magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Gale, Eric M.; Caravan, Peter [Massachusetts General Hospital, Harvard Medical School, Department of Radiology, The Martinos Center for Biomedical Imaging, Boston, MA (United States); Rao, Anil G. [Medical University of South Carolina, Department of Radiology and Radiological Science, Charleston, SC (United States); McDonald, Robert J. [College of Medicine, Mayo Clinic, Department of Radiology, Rochester, MN (United States); Winfeld, Matthew [University of Pennsylvania Perelman School of Medicine, Philadelphia, PA (United States); Fleck, Robert J. [Cincinnati Children' s Hospital Medical Center, Department of Pediatric Radiology, Cincinnati, OH (United States); Gee, Michael S. [MassGeneral Hospital for Children, Harvard Medical School, Division of Pediatric Imaging, Department of Radiology, Boston, MA (United States)

    2017-05-15

    Gadolinium-based contrast agents can increase the accuracy and expediency of an MRI examination. However the benefits of a contrast-enhanced scan must be carefully weighed against the well-documented risks associated with administration of exogenous contrast media. The purpose of this review is to discuss commercially available gadolinium-based contrast agents (GBCAs) in the context of pediatric radiology. We discuss the chemistry, regulatory status, safety and clinical applications, with particular emphasis on imaging of the blood vessels, heart, hepatobiliary tree and central nervous system. We also discuss non-GBCA MRI contrast agents that are less frequently used or not commercially available. (orig.)

  1. Gadolinium Use in Spine Pain Management Procedures for Patients with Contrast Allergies: Results in 527 Procedures

    International Nuclear Information System (INIS)

    Safriel, Yair; Ang, Roberto; Ali, Muhammed

    2008-01-01

    Introduction. To review the safety and efficacy of gadolinium in spine pain management procedures in patients at high risk for a contrast reaction and who are not suitable candidates for the use of standard non-ionic contrast. Methods. We reviewed records over a 61-month period of all image-guided spinal pain management procedures where patients had allergies making them unsuitable candidates for standard non-ionic contrast and where gadolinium was used to confirm needle tip placement prior to injection of medication. Results. Three hundred and four outpatients underwent 527 procedures. A spinal needle was used in all but 41 procedures. Gadolinium was visualized using portable C-arm fluoroscopy in vivo allowing for confirmation of needle tip location. The gadolinium dose ranged from 0.2 to 10 ml per level. The highest dose received by one patient was 15.83 ml intradiscally during a three-level discogram. Three hundred and one patients were discharged without complication or known delayed complications. One patient had documented intrathecal injection but without sequelae and 2 patients who underwent cervical procedures experienced seizures requiring admission to the intensive care unit. Both the latter patients were discharged without any further complications. Conclusion. Based on our experience we recommend using gadolinium judiciously for needle tip confirmation. We feel more confident using gadolinium in the lumbar spine and in cervical nerve blocks. Gadolinium should probably not be used as an injectate volume expander. The indications for gadolinium use in cervical needle-guided spine procedures are less clear and use of a blunt-tipped needle should be considered

  2. Bone marrow blood supply in gadolinium-enhanced magnetic resonance imaging

    International Nuclear Information System (INIS)

    Saifuddin, A.; Bann, K.; Ridgway, J.P.; Butt, W.P.

    1994-01-01

    A retrospective study was performed to determine whether bone blood supply can be assessed on gadolinium-enhanced magnetic resonance imaging. Lumbar spine magnetic resonance imaging (MRI) examinations of 49 patients attending for post-laminectomy examination were reviewed (30 male, 19 female, mean age 46.4 years, age range 23-84 years). Each study included sagittal T1-weighted spin echo sequences before and after gadolinium administration. Regions of interest were drawn within the L3 vertebral body from a parasagittal slice from each sequence. Signal intensity (SI) values were ascertained and the percentage increase in SI was calculated. For each patient, changes in receiver gain for pre- and post-gadolinium images were corrected by an image scaling factor. In all cases, a measurable increase in SI was found (mean 15.3%, range 4.4-55.7) due to bone vascularity. The results give no indication of the quantity or timing of blood supply but provide a basis for further work. (orig.)

  3. Gadolinium-DTPA-enhanced magnetic resonance imaging of musculoskeletal infectious processes

    International Nuclear Information System (INIS)

    Hopkins, K.L.; Li, K.C.P.; Bergman, G.

    1995-01-01

    The purpose of this study was to assess whether gadolinium-enhanced magnetic resonance imaging (MRI) provides diagnostic information beyond that given by nonenhanced imaging in the evaluation of musculoskeletal infectious processes and whether it can be used for differentiating infectious from noninfectious inflammatory lesions. Magnetic resonance images performed with and without intravenous gadolinium-DTPA in 34 cases in which musculoskeletal infection had been clinically suspected were reviewed. Infectious lesions-including osteomyelitis, pyarthrosis, abscess, and cellulitis-were confirmed in a total of 22 cases: in 15 by biopsy or drainage and in 7 by clinical course. Our results show that gadolinium-DTPA-enhanced MRI is a highly sensitive technique in diagnosing musculoskeletal infectious lesions. It is especially useful in distinguishing abscesses from surrounding cellulitis/myositis. Lack of contrast enhancement rules out infection with a high degree of certainty. However, contrast enhancement cannot be used to reliably distinguish infectious from noninfectious inflammatory conditions. (orig.)

  4. Gadolinium-DTPA-enhanced magnetic resonance imaging of musculoskeletal infectious processes

    Energy Technology Data Exchange (ETDEWEB)

    Hopkins, K.L. [Dept. of Diagnostic Radiology, Stanford Univ. Medical Center, CA (United States); Li, K.C.P. [Dept. of Diagnostic Radiology, Stanford Univ. Medical Center, CA (United States); Bergman, G. [Dept. of Diagnostic Radiology, Stanford Univ. Medical Center, CA (United States)

    1995-07-01

    The purpose of this study was to assess whether gadolinium-enhanced magnetic resonance imaging (MRI) provides diagnostic information beyond that given by nonenhanced imaging in the evaluation of musculoskeletal infectious processes and whether it can be used for differentiating infectious from noninfectious inflammatory lesions. Magnetic resonance images performed with and without intravenous gadolinium-DTPA in 34 cases in which musculoskeletal infection had been clinically suspected were reviewed. Infectious lesions-including osteomyelitis, pyarthrosis, abscess, and cellulitis-were confirmed in a total of 22 cases: in 15 by biopsy or drainage and in 7 by clinical course. Our results show that gadolinium-DTPA-enhanced MRI is a highly sensitive technique in diagnosing musculoskeletal infectious lesions. It is especially useful in distinguishing abscesses from surrounding cellulitis/myositis. Lack of contrast enhancement rules out infection with a high degree of certainty. However, contrast enhancement cannot be used to reliably distinguish infectious from noninfectious inflammatory conditions. (orig.)

  5. The use of iodinated and gadolinium contrast media during pregnancy and lactation

    Energy Technology Data Exchange (ETDEWEB)

    Webb, Judith A.W. [St. Bartholomew' s Hospital, Department of Diagnostic Imaging, London (United Kingdom); Thomsen, Henrik S. [Copenhagen University Hospital at Herlev, Department of Diagnostic Radiology 54E2, Herlev (Denmark); Morcos, Sameh K. [Northern General Hospital, Department of Diagnostic Imaging, Sheffield (United Kingdom)

    2005-06-01

    The use of iodinated or gadolinium-based contrast media in pregnant or lactating women often causes concerns in the radiology department because of the principle of not exposing a fetus or neonate to any drugs. Because of the uncertainty about the use of contrast media during pregnancy and lactation, the Contrast Media Safety Committee of the European Society of Urogenital Radiology decided to review the literature and draw up guidelines. An extensive literature search was carried out and summarized in a report. Based on the limited information available, simple guidelines have been drawn up. The report and guidelines were discussed at the 11th European Symposium on Urogenital Radiology in Santiago de Compostela, Spain. Mutagenic and teratogenic effects have not been described after administration of gadolinium or iodinated contrast media. Free iodide in radiographic contrast medium given to the mother has the potential to depress fetal/neonatal thyroid function. Neonatal thyroid function should be checked during the 1st week if iodinated contrast media have been given during pregnancy. No effect on the fetus has been seen after gadolinium contrast media. Only tiny amounts of iodinated or gadolinium-based contrast medium given to a lactating mother reach the milk, and only a minute proportion entering the baby's gut is absorbed. The very small potential risk associated with absorption of contrast medium may be considered insufficient to warrant stopping breast-feeding for 24 h following either iodinated or gadolinium contrast agents. (orig.)

  6. The use of iodinated and gadolinium contrast media during pregnancy and lactation

    International Nuclear Information System (INIS)

    Webb, Judith A.W.; Thomsen, Henrik S.; Morcos, Sameh K.

    2005-01-01

    The use of iodinated or gadolinium-based contrast media in pregnant or lactating women often causes concerns in the radiology department because of the principle of not exposing a fetus or neonate to any drugs. Because of the uncertainty about the use of contrast media during pregnancy and lactation, the Contrast Media Safety Committee of the European Society of Urogenital Radiology decided to review the literature and draw up guidelines. An extensive literature search was carried out and summarized in a report. Based on the limited information available, simple guidelines have been drawn up. The report and guidelines were discussed at the 11th European Symposium on Urogenital Radiology in Santiago de Compostela, Spain. Mutagenic and teratogenic effects have not been described after administration of gadolinium or iodinated contrast media. Free iodide in radiographic contrast medium given to the mother has the potential to depress fetal/neonatal thyroid function. Neonatal thyroid function should be checked during the 1st week if iodinated contrast media have been given during pregnancy. No effect on the fetus has been seen after gadolinium contrast media. Only tiny amounts of iodinated or gadolinium-based contrast medium given to a lactating mother reach the milk, and only a minute proportion entering the baby's gut is absorbed. The very small potential risk associated with absorption of contrast medium may be considered insufficient to warrant stopping breast-feeding for 24 h following either iodinated or gadolinium contrast agents. (orig.)

  7. ICP-oa TOFMS utilisation to determine the Gd isotopic abundance in gadolinium nitrate

    International Nuclear Information System (INIS)

    Dragomir, M.; Ohai, D.; Dumitrescu, I.; Furtuna, I.

    2010-01-01

    This paper is describes the development of a method that should permit the determination of isotope abundance of gadolinium in gadolinium nitrate, used as burnable poison at Cernavoda NPP. To determine the isotopic abundance of gadolinium the inductively coupled plasma orthogonal acceleration time-of-flight mass spectrometer (ICP-oa TOFMS) was used. The ICP-oa TOFMS allows the elimination of noise associated with instrumental drift and instability (flicker noise). The absence of flicker noise in the ICP-oa TOFMS means that the isotope ratios can be measured up to the statistical limit of ion counting. With TOFMS, each spectrum acquired represents signals from ions extracted from the plasma during the same time interval, formed from identical plasma and sample introduction events. Therefore, the ICP-oa TOFMS, Optimass 8000, has been successfully used for isotope ratio measurements of Gd in gadolinium nitrate [Gd (NO 3 ) 3 x 6H 2 O] sample solutions. (authors)

  8. Correlation between late gadolinium enhancement and diastolic function in hypertrophic cardiomyopathy assessed by magnetic resonance imaging

    International Nuclear Information System (INIS)

    Motoyasu, Munenobu; Kurita, Tairo; Onishi, Katsuya

    2008-01-01

    Diastolic dysfunction is common in patients with overt hypertrophic cardiomyopathy (HCM). Steady-state cine magnetic resonance imaging (MRI) enables measurement of the diastolic function of the left ventricle (LV), and late gadolinium enhanced MRI can delineate the presence and extent of fibrosis in HCM. The purpose of this study was to determine the relationship between the extent of myocardial fibrosis demonstrated by late gadolinium-enhanced MRI and diastolic dysfunction. Seventeen patients (13 men, mean age 57.7±9.8 years) with HCM were studied. The severity index of late gadolinium enhancement was determined by scoring the extent of enhanced tissue in 30 myocardial segments. The peak filling rate (PFR), LV ejection fraction and LV mass were determined by cine MRI. Contrast-enhanced MRI demonstrated late gadolinium enhancement in 97 of 510 segments (19%) and 13 of the 17 patients (77%). The severity index of late gadolinium enhancement demonstrated a significant negative correlation with PFR (r=-0.86, p<0.01) and with the LV ejection fraction (r=-0.59, p<0.05). No significant correlation was observed between the severity index of late gadolinium enhancement and LV mass (r=0.23, p=0.30). The extent of myocardial fibrosis revealed by late gadolinium-enhanced MRI has a strong relationship to diastolic dysfunction in patients with HCM. (author)

  9. MR arthrography gadolinium versus standard MR imaging in rotator cuff pathology

    International Nuclear Information System (INIS)

    Hodler, J.; Brahme, S.K.; Karzel, R.; Cervilla, V.; Snyder, S.; Schweitzer, M.; Flannigan, B.; Resnick, D.

    1990-01-01

    This paper compares the accuracy of MR imaging with and without intraarticular gadolinium in the diagnosis of rotator cuff pathology, using arthroscopy as the gold standard. The authors examined 36 patients, first with T2-weighted sequences and then with T1-weighted sequences after the injection of 15-20 mL of diluted gadolinium. The images were read blindly by three radiologists experienced in musculoskeletal MR imaging. The results were compared with those of arthroscopy. In 16 of 19 arthroscopically intact rotator cuffs, both sequences demonstrated no evidence of rotator cuff tear. The remaining three cases were interpreted as partial or full-thickness tears. Of 12 partial tears, T1-weighted images with intraarticular gadolinium demonstrated a partial tear in five, degeneration in four, a full thickness tear in two, and a normal rotator cuff in one

  10. Experimental determination of electron shock excitation cross sections for a singly charged gadolinium ion

    International Nuclear Information System (INIS)

    Smirnov, Yu.M.

    1995-01-01

    The trends observed in the processes of excitation with simultaneous ionization have received little study. This is particularly so for rare-earth elements having electron shells of complex structure and optical spectra very rich in lines. Among the basic factors responsible for such a situation, we should mention two: the difficulty presented by theoretical analysis of the processes discussed and the absence of factual information about the excitation cross sections with simultaneous ionization for the majority of rare-earth elements. The aim of the present work is to investigate the excitation of a singly charged gadolinium ion in the collisions of monokinetic electrons with gadolinium atoms. Up to the present time, only the excitation cross sections of a gadolinium atom have been measured, where investigation of the electron shock excitation of gadolinium atoms in their free state is associated with overcoming large experimental difficulties. About 160 crosss sections for the excitation of a singly charged gadolinium ion were measured and for a third of the cross sections; the energy dependences were recorded for the change in energy of the elecrons from the excitation threshold up to 200 eV. Included are tables of the wavelength, transistion, internal quantum number, the energy of the lowere and upper levels, and the values of cross sections for the charged gadolinium ion. Diagrams of the transistion energy states of Gd (II) and spectroscopy are presented and explained

  11. Purification of cerium, neodymium and gadolinium for low background experiments

    Directory of Open Access Journals (Sweden)

    Boiko R.S.

    2014-01-01

    Full Text Available Cerium, neodymium and gadolinium contain double beta active isotopes. The most interesting are 150Nd and 160Gd (promising for 0ν2β search, 136Ce (2β+ candidate with one of the highest Q2β. The main problem of compounds containing lanthanide elements is their high radioactive contamination by uranium, radium, actinium and thorium. The new generation 2β experiments require development of methods for a deep purification of lanthanides from the radioactive elements. A combination of physical and chemical methods was applied to purify cerium, neodymium and gadolinium. Liquid-liquid extraction technique was used to remove traces of Th and U from neodymium, gadolinium and for purification of cerium from Th, U, Ra and K. Co-precipitation and recrystallization methods were utilized for further reduction of the impurities. The radioactive contamination of the samples before and after the purification was tested by using ultra-low-background HPGe gamma spectrometry. As a result of the purification procedure the radioactive contamination of gadolinium oxide (a similar purification efficiency was reached also with cerium and neodymium oxides was decreased from 0.12 Bq/kg to 0.007 Bq/kg in 228Th, from 0.04 Bq/kg to <0.006 Bq/kg in 226Ra, and from 0.9 Bq/kg to 0.04 Bq/kg in 40K. The purification methods are much less efficient for chemically very similar radioactive elements like actinium, lanthanum and lutetium.

  12. Effect of hydrostatic pressure on magnetic phase transitions and magnetization in gadolinium monocrystal

    International Nuclear Information System (INIS)

    Nikitin, S.A.; Bezdushnyj, R.V.

    1989-01-01

    Effect of hydrostatic pressure on magnetization in gadolinium monocrystal (Δσ-effect) was investigated. Dependences of spesific magnetization, Δσ-effect and bulk magnetostriction of gadolinium monocrystal on temperatures were studied. Results of conducted investigation have shown that in gadolinium the change of specific magnetization under the hydrostatic pressure effect is caused in general case by three effects: a)change of spontaneous magnetization under the effect of hydrostatic pressure; b)change of magnetization within technical magnetization range due to the effect of hydrostatic pressure on magnetic anisotropy constants; c)change of magnetization due to the effect of hydrostatic pressure on temperature of spin-reoriented transition

  13. Characteristics of Gadolinium Oxide Nanoparticles Using Terahertz Spectroscopy (abstract)

    Science.gov (United States)

    Lee, Dongkyu; Maeng, Inhee; Oh, Seung Jae; Kim, Taekhoon; Cho, Byung Kyu; Lee, Kwangyeol; Son, Joo-Hiuk

    2009-04-01

    The penetration property of the terahertz electromagnetic (THz) wave is relevant to its use. We used the THz wave spectroscopy system which easily penetrates some materials that do not contain water, e.g., plastic and ceramics. The system has been developed for several purposes, including measuring the properties of semiconductors and bio-materials, and detecting plastic bombs and ceramic knives at airports. It is also used for medical imaging systems, such as magnetic resonance imaging (MRI), at some research institutes. It can show not only the difference in amplitude, but also the difference of the phase of each point of sample. MRI technology usually uses contrast agents to enhance the quality of the image. Gadolinium diethylenetriamine pentaacetic acid (Gd-DTPA), made with a heavy metal ion, is commonly used as a clinical MRI contrast agent. Gadolinium oxide (Gd2O3) nanoparticle is a new contrast agent. It serves to equip the core of each particle with antibodies or ligands. It can freely circulate in blood vessels without amassing in the liver or lungs. This study shows the characteristics of gadolinium oxide nanoparticles to further advance terahertz medical imaging.

  14. The effect of demagnetization on the magnetocaloric properties of gadolinium

    DEFF Research Database (Denmark)

    Bahl, Christian Robert Haffenden; Nielsen, Kaspar Kirstein

    2009-01-01

    of gadolinium. The adiabatic temperature change DeltaTad of gadolinium sheets upon application of a magnetic field has been measured at a range of applied magnetic fields and sample orientations. A significant dependence of DeltaTad on the sample orientation is observed. This can be accounted...... for by the demagnetization factor. Also, the temperature dependence of DeltaTad has been measured experimentally and modeled by mean field theory. Corrections to mean field theory modeling due to the demagnetization field are proposed and discussed. ©2009 American Institute of Physics...

  15. Gadolinium-enhanced MR angiography of the thoracoabdominal aorta diseases

    International Nuclear Information System (INIS)

    D'Ippolito, Giuseppe; Wolosker, Nelson; Galvao Filho, Mario; Kalil, Jorge A.; Wolosker, Angela; Borri, Maria Lucia

    1998-01-01

    Gadolinium-enhanced MR angiography (GEMRA) of the thoracoabdominal aorta is a noninvasive technique that can rapidly delineate the branch vessels diseases, without flow or respiration artifacts, obtained with non contrast MRA. The objective of this paper is to show the main clinical applications of GEMRA, compared to non contrast sequences. We have evaluated 30 patients with thorocoabdominal aorta diseases. These patients have been examined with GEMRA (3D, FFE sequences) obtained after 30 mlIV contrast injection and non contrast MRA (2D-TOF sequences). In our experience, gadolinium-enhanced MRA is a high resolution and speedy technique with advantages over non contrast MRA. (author)

  16. First experiences with the application of oral gadolinium-DTPA in MR of the minor pelvis

    International Nuclear Information System (INIS)

    Hoetzinger, H.; Salbeck, R.; Toedt, C.; Beyer, H.K.

    1990-01-01

    The use of an oral contrast medium has so far not become a matter of routine in MR of the abdomen. In the present study the use of orally applied gadolinium-DTPA was examined in respect of tumorous diseases in the minor pelvis. 18 patients with tumours in the minor pelvis were examined before and after oral administration of gadolinium-DTPA (Gd-DTPA). 10 ml/kg body weight of a gadolinium DTPA solution were applied in a concentration of 1.0 mmol/l. T 1 -weighted and T 2 -weighted sequences were carried out before application and T 1 -weighted sequences after application. Oral application of gadolinium-DTPA resulted in enhancing the signals of the filled intestinal portions. In 54% of the cases the sequences showed a sharper delineation between tumour and intestine. In 19% the delineation between pathological tissue and intestine on contrast examination was a well defined as in T 2 -weighted contrast images; in 27% of the cases oral administration of gadolinium-DTPA did not yield any additional information. No significant side effects were seen. (orig.) [de

  17. Porphyrin-containing polyaspartamide gadolinium complexes as potential magnetic resonance imaging contrast agents.

    Science.gov (United States)

    Yan, Guo-Ping; Li, Zhen; Xu, Wei; Zhou, Cheng-Kai; Yang, Lian; Zhang, Qiao; Li, Liang; Liu, Fan; Han, Lin; Ge, Yuan-Xing; Guo, Jun-Fang

    2011-04-04

    Porphyrin-containing polyaspartamide ligands (APTSPP-PHEA-DTPA) were synthesized by the incorporation of diethylenetriaminepentaacetic acid (DTPA) and 5-(4'-aminophenyl)-10,15,20-tris(4'-sulfonatophenyl) porphyrin, trisodium salt (APTSPP) into poly-α,β-[N-(2-hydroxyethyl)-l-aspartamide] (PHEA). These ligands were further reacted with gadolinium chloride to produce macromolecule-gadolinium complexes (APTSPP-PHEA-DTPA-Gd). Experimental data of (1)H NMR, IR, UV and elemental analysis evidenced the formation of the polyaspartamide ligands and gadolinium complexes. In vitro and in vivo property tests indicated that APTSPP-PHEA-DTPA-Gd possessed noticeably higher relaxation effectiveness, less toxicity to HeLa cells, and significantly higher enhanced signal intensities (SI) of the VX2 carcinoma in rabbits with lower injection dose requirement than that of Gd-DTPA. Moreover, APTSPP-PHEA-DTPA-Gd was found to greatly enhance the contrast of MR images of the VX2 carcinoma, providing prolonged intravascular duration, and distinguished the VX2 carcinoma and normal tissues in rabbits according to MR image signal enhancements. These porphyrin-containing polyaspartamide gadolinium complexes can be used as the candidates of contrast agents for targeted MRI to tumors. Crown Copyright © 2011. Published by Elsevier B.V. All rights reserved.

  18. Characterization of composite metal-ceramic of nickel-oxide cerium doped gadolinium

    International Nuclear Information System (INIS)

    Silva, M.L.A. da; Varela, M.C.R.S.

    2016-01-01

    Composite nickel doped cerium oxide are used in SOFC anode materials. In this study we evaluated the effect of the presence of gadolinium on the properties of composite nickel and ceria and. The supports were synthesized by sol-gel method. The impregnation with nickel nitrate was taken sequentially, followed by calcination. The materials were characterized by X-ray diffraction, measurement of specific surface area, temperature programmed reduction, Raman spectroscopy. The presence of gadolinium retained the fluorite structure of ceria by forming a solid solution, also not influencing significantly on the specific surface area of the support. On the other hand, there was a decrease in the area catalysts, which can be attributed to sintering of nickel. Furthermore, addition of gadolinium favored the formation of intrinsic and extrinsic vacancies in cerium oxide, which leads to an increase in the ionic conductivity of the solid, desirable property for an SOFC anode catalyst. (author)

  19. Feasibility and accuracy of dual-layer spectral detector computed tomography for quantification of gadolinium: a phantom study

    Energy Technology Data Exchange (ETDEWEB)

    Hamersvelt, Robbert W. van; Willemink, Martin J.; Jong, Pim A. de; Schilham, Arnold M.R.; Leiner, Tim [University Medical Center Utrecht, Department of Radiology, P.O. Box 85500, Utrecht (Netherlands); Milles, Julien [CT Clinical Science, Philips HealthCare, Best (Netherlands); Vlassenbroek, Alain [CT Clinical Science, Philips HealthCare, Brussels (Belgium)

    2017-09-15

    The aim of this study was to evaluate the feasibility and accuracy of dual-layer spectral detector CT (SDCT) for the quantification of clinically encountered gadolinium concentrations. The cardiac chamber of an anthropomorphic thoracic phantom was equipped with 14 tubular inserts containing different gadolinium concentrations, ranging from 0 to 26.3 mg/mL (0.0, 0.1, 0.2, 0.4, 0.5, 1.0, 2.0, 3.0, 4.0, 5.1, 10.6, 15.7, 20.7 and 26.3 mg/mL). Images were acquired using a novel 64-detector row SDCT system at 120 and 140 kVp. Acquisitions were repeated five times to assess reproducibility. Regions of interest (ROIs) were drawn on three slices per insert. A spectral plot was extracted for every ROI and mean attenuation profiles were fitted to known attenuation profiles of water and pure gadolinium using in-house-developed software to calculate gadolinium concentrations. At both 120 and 140 kVp, excellent correlations between scan repetitions and true and measured gadolinium concentrations were found (R > 0.99, P < 0.001; ICCs > 0.99, CI 0.99-1.00). Relative mean measurement errors stayed below 10% down to 2.0 mg/mL true gadolinium concentration at 120 kVp and below 5% down to 1.0 mg/mL true gadolinium concentration at 140 kVp. SDCT allows for accurate quantification of gadolinium at both 120 and 140 kVp. Lowest measurement errors were found for 140 kVp acquisitions. (orig.)

  20. Criticality experiments with low enriched UO2 fuel rods in water containing dissolved gadolinium

    International Nuclear Information System (INIS)

    Bierman, S.R.; Murphy, E.S.; Clayton, E.D.; Keay, R.T.

    1984-02-01

    The results obtained in a criticality experiments program performed for British Nuclear Fuels, Ltd. (BNFL) under contract with the United States Department of Energy (USDOE) are presented in this report along with a complete description of the experiments. The experiments involved low enriched UO 2 and PuO 2 -UO 2 fuel rods in water containing dissolved gadolinium, and are in direct support of BNFL plans to use soluble compounds of the neutron poison gadolinium as a primary criticality safeguard in the reprocessing of low enriched nuclear fuels. The experiments were designed primarily to provide data for validating a calculation method being developed for BNFL design and safety assessments, and to obtain data for the use of gadolinium as a neutron poison in nuclear chemical plant operations - particularly fuel dissolution. The experiments program covers a wide range of neutron moderation (near optimum to very under-moderated) and a wide range of gadolinium concentration (zero to about 2.5 g Gd/l). The measurements provide critical and subcritical k/sub eff/ data (1 greater than or equal to k/sub eff/ greater than or equal to 0.87) on fuel-water assemblies of UO 2 rods at two enrichments (2.35 wt % and 4.31 wt % 235 U) and on mixed fuel-water assemblies of UO 2 and PuO 2 -UO 2 rods containing 4.31 wt % 235 U and 2 wt % PuO 2 in natural UO 2 respectively. Critical size of the lattices was determined with water containing no gadolinium and with water containing dissolved gadolinium nitrate. Pulsed neutron source measurements were performed to determine subcritical k/sub eff/ values as additional amounts of gadolinium were successively dissolved in the water of each critical assembly. Fission rate measurements in 235 U using solid state track recorders were made in each of the three unpoisoned critical assemblies, and in the near-optimum moderated and the close-packed poisoned assemblies of this fuel

  1. Breath-hold gadolinium-enhanced MRA : clinical application

    International Nuclear Information System (INIS)

    Kang, Sung Gwon; Kang, Ji Hee; Kim, Won Hong; Lim, Myung Kwan; Cho, Young Kook; Cho, Soon Gu; Suh, Chang Hae

    1998-01-01

    The purpose of this study is to compare breath-hold gadolinium enhanced MR angiography (MRA) with digital subtraction angiography. Ten patients underwent angiography and breath-hold gadolinium enhanced MRA; the latter performed at 1.5T with 3D FSPGR after a bolus injection of gadopentetate dimeglumine (0.4m mol/kg). Seven of ten pathologic conditions (70%) evaluated by both techniques had a similar appearance. The conditions examined were as follows: the artery feeding renal cell carcinoma(n=2); renal artery stenosis (n=2); pulmonary AVM(n=2); abdominal aortic aneurysm (n=1); atheromatous plaque in the lower abdominal aorta (n=1); an enlarged bronchial artery (n=1); and an aberrant renal artery (n=1). For evaluating an anatomic relationship, a reconstructed 3D image obtained by MRA is more advantageous. Breath hold contrast enhanced MRA is a potentially useful noninvasive screening method for detecting vascular abnormality of the aorta and its branches. (author). 13 refs., 1 tab., 4 figs

  2. Breath-hold gadolinium-enhanced MRA : clinical application

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Sung Gwon; Kang, Ji Hee; Kim, Won Hong; Lim, Myung Kwan; Cho, Young Kook; Cho, Soon Gu; Suh, Chang Hae [Inha University Hospital, Inchon (Korea, Republic of)

    1998-05-01

    The purpose of this study is to compare breath-hold gadolinium enhanced MR angiography (MRA) with digital subtraction angiography. Ten patients underwent angiography and breath-hold gadolinium enhanced MRA; the latter performed at 1.5T with 3D FSPGR after a bolus injection of gadopentetate dimeglumine (0.4m mol/kg). Seven of ten pathologic conditions (70%) evaluated by both techniques had a similar appearance. The conditions examined were as follows: the artery feeding renal cell carcinoma(n=2); renal artery stenosis (n=2); pulmonary AVM(n=2); abdominal aortic aneurysm (n=1); atheromatous plaque in the lower abdominal aorta (n=1); an enlarged bronchial artery (n=1); and an aberrant renal artery (n=1). For evaluating an anatomic relationship, a reconstructed 3D image obtained by MRA is more advantageous. Breath hold contrast enhanced MRA is a potentially useful noninvasive screening method for detecting vascular abnormality of the aorta and its branches. (author). 13 refs., 1 tab., 4 figs.

  3. Gadolinium-enhanced magnetic resonance angiography in neonates and infants suspected of caval or aortic thrombosis

    International Nuclear Information System (INIS)

    Greenberg, S. Bruce; Bhutta, Sadaf T.; Buchmann, Robert F.

    2004-01-01

    Gadolinium-enhanced magnetic resonance angiography (MRA)is a well-established technique in older children and adults. No studies have focused on its use in neonates and small infants. Our objective was to study the use of gadolinium-enhanced MRA in neonates and infants suspected of caval or aortic thrombosis. Materials and Methods:Gadolinium-enhanced MR angiography was performed on seven neonates and small infants for the evaluation of caval or aortic thrombosis. Gadolinium-DTPA at a dose of 0.3 mmol/kg (minimum dose 1 ml) was injected using a power injector (0.2 ml/s). Contrast-enhanced MRA was performed using a 3-D, fast, radiofrequency spoiled gradient-echo sequence (TR/TE: 4.8/1.1, flip angle 45 , matrix 256 x 128, slice thickness 2.6 mm interpolated to 1.3 mm, FOV variable, NEX=1.0). Diagnostic-quality angiograms were obtained in all seven neonates. Superior vena cava thrombosis was identified in two neonates, and abdominal aortic thrombosis was present in one neonate. It is practical to perform gadolinium-enhanced MRA in neonates weighing as little as 600 g for the detection of caval or aortic thrombosis. (orig.)

  4. Gadolinium-enhanced magnetic resonance angiography in neonates and infants suspected of caval or aortic thrombosis

    Energy Technology Data Exchange (ETDEWEB)

    Greenberg, S. Bruce; Bhutta, Sadaf T.; Buchmann, Robert F. [University of Arkansas for Medical Sciences, Arkansas Children' s Hospital, Little Rock, AR (United States)

    2004-12-01

    Gadolinium-enhanced magnetic resonance angiography (MRA)is a well-established technique in older children and adults. No studies have focused on its use in neonates and small infants. Our objective was to study the use of gadolinium-enhanced MRA in neonates and infants suspected of caval or aortic thrombosis. Materials and Methods:Gadolinium-enhanced MR angiography was performed on seven neonates and small infants for the evaluation of caval or aortic thrombosis. Gadolinium-DTPA at a dose of 0.3 mmol/kg (minimum dose 1 ml) was injected using a power injector (0.2 ml/s). Contrast-enhanced MRA was performed using a 3-D, fast, radiofrequency spoiled gradient-echo sequence (TR/TE: 4.8/1.1, flip angle 45 , matrix 256 x 128, slice thickness 2.6 mm interpolated to 1.3 mm, FOV variable, NEX=1.0). Diagnostic-quality angiograms were obtained in all seven neonates. Superior vena cava thrombosis was identified in two neonates, and abdominal aortic thrombosis was present in one neonate. It is practical to perform gadolinium-enhanced MRA in neonates weighing as little as 600 g for the detection of caval or aortic thrombosis. (orig.)

  5. Giant cisterna chyli: MRI depiction with gadolinium-DTPA enhancement

    International Nuclear Information System (INIS)

    Lee, K.C.Y.; Cassar-Pullicino, V.N.

    2000-01-01

    AIM: To demonstrate the use of MRI with Gadolinium-DTPA enhancement in the diagnosis of giant cisterna chyli. MATERIALS AND METHODS: The study consisted of contrast enhanced MRI with ultrasound and CT correlation in three patients with a giant cisterna chyli. An analysis of the morphology, location and post-contrast MR signal characteristics in relation to time was performed. RESULTS: Cisterna chyli has a characteristic lobulated morphology and location but the unenhanced MRI appearances are not specific. The post-Gadolinium-DTPA MRI appearances are critically dependent on the time elapsed after injection of contrast medium. Within the first 5 min, there is no enhancement at all, but by 10 min there is early layering of contrast medium evident, which by 30 min produces a clear fluid-fluid level. Delayed images at 4-5 h demonstrate a uniform enhancement of the cisternal contents producing a homogeneous intermediate signal. All of these features are best visualized on T1 fast saturation sequences. CONCLUSION: MRI with Gadolinium-DTPA enhancement is valuable in confirming the nature of the lymphatic ducts in the retroperitoneal space and helps to differentiate these normal structures from alternative lesions such as lymphadenopathy and tumour recurrence. Lee, K.C.Y., Cassar-Pullicino, V.N. (2000)

  6. Feasibility of using gadolinium as a burnable poison in PWR cores. Final report

    International Nuclear Information System (INIS)

    Rothleder, B.M.

    1981-02-01

    As an alternative to the use of lumped burnable absorbers in PWR cores, distributed burnable absorbers are being considered for generic application. These burnable absorbers take the form of Gd 2 O 3 mixed with UO 2 in selected fuel rods (as is currently done in BWR cores). The work discussed herein concerns a three-dimensional feasibility study of the use of such distributed burnable absorbers in PWR cores. This study of distributed burnable absorbers was performed for the first cycle of a typical current design PWR using the following steps: analysis of a generic reference core design; determination of gadolinium assembly designs; determination of a generic gadolinium core design; evaluation of feasibility by examining selected parameters; and redesign of the generic gadolinium core, using axial zoning

  7. Correlation between gadolinium-diethylenetriaminepentaacetic acid contrast enhancement and thallium-201 chloride uptake in pediatric brainstem glioma.

    Science.gov (United States)

    Maria, B L; Drane, W B; Quisling, R J; Hoang, K B

    1997-09-01

    We previously showed that thallium-201 (201Tl) chloride is accumulated in over 75% of brain tumors, including brainstem gliomas. The imaging of 201Tl with single photon emission computed tomography (SPECT) may require an abnormal increase in permeability of tumor vessels to allow penetration of the blood-brain barrier. To test this hypothesis, we evaluated the correlation between gadolinium enhancement and the degree of 201Tl uptake on SPECT and the contributions of either gadolinium enhancement or 201Tl uptake to the prognosis in children with brainstem gliomas. Forty-two sets of paired SPECT scans and magnetic resonance imaging (MRI) scans were obtained longitudinally in 13 cases. Altogether, 31 of 42 pairs (74%) of scans showed concordance between the presence of gadolinium enhancement and 201Tl uptake. There were no cases that demonstrated 201Tl uptake but lacked gadolinium enhancement. The results indicate that 201Tl SPECT is of value primarily when brainstem tumors have vessels that are demonstrably permeable to gadolinium, prior to or as a result of radiotherapy.

  8. Nickel-based gadolinium alloy for neutron adsorption application in ram packages

    International Nuclear Information System (INIS)

    Robino, C.; McConnell, P.; Mizia, R.

    2004-01-01

    This paper will outline the results of a metallurgical development program that is investigating the alloying of gadolinium into a nickel-chromium-molybdenum alloy matrix. Gadolinium has been chosen as the neutron absorption alloying element due to its high thermal neutron absorption cross section and low solubility in the expected U.S. repository environment. The nickel-chromium-molybdenum alloy family was chosen for its known corrosion performance, mechanical properties, and weldability. The workflow of this program includes chemical composition definition, primary and secondary melting studies, ingot conversion processes, properties testing, and national consensus codes and standards work. The microstructural investigation of these alloys shows that the gadolinium addition is not soluble in the primary austenite metallurgical phase and is present in the alloy as gadolinium-rich second phase. This is similar to what is observed in a stainless steel alloyed with boron. The mechanical strength values are similar to those expected for commercial Ni-Cr-Mo alloys. The alloys have been corrosion tested in simulated Yucca Mountain aqueous chemistries with acceptable results. The initial results of weldability tests have also been acceptable. Neutronic testing in a moderated critical array has generated favorable results. An American Society for Testing and Materials material specification has been issued for the alloy and a Code Case has been submitted to the American Society of Mechanical Engineers for code qualification. The ultimate goal is acceptance of the alloy for use at the Yucca Mountain repository

  9. Gadolinium Deposition in Human Brain Tissues after Contrast-enhanced MR Imaging in Adult Patients without Intracranial Abnormalities.

    Science.gov (United States)

    McDonald, Robert J; McDonald, Jennifer S; Kallmes, David F; Jentoft, Mark E; Paolini, Michael A; Murray, David L; Williamson, Eric E; Eckel, Laurence J

    2017-11-01

    Purpose To determine whether gadolinium deposits in neural tissues of patients with intracranial abnormalities following intravenous gadolinium-based contrast agent (GBCA) exposure might be related to blood-brain barrier integrity by studying adult patients with normal brain pathologic characteristics. Materials and Methods After obtaining antemortem consent and institutional review board approval, the authors compared postmortem neuronal tissue samples from five patients who had undergone four to 18 gadolinium-enhanced magnetic resonance (MR) examinations between 2005 and 2014 (contrast group) with samples from 10 gadolinium-naive patients who had undergone at least one MR examination during their lifetime (control group). All patients in the contrast group had received gadodiamide. Neuronal tissues from the dentate nuclei, pons, globus pallidus, and thalamus were harvested and analyzed with inductively coupled plasma mass spectrometry (ICP-MS), transmission electron microscopy with energy-dispersive x-ray spectroscopy, and light microscopy to quantify, localize, and assess the effects of gadolinium deposition. Results Tissues from the four neuroanatomic regions of gadodiamide-exposed patients contained 0.1-19.4 μg of gadolinium per gram of tissue in a statistically significant dose-dependent relationship (globus pallidus: ρ = 0.90, P = .04). In contradistinction, patients in the control group had undetectable levels of gadolinium with ICP-MS. All patients had normal brain pathologic characteristics at autopsy. Three patients in the contrast group had borderline renal function (estimated glomerular filtration rate the contrast group was localized to the capillary endothelium and neuronal interstitium and, in two cases, within the nucleus of the cell. Conclusion Gadolinium deposition in neural tissues after GBCA administration occurs in the absence of intracranial abnormalities that might affect the permeability of the blood-brain barrier. These findings

  10. Gadolinium-enhanced MRI in central nervous system Behcet's disease

    Energy Technology Data Exchange (ETDEWEB)

    Erdem, E. (Dept. of Radiology (Neuroradiology), Hopital de Bicetre, Paris-Sud Univ. (France)); Carlier, R. (Dept. of Radiology (Neuroradiology), Hopital de Bicetre, Paris-Sud Univ. (France)); Idir, A.B.C. (Dept. of Radiology (Neuroradiology), Hopital de Bicetre, Paris-Sud Univ. (France)); Masnou, P.O. (Dept. of Neurology, Hopital de Bicetre, Paris-Sud Univ. (France)); Moulonguet, A. (Dept. of Neurology, Hopital de Bicetre, Paris-Sud Univ. (France)); Adams, D. (Dept. of Neurology, Hopital de Bicetre, Paris-Sud Univ. (France)); Doyon, D. (Dept. of Radiology (Neuroradiology), Hopital de Bicetre, Paris-Sud Univ. (France))

    1993-02-01

    Two cases of central nervous system Behcet's disease, studied by gadolinium-enhanced MRI, are presented. In one patient, whose clinical picture was dominated by a brain stem syndrome, the gadolinium enhancement resolved with clinical improvement, although the hyperintense areas in the mesencephalon on T2-weighted images persisted. In the second, who had a pseudobulbar palsy and a mild right hemiparesis, there were many abnormal areas, but an enhancing focus in the posterior limb of the left internal capsule was probably the lesion responsible for the hemiparesis. (orig.)

  11. Accurate late gadolinium enhancement prediction by early T1- based quantitative synthetic mapping

    Energy Technology Data Exchange (ETDEWEB)

    Dijk, Randy van; Harst, Pim van der [University of Groningen, University Medical Centre Groningen, Centre for Medical Imaging, Groningen (Netherlands); University of Groningen, University Medical Centre Groningen, Department of Cardiology, Groningen (Netherlands); Kuijpers, Dirkjan [University of Groningen, University Medical Centre Groningen, Centre for Medical Imaging, Groningen (Netherlands); Department of Cardiovascular Imaging HMC-Bronovo, The Hague (Netherlands); Kaandorp, Theodorus A.M.; Dijkman, Paul R.M. van [Department of Cardiovascular Imaging HMC-Bronovo, The Hague (Netherlands); Vliegenthart, Rozemarijn [University of Groningen, University Medical Center Groningen, Department of Radiology, Groningen (Netherlands); Oudkerk, Matthijs [University of Groningen, University Medical Centre Groningen, Centre for Medical Imaging, Groningen (Netherlands); University Medical Center Groningen, Center for Medical Imaging, Groningen (Netherlands)

    2018-02-15

    Early synthetic gadolinium enhancement (ESGE) imaging from post-contrast T1 mapping after adenosine stress-perfusion cardiac magnetic resonance (CMR) was compared to conventional late gadolinium enhancement (LGE) imaging for assessing myocardial scar. Two hundred fourteen consecutive patients suspected of myocardial ischaemia were referred for stress-perfusion CMR. Myocardial infarct volume was quantified on a per-subsegment basis in both synthetic (2-3 min post-gadolinium) and conventional (9 min post-gadolinium) images by two independent observers. Sensitivity, specificity, PPV and NPV were calculated on a per-patient and per-subsegment basis. Both techniques detected 39 gadolinium enhancement areas in 23 patients. The median amount of scar was 2.0 (1.0-3.1) g in ESGE imaging and 2.2 (1.1-3.1) g in LGE imaging (p=0.39). Excellent correlation (r=0.997) and agreement (mean absolute difference: -0.028±0.289 ml) were found between ESGE and LGE images. Sensitivity, specificity, PPV and NPV of ESGE imaging were 96 (78.9-99.9), 99 (97.1-100.0)%, 96 (76.5-99.4) and 99.5 (96.6-99.9) in patient-based and 99 (94.5-100.0), 100 (99.9-100.0)%, 97.0 (91.3-99.0) and 100.0 (99.8-100.0) in subsegment-based analysis. ESGE based on post-contrast T1 mapping after adenosine stress-perfusion CMR imaging shows excellent agreement with conventional LGE imaging for assessing myocardial scar, and can substantially shorten clinical acquisition time. (orig.)

  12. Accurate late gadolinium enhancement prediction by early T1- based quantitative synthetic mapping

    International Nuclear Information System (INIS)

    Dijk, Randy van; Harst, Pim van der; Kuijpers, Dirkjan; Kaandorp, Theodorus A.M.; Dijkman, Paul R.M. van; Vliegenthart, Rozemarijn; Oudkerk, Matthijs

    2018-01-01

    Early synthetic gadolinium enhancement (ESGE) imaging from post-contrast T1 mapping after adenosine stress-perfusion cardiac magnetic resonance (CMR) was compared to conventional late gadolinium enhancement (LGE) imaging for assessing myocardial scar. Two hundred fourteen consecutive patients suspected of myocardial ischaemia were referred for stress-perfusion CMR. Myocardial infarct volume was quantified on a per-subsegment basis in both synthetic (2-3 min post-gadolinium) and conventional (9 min post-gadolinium) images by two independent observers. Sensitivity, specificity, PPV and NPV were calculated on a per-patient and per-subsegment basis. Both techniques detected 39 gadolinium enhancement areas in 23 patients. The median amount of scar was 2.0 (1.0-3.1) g in ESGE imaging and 2.2 (1.1-3.1) g in LGE imaging (p=0.39). Excellent correlation (r=0.997) and agreement (mean absolute difference: -0.028±0.289 ml) were found between ESGE and LGE images. Sensitivity, specificity, PPV and NPV of ESGE imaging were 96 (78.9-99.9), 99 (97.1-100.0)%, 96 (76.5-99.4) and 99.5 (96.6-99.9) in patient-based and 99 (94.5-100.0), 100 (99.9-100.0)%, 97.0 (91.3-99.0) and 100.0 (99.8-100.0) in subsegment-based analysis. ESGE based on post-contrast T1 mapping after adenosine stress-perfusion CMR imaging shows excellent agreement with conventional LGE imaging for assessing myocardial scar, and can substantially shorten clinical acquisition time. (orig.)

  13. Efficacy of gadolinium enhanced MR imaging for the diagnosis of Legg-Calve-Perthes disease

    International Nuclear Information System (INIS)

    Kim, Jee Eun; Kim, Hyung Sik; Kim, Ji Hye

    2008-01-01

    The purpose of this study was to evaluate the efficacy of gadolinium enhanced MR imaging for making the diagnosis of Legg-Calve-Perthes (LCP) disease. We studied the gadolinium enhanced MR images of 14 hips in 12 children who had the diagnosis of LCP disease. We retrospectively analyzed the extent of necrosis, the epiphyseal revascularization pathways and the metaphyseal changes. The absence of enhancement on gadolinium enhanced MRI was noted in all cases of LCP disease. Diffuse absence of enhancement was observed in 9 femoral epiphyses. Two of them showed normal bone marrow signal intensity on the T1 and T1-weighted images. Focal absence of enhancement was observed in 5 femoral epiphyses. Enhanced MRI showed better epiphyseal revascularization in the lateral column (five cases), in the lateral and medial columns (four cases) and in the transphyseal pathway (three cases). Metaphyseal change was observed in two cases. Gadolinium enhanced MRI allows detection of LCP disease and an accurate analysis of the different revascularization patterns, and this helpful for predicting the prognosis

  14. Myocardial late gadolinium enhancement in specific cardiomyopathies by cardiovascular magnetic resonance: a preliminary experience.

    Science.gov (United States)

    Silva, Caterina; Moon, James C; Elkington, Andrew G; John, Anna S; Mohiaddin, Raad H; Pennell, Dudley J

    2007-12-01

    Late gadolinium enhancement cardiovascular magnetic resonance (CMR) can visualize myocardial interstitial abnormalities. The aim of this study was to assess whether regions of abnormal myocardium can also be visualized by late enhancement gadolinium CMR in the specific cardiomyopathies. A retrospective review of all referrals for gadolinium CMR with specific cardiomyopathy over 20 months. Nine patients with different specific cardiomyopathies were identified. Late enhancement was demonstrated in all patients, with a mean signal intensity of 390 +/- 220% compared with normal regions. The distribution pattern of late enhancement was unlike the subendocardial late enhancement related to coronary territories found in myocardial infarction. The affected areas included papillary muscles (sarcoid), the mid-myocardium (Anderson-Fabry disease, glycogen storage disease, myocarditis, Becker muscular dystrophy) and the global sub-endocardium (systemic sclerosis, Loeffler's endocarditis, amyloid, Churg-Strauss). Focal myocardial late gadolinium enhancement is found in the specific cardiomyopathies, and the pattern is distinct from that seen in infarction. Further systematic studies are warranted to assess whether the pattern and extent of late enhancement may aid diagnosis and prognostic assessment.

  15. Biodistribution of ultra small gadolinium-based nanoparticles as theranostic agent: application to brain tumors.

    Science.gov (United States)

    Miladi, Imen; Duc, Géraldine Le; Kryza, David; Berniard, Aurélie; Mowat, Pierre; Roux, Stéphane; Taleb, Jacqueline; Bonazza, Pauline; Perriat, Pascal; Lux, François; Tillement, Olivier; Billotey, Claire; Janier, Marc

    2013-09-01

    Gadolinium-based nanoparticles are novel objects with interesting physical properties, allowing their use for diagnostic and therapeutic applications. Gadolinium-based nanoparticles were imaged following intravenous injection in healthy rats and rats grafted with 9L gliosarcoma tumors using magnetic resonance imaging and scintigraphic imaging. Quantitative biodistribution using gamma-counting of each sampled organ confirmed that these nanoparticles were rapidly cleared essentially by renal excretion. Accumulation of these nanoparticles in 9L gliosarcoma tumors implanted in the rat brain was quantitated. This passive and long-duration accumulation of gadolinium-based nanoparticles in tumor, which is related to disruption of the blood-brain barrier, is in good agreement with the use of these nanoparticles as radiosensitizers for brain tumors.

  16. Pediatric Patients Demonstrate Progressive T1-Weighted Hyperintensity in the Dentate Nucleus following Multiple Doses of Gadolinium-Based Contrast Agent.

    Science.gov (United States)

    Roberts, D R; Chatterjee, A R; Yazdani, M; Marebwa, B; Brown, T; Collins, H; Bolles, G; Jenrette, J M; Nietert, P J; Zhu, X

    2016-12-01

    While there have been recent reports of brain retention of gadolinium following gadolinium-based contrast agent administration in adults, a retrospective series of pediatric patients has not previously been reported, to our knowledge. We investigated the relationship between the number of prior gadolinium-based contrast agent doses and increasing T1 signal in the dentate nucleus on unenhanced T1-weighted MR imaging. We hypothesized that despite differences in pediatric physiology and the smaller gadolinium-based contrast agent doses that pediatric patients are typically administered based on weighted-adjusted dosing, the pediatric brain would also demonstrate dose-dependent increasing T1 signal in the dentate nucleus. We included children with multiple gadolinium-based contrast agent administrations at our institution. A blinded reader placed ROIs within the dentate nucleus and adjacent cerebellar white matter. To eliminate reader bias, we also performed automated ROI delineation of the dentate nucleus, cerebellar white matter, and pons. Dentate-to-cerebellar white matter and dentate-to pons ratios were compared with the number of gadolinium-based contrast agent administrations. During 20 years at our institution, 280 patients received at least 5 gadolinium-based contrast agent doses, with 1 patient receiving 38 doses. Sixteen patients met the inclusion/exclusion criteria for ROI analysis. Blinded reader dentate-to-cerebellar white matter ratios were significantly associated with gadolinium-based contrast agent doses (r s = 0.77, P = .001). The dentate-to-pons ratio and dentate-to-cerebellar white matter ratios based on automated ROI placement were also significantly correlated with gadolinium-based contrast agent doses (t = 4.98, P contrast agent doses is significantly correlated with progressive T1-weighted dentate hyperintensity. Definitive confirmation of gadolinium deposition requires tissue analysis. Any potential clinical sequelae of gadolinium retention in

  17. In vitro radiosensitizing effects of ultrasmall gadolinium based particles on tumour cells.

    Science.gov (United States)

    Mowat, P; Mignot, A; Rima, W; Lux, F; Tillement, O; Roulin, C; Dutreix, M; Bechet, D; Huger, S; Humbert, L; Barberi-Heyob, M; Aloy, M T; Armandy, E; Rodriguez-Lafrasse, C; Le Duc, G; Roux, S; Perriat, P

    2011-09-01

    Since radiotherapy is widely used in cancer treatment, it is essential to develop strategies which lower the irradiation burden while increasing efficacy and become efficient even in radio resistant tumors. Our new strategy is relying on the development of solid hybrid nanoparticles based on rare-earth such as gadolinium. In this paper, we then evidenced that gadolinium-based particles can be designed to enter efficiently into the human glioblastoma cell line U87 in quantities that can be tuned by modifying the incubation conditions. These sub-5 nm particles consist in a core of gadolinium oxide, a shell of polysiloxane and are functionalized by diethylenetriaminepentaacetic acid (DTPA). Although photoelectric effect is maximal in the [10-100 keV] range, such particles were found to possess efficient in-vitro radiosensitizing properties at an energy of 660 keV by using the "single-cell gel electrophoresis comet assay," an assay that measures the number of DNA damage that occurs during irradiation. Even more interesting, the particles have been evidenced by MTT assays to be also efficient radiosensitizers at an energy of 6 MeV for doses comprised between 2 and 8 Gy. The properties of the gadolinium-based particles give promising opening to a particle-assisted radio-therapy by using irradiation systems already installed in the majority of hospitals.

  18. Fumonisin B1 hepatotoxicity in mice is attenuated by depletion of Kupffer cells by gadolinium chloride

    International Nuclear Information System (INIS)

    He, Quanren; Kim, Jiyoung; Sharma, Raghubir P.

    2005-01-01

    Fumonisin B 1 (FB 1 ) is a toxic and carcinogenic mycotoxin produced by Fusarium verticillioides found on corn worldwide. The biological effects of FB 1 are attributed to sphingolipid metabolism disruption as a result of ceramide synthase inhibition. Tumor necrosis factor α (TNFα) is an important modulator of FB 1 hepatotoxicity. Kupffer cells are major source of cytokine production in liver. In the present study we investigated the effects of Kupffer cell depletion by gadolinium on FB 1 hepatotoxicity in female BALB/c mice. Mice were given saline or 50 mg/kg of gadolinium chloride once via the tail vein; 16 h later they were treated with subcutaneous injections of vehicle or 2.25 mg/kg/day FB 1 in saline for three successive days. Gadolinium significantly attenuated FB 1 -induced increases in the activities of circulating alanine aminotransferase and aspartate aminotransferase and reduced the FB 1 -induced hepatocyte apoptosis and free sphinganine accumulation in liver. Both gadolinium and FB 1 treatments individually increased the expression of selected cell signal factors; e.g., TNFα, TNF receptor 1, TNF-related apoptosis-inducing ligand, lymphotoxin β, interferon γ, and transforming growth factor β1; gadolinium chloride did not alter FB 1 -induced expression of the above genes. Results indicated that Kupffer cells play a role in FB 1 hepatotoxicity. Decreased FB 1 -induced sphinganine accumulation and increased protective TNFα signaling by gadolinium chloride may in part account for its ameliorating effect on FB 1 liver damage

  19. Fat-suppressed MRI of musculoskeletal infection: fast T2-weighted techniques versus gadolinium-enhanced T1-weighted images

    International Nuclear Information System (INIS)

    Miller, T.T.; Randolph, D.A. Jr.; Staron, R.B.; Feldman, F.; Cushin, S.

    1997-01-01

    Purpose. To investigate gadolinium's role in imaging musculoskeletal infection by comparing the conspicuity and extent of inflammatory changes demonstrated on gadolinium-enhanced fat-suppressed T1-weighted images versus fat-suppressed fast T2-weighted sequences. Design. Eighteen patients with infection were imaged in a 1.5-T unit, using frequency-selective and/or inversion recovery fat-suppressed fast T2-weighted images (T2WI) and gadolinium-enhanced frequency-selective fat-suppressed T1-weighted images (T1WI). Thirty-four imaging planes with both a fat-suppressed gadolinium-enhanced T1-weighted sequence and a fat-suppressed T2-weighted sequence were obtained. Comparison of the extent and conspicuity of signal intensity changes was made for both bone and soft tissue in each plane. Results. In bone, inflammatory change was equal in extent and conspicuity on fat-suppressed T2WI and fat-suppressed T1WI with gadolinium in 19 planes, more extensive or conspicuous on T2WI in three planes, and less so on T2WI in two planes. Marrow was normal on all three sequences in 10 cases. In soft tissue, inflammatory change was seen equally well in 20 instances, more extensively or conspicuously on the T2WI in 11 instances, and less so on T2WI in 2 instances. One case had no soft tissue involvement on any of the sequences. Five abscesses and three joint effusions were present, all more conspicuously delineated from surrounding inflammatory change on the fat-saturated T1WI with gadolinium. The average imaging time for the fat-saturated T1WI with gadolinium was 6.75 min, while that of the T2-weighted sequences was 5.75 min. Conclusion. Routine use of gadolinium is not warranted. Instead, gadolinium should be reserved for clinically suspected infection in or around a joint, and in cases refractory to medical or surgical treatment due to possible abscess formation. (orig.)

  20. Growth, characterization and dielectric studies of gadolinium ...

    Indian Academy of Sciences (India)

    nitrogen atmosphere leads to the formation of gadolinium oxide as the final product. ... from Chengdu Haoxuan Technology Co. Ltd, China ..... by metal cations. A band centered at 1534.78 cm. −1 is due to asymmetric stretching of coordinated carboxylate group vas(COO. −. ). Another absorption band at 1398.38 cm. −1 is.

  1. Electrochemical characterization of calcium cobaltite based porous electrodes; Caracterizacao eletroquimica de eletrodos porosos a base de cobaltita de calcio

    Energy Technology Data Exchange (ETDEWEB)

    Fulgencio, E.B.G.A.; Vasconcelos, K.; Silva, R.M.; Melo, P.; Caetano, A.A.; Campos, L.F.A.; Dutra, R.P.S.; Macedo, D.A., E-mail: erikbgrisi@gmail.com [Universidade Federal da Paraiba (UFPB), PB (Brazil)

    2016-07-01

    Materials based on alkali metal oxides and alkaline earth metal have shown high technological interest in recent years. Among these materials, calcium and cobalt oxide composition Ca{sub 3}Co{sub 4}O{sub 9} (C349) has emerged as thermoelectric material and, more recently, as cathode for solid oxide fuel cell (SOFC). In this study, C349 powder was obtained by solid state reaction of a mixture containing cobalt oxide and calcium carbonate from shellfish shells (CaCO{sub 3} ∼ 98%), previously calcined at 550° C. Symmetrical cells (cathode / substrate / cathode) were prepared by screen printing of C349 electrodes in gadolinium-doped ceria substrates. The characterization by electrochemical impedance spectroscopy revealed that the C349 obtained in this work has an area specific resistance compatible with electrodes obtained by chemical routes (from literature). (author)

  2. Gadolinium-DTPA and gadodiamide as an alternative contrast medium for CT

    International Nuclear Information System (INIS)

    Engelbrecht, V.; Koch, J.A.; Rassek, M.; Moedder, U.

    1996-01-01

    To evaluate the effect of intravenously applied gadolinium-based contrast medium in computed tomographic (CT) studies. Serial dilutions of iohexol 300, Gd-DTPA and gadodiamide were scanned with CT in a phantom study using water filled tubes. For quantification of X-ray attenuation, the mean Hounsfield units (HU) were calculated from the CT scans. Five patients with contraindications against iodine contrast agents were examined with abdominal or thoracic CT before and after application of 0.2 mmol/kg body weight of a gadolinium-based contrast agent. In these patients attenuation values were obtained in ROI from unenhanced and enhanced CT scans. The phantom study revealed a 38,4% enhancement for Gd-DTPA and a 35.7% enhancement for gadodiamide scaled on the reference measurements with iohexol 300. Thus, 130.2 ml Gd-DTPA or 140.1 ml gadodiamide are needed to achieve the same attenuation as an i.v. injection of 50 ml iohexol 300. Consequently the corresponding dose of 1 mmol/kg body weight would exceed the manufacturer's recommended dose. In four patients with complete thoracic or abdominal CT, i.v. applied gadolinium-based contrast medium (0.2 mmol/kg) yielded no visible advantage. In these patients parenchymal enhancement did not exceed 25%. Dynamic CT of a patient with focal liver lesion revealed an arterial enhancement peak of 75%. Sufficient parenchymal enhancement in CT studies cannot be achieved with the available gadolinium-based contrast mediums. They might be helpful if only short time vascular enhancement is required. (orig.) [de

  3. Gadolinium-hydrogen ion exchange of zirconium phosphate

    Science.gov (United States)

    Liu, D. C.; Power, J. L.

    1972-01-01

    The Gd(+3)/H(+) ion exchange on a commercial zirconium phosphate ion exchanger was investigated in chloride, sulfate, and phosphate solutions of Gd(+3) at gadolinium concentrations of 0.001 to 1 millimole per cc and in the pH range of 0 to 3.5. Relatively low Gd(+3) capacities, in the range of 0.01 to 0.1 millimole per g of ion exchanger were found at room temperature. A significant difference in Gd(+3) sorption was observed, depending on whether the ion exchanger was converted from initial conditions of greater or lesser Gd(+3) sorption than the specific final conditions. Correlations were found between decrease in Gd(+3) capacity and loss of exchanger phosphate groups due to hydrolysis during washing and between increase in capacity and treatment with H3PO4. Fitting of the experimental data to ideal ion exchange equilibrium expressions indicated that each Gd(+3) ion is sorbed on only one site of the ion exchanger. The selectivity quotient was determined to be 2.5 + or - 0.4 at room temperature on gadolinium desorption in chloride solutions.

  4. Laser spectroscopy and laser isotope separation of atomic gadolinium

    International Nuclear Information System (INIS)

    Chen, Y. W.; Yamanaka, C.; Nomaru, K.; Kou, K.; Niki, H.; Izawa, Y.; Nakai, S.

    1994-01-01

    Atomic vapor laser isotope separation (AVLIS) is a process which uses intense pulsed lasers to selectively photoionize one isotopic species of a chemical element, after which these ions are extracted electromagnetically. The AVLIS has several advantages over the traditional methods based on the mass difference, such as high selectivity, low energy consumption, short starting time and versatility to any atoms. The efforts for atomic vapor laser isotope separation at ILT and ILE, Osaka University have been concentrated into the following items: 1) studies on laser spectroscopy and laser isotope separation of atomic gadolinium, 2) studies on interaction processes including coherent dynamics, propagation effects and atom-ion collision in AVLIS system, 3) development of laser systems for AVLIS. In this paper, we present experimental results on the laser spectroscopy and laser isotope separation of atomic gadolinium.

  5. MRI with gadolinium DTPA in the diagnosis of spinal intradural masses

    International Nuclear Information System (INIS)

    Kahn, T.; Fuerst, G.; Moedder, U.; Roosen, N.; Lins, E.; Bock, W.J.; Lenard, H.G.

    1989-01-01

    The results of contrast enhanced MRI in 36 patients with suspected spinal intradural tumours are described. All intramedullary tumours showed distinctive enhancement and solid tumors could be delineated clearly, even if they were not clearly visible on unenhanced scans. The differentiation between neoplasm and non-neoplastic syrinx was markedly improved. The sensitivity of MRI for demonstrating intradural extramedullary tumours was greatly improved by gadolinium DTPA and even small lesions or flat meningeal infiltrates could be visualised. In addition, gadolinium DTPA improved the delineation and localisation of larger lesions, even if they had already been seen on unenhanced images. (orig.) [de

  6. Radio response of human lymphocytes pretreated with boron and gadoliniums assessed by the, comet assay

    International Nuclear Information System (INIS)

    Kim, J. K.; Park, T. W.; Cebulska-Wasiewska, A.; Nili, M.

    2009-01-01

    Boron and gadolinium are among the nuclides that hold a unique property of being a neutron capture therapy agent. Neutron beams have often a considerable portion of gamma rays with fast neutrons. Gamma rays, as beam contaminants, can cause considerable damage to normal tissues even if such tissues do contain high boron concentrations. Materials and Methods: The modification of radio response in human lymphocytes pretreated with boron or gadolinium compound was studied by assessing the DNA damage using single cell gel electrophoresis, the comet assay. The lymphocytes from the human peripheral blood were irradiated with 0, 1, 2 and 4 Gy of gamma rays from a 60 Co isotopic source with or without pretreatment of boron or gadolinium compound for 10 minutes at 4 d egree C . Post-irradiation procedures included slide preparation, cell-lysing, unwinding and electrophoresis, neutralization, staining, and analytic steps, gel electrophoresis. Results: The results indicate that pretreatment with boron compound (50 n M or 250 n M of 10 B) is effective in reducing the radiosensitivity of the lymphocyte DNA. Conversely, pretreatment with gadolinium compound (50 n M) led to a dose-dependent increase in the radiosensitivity, most prominently with a dose of 4 Gy (P<0.001). Furthermore, when the lymphocytes were pretreated with a Combined mixture (1:1) of boron (250 n M) and gadolinium (50 n M) compounds, the reduced radiosensitivity was also observed.

  7. Comparison of digital subtraction angiography with gadolinium-enhanced magnetic resonance angiography in the diagnosis of renal artery stenosis

    International Nuclear Information System (INIS)

    Thornton, J.; O'Callaghan, J.; Varghese, J.C.; Lee, M.J.; Walshe, J.; O'Brien, E.

    1999-01-01

    Renal artery stenosis (RAS) is a treatable cause of hypertension and renal failure for which no ideal screening technique is currently available. We evaluated the use of dynamic gadolinium-enhanced magnetic resonance angiography (MRA) for the diagnosis of RAS. Sixty-two patients with secondary hypertension were enrolled in the study. All patients had conventional renal angiography and gadolinium enhanced MRA. The sequence used was a 3D FMP SPGR sequence with the following parameters (TR: 26 ms, TE: 6.9 ms, flip angle 40 , field of view 36 x 36 cm, matrix 246 x 256, 1 excitation). Gadolinium 0.3 mmol/kg was administered and 60 1.5-mm-thick partitions were obtained over a duration of 3.5 min. The MRA images were then compared with conventional digital subtraction angiography (DSA) images. Conventional DSA demonstrated 138 renal arteries, whereas gadolinium-enhanced MRA demonstrated 129 (93 %). Twenty-one renal artery stenoses and four occluded arteries were seen at conventional DSA. Gadolinium-enhanced MRA had a sensitivity of 88 %, specificity of 98 %, accuracy of 96 %, positive predictive value of 92 % and negative predictive value of 97 % when compared with conventional DSA. Gadolinium-enhanced MRA is an accurate technique for identifying patients with RAS. It is less sensitive in picking up accessory renal arteries. (orig.)

  8. Complications from the use of intravenous gadolinium-based contrast agents for magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Elias Junior, Jorge; Santos, Antonio Carlos dos; Nogueira-Barbosa, Marcello Henrique; Muglia, Valdair Francisco; Koenigkam-Santos, Marcel [Universidade de Sao Paulo (USP), Ribeirao Preto, SP (Brazil). Hospital das Clinicas. Centro de Ciencias das Imagens e Fisica Medica]. E-mail: jejunior@fmrp.usp.br

    2008-07-15

    Gadolinium-based contrast agents are much safer than the iodinated ones; however complications may occur and should be recognized for appropriate orientation and management. The total incidence of adverse reactions to contrast agents in magnetic resonance imaging ranges between 2% and 4%. Cases of severe acute reactions to gadolinium, such as laryngospasm and anaphylactic shock, are rare. Chronic complications secondary to the use of gadolinium also can occur and, recently an association between its use and a rare dermatologic disease occurring in patients with renal failure has been reported. Nephrogenic systemic fibrosis was the subject of an official health notification issued by the American Food and Drug Administration. This progressive disease is characterized by hardened skin with fibrotic nodules and plaques which may involve other parts of the body. Patients who have been affected by this disorder presented chronic renal failure, with metabolic acidosis and had been submitted to magnetic resonance angiography, probably involving exposure to large amounts of intravenous paramagnetic contrast. This review is aimed at presenting a succinct description of the gadolinium-based contrast agent types, possible secondary complications, their preventive measures and management. (author)

  9. Can unenhanced multiparametric MRI substitute gadolinium-enhanced MRI in the characterization of vertebral marrow infiltrative lesions?

    Directory of Open Access Journals (Sweden)

    Dalia Z. Zidan

    2014-06-01

    Conclusion: Unenhanced-multiparametric MRI is compatible with gadolinium-enhanced MRI in reliable characterization of marrow infiltrative lesions. The routine MRI protocol of cancer patients should be altered to accommodate the evolving MRI technology and cost effectively substitute the need for a gadolinium enhanced scan.

  10. Diffusion properties of conventional and calcium-sensitive MRI contrast agents in the rat cerebral cortex.

    Science.gov (United States)

    Hagberg, Gisela E; Mamedov, Ilgar; Power, Anthony; Beyerlein, Michael; Merkle, Hellmut; Kiselev, Valerij G; Dhingra, Kirti; Kubìček, Vojtĕch; Angelovski, Goran; Logothetis, Nikos K

    2014-01-01

    Calcium-sensitive MRI contrast agents can only yield quantitative results if the agent concentration in the tissue is known. The agent concentration could be determined by diffusion modeling, if relevant parameters were available. We have established an MRI-based method capable of determining diffusion properties of conventional and calcium-sensitive agents. Simulations and experiments demonstrate that the method is applicable both for conventional contrast agents with a fixed relaxivity value and for calcium-sensitive contrast agents. The full pharmacokinetic time-course of gadolinium concentration estimates was observed by MRI before, during and after intracerebral administration of the agent, and the effective diffusion coefficient D* was determined by voxel-wise fitting of the solution to the diffusion equation. The method yielded whole brain coverage with a high spatial and temporal sampling. The use of two types of MRI sequences for sampling of the diffusion time courses was investigated: Look-Locker-based quantitative T(1) mapping, and T(1) -weighted MRI. The observation times of the proposed MRI method is long (up to 20 h) and consequently the diffusion distances covered are also long (2-4 mm). Despite this difference, the D* values in vivo were in agreement with previous findings using optical measurement techniques, based on observation times of a few minutes. The effective diffusion coefficient determined for the calcium-sensitive contrast agents may be used to determine local tissue concentrations and to design infusion protocols that maintain the agent concentration at a steady state, thereby enabling quantitative sensing of the local calcium concentration. Copyright © 2014 John Wiley & Sons, Ltd.

  11. The critical thermal expansion of gadolinium

    International Nuclear Information System (INIS)

    Robinson, K.; Lanchester, P.C.

    1978-01-01

    Measurements have been made of the critical thermal expansion of single crystals of gadolinium, prepared by solid state electrotransport processing. Although the expansion data can be fitted to a simple power law with exponents lambda + =-0.25, lambda - =-0.33, these values are not predicted by theory and a discontinuity remains at Tsub(c)=293.620 K. It is suggested that the results relate to a region of crossover to uniaxial dipolar behaviour. (Auth.)

  12. A polymeric fastener can easily functionalize liposome surfaces with gadolinium for enhanced magnetic resonance imaging.

    Science.gov (United States)

    Smith, Cartney E; Shkumatov, Artem; Withers, Sarah G; Yang, Binxia; Glockner, James F; Misra, Sanjay; Roy, Edward J; Wong, Chun-Ho; Zimmerman, Steven C; Kong, Hyunjoon

    2013-11-26

    Common methods of loading magnetic resonance imaging (MRI) contrast agents into nanoparticles often suffer from challenges related to particle formation, complex chemical modification/purification steps, and reduced contrast efficiency. This study presents a simple, yet advanced process to address these issues by loading gadolinium, an MRI contrast agent, exclusively on a liposome surface using a polymeric fastener. The fastener, so named for its ability to physically link the two functional components together, consisted of chitosan substituted with diethylenetriaminepentaacetic acid (DTPA) to chelate gadolinium, as well as octadecyl chains to stabilize the modified chitosan on the liposome surface. The assembly strategy, mimicking the mechanisms by which viruses and proteins naturally anchor to a cell, provided greater T1 relaxivity than liposomes loaded with gadolinium in both the interior and outer leaflet. Gadolinium-coated liposomes were ultimately evaluated in vivo using murine ischemia models to highlight the diagnostic capability of the system. Taken together, this process decouples particle assembly and functionalization and, therefore, has considerable potential to enhance imaging quality while alleviating many of the difficulties associated with multifunctional particle fabrication.

  13. Nuclear orientation experiments on the magnetic moments of europium and gadolinium nuclei

    International Nuclear Information System (INIS)

    Berg, F.G. van den.

    1984-01-01

    In this thesis, experimental results on the ground state nuclear magnetic moments of europium and gadolinium isotopes are presented. The nuclear orientation experiments were performed on europium and gadolinium nuclei embedded in several host lattices. Attention is paid to the hyperfine interactions of the ions. Nuclear moments are discussed in the context of nuclear shell model. The theoretical framework is described for nuclear structure and low temperature nuclear orientation. Furthermore, the experimental techniques, the technical arrangement of the orientation apparatus, the methods for radiative detection and the use of nuclear orientation thermometry are described. (Auth.)

  14. Gadolinium retention after administration of contrast agents based on linear chelators and the recommendations of the European Medicines Agency

    International Nuclear Information System (INIS)

    Dekkers, Ilona A.; Roos, Rick; Molen, Aart J. van der

    2018-01-01

    The Pharmacovigilance Risk Assessment Committee (PRAC) of the European Medicines Agency (EMA) earlier this year recommended to suspend some marketing authorisations for Gadolinium Containing Contrast Agents (GCCAs) based on linear chelators due to the potential risk of gadolinium retention in the human body. These recommendations have recently been re-evaluated by EMA's Committee for Medicinal Products for Human Use (CHMP), and confirmed the final opinion of the European Medicines Agency. This editorial provides an overview of the available GCCAs and summarises the recent evidence of gadolinium retention. Moreover, a critical appraisal of the strengths and limitations of the scientific evidence currently available on gadolinium retention is given. (orig.)

  15. Basic study of gadolinium neutron capture therapy for malignant brain tumors

    International Nuclear Information System (INIS)

    Oda, Yoshifumi; Takagaki, Masao; Miyatake, Shin-ichi; Kikuchi, Haruhiko

    1994-01-01

    We measured the time-course of gadolinium take up in 91 brain tumor tissues obtained during surgical operations, and compared those results against measurements of gadolinium concentration changes in serum in 31 cases of both malignant and benign brain tumors. The contents of gadolinium in tissues were measured using the ICP spectroscopic method. The results shown wide variations in each class. In malignant gliomas, the maximum Tumor/Blood (T/B) ratio is around 10-30%, reached in 30-40 minutes after i.v. injection of Gd-DTPA, but it is rapidly excreted from the tissue and decreased to lower than 10% at 60 minutes after the injection. There is no measurable correlation between the tissue concentration of gadolinium and the histological grading of astrocytomas. In the case of meningiomas, T/B ratio is 20-30%, and has a tendency to increase gradually even 60 minutes after administration. In one case of rapid recurrent meningioma, the T/B ratio beyond 100% and became 640% at 85 minutes after the injection. In this case, Gd-NC therapy will promise the best result. The main clinical effect of Gd-NCT is due to the 6.30MeV γ-rays, which have a long pathway, and 1.53MeV high-RBE Auger electron. Intraparenchynal capillaries in the brain usually have a thickness of 3.5μm of endothelial cells. The capillaries occupate about 4% of the area of any cross-sectional plane of the brain. Under these conditions, Gd has full therapeutic effect without damaging either normal brain tissues or vascular components, provided the T/B ratio is kept higher than 10%. The further problem of the Gd-NCT is that (1) Gd is situated exclusively in the extracellular spaces as opposed to intracellular-or intranuclearspaces. The development of Gd compounds which will be incorporated into the nucleus is required. (2) It is necessary to keep a high gadolinium T/B ratio during the whole irradiation period, which is 1-2 hours in a 5MW reactor such as the one being used at Kyoto University. (J.P.N.)

  16. Nephrogenic systemic fibrosis (NSF) and gadolinium-based contrast ...

    African Journals Online (AJOL)

    Nephrogenic systemic fibrosis (NSF), unknown before March 1997 and first described in 2000, is a systemic disorder characterised by widespread tissue fibrosis. The first known case occurred in 1997, after the use of gadolinium-based contrast agents (GBCAs) at high doses in patients with renal failure had become routine.

  17. Kinetics of zigzag domain boundaries in gadolinium molybdate

    International Nuclear Information System (INIS)

    Alekseev, A.N.; Proklov, A.L.; Tikhomirova, N.A.; Shuvalov, L.A.; AN SSSR, Moscow. Inst. Kristallografii)

    1987-01-01

    Kinetics of zigzag domain boundaries (3DB) in ferroelectric gadolinium molybdate (GMO) crystal was investigated at different amplitude, duration and growth rate of external electric field. The results verify the difference between shifting rates of two 3DB constituents of wedge-shaped systems, growing with field change rate increase

  18. Synthesis and crystal structure of terbium(III) meta-oxoborate Tb(BO{sub 2}){sub 3} ({identical_to} TbB{sub 3}O{sub 6}); Synthese und Kristallstruktur von Terbium(III)-meta-Oxoborat Tb(BO{sub 2}){sub 3} ({identical_to} TbB{sub 3}O{sub 6})

    Energy Technology Data Exchange (ETDEWEB)

    Nikelski, Tanja; Schleid, Thomas [Institut fuer Anorganische Chemie der Universitaet Stuttgart (Germany)

    2003-06-01

    The terbium meta-oxoborate Tb(BO{sub 2}){sub 3} ({identical_to} TbB{sub 3}O{sub 6}) is obtained as single crystals by the reaction of terbium, Tb{sub 4}O{sub 7} and TbCl{sub 3} with an excess of B{sub 2}O{sub 3} in gastight sealed platinum ampoules at 950 C after three weeks. The compound appears to be air- and water-resistant and crystallizes as long, thin, colourless needles which tend to growth-twinning due to their marked fibrous habit. The crystal structure of Tb(BO{sub 2}){sub 3} (orthorhombic, Pnma; a = 1598.97(9), b = 741.39(4), c = 1229.58(7) pm; Z = 16) contains strongly corrugated oxoborate layers {sub {infinity}}{sup 2}{l_brace}(BO{sub 2}){sup -}{r_brace} built of vertex-linked [BO{sub 4}]{sup 5-} tetrahedra (d(B-O) = 143 - 154 pm, and angsph;(O-B-O) = 102-115 ) which spread out parallel (100). The four crystallographically different Tb{sup 3+} cations all exhibit coordination numbers of eight towards the oxygen atoms (d(Tb-O) = 228-287 pm). The corresponding metal cation polyhedra [TbO{sub 8}]{sup 13+} too convene to layers (composition: {sub {infinity}}{sup 2}{l_brace}(Tb{sub 2}O{sub 11}){sup 16-}{r_brace}) which are likewise oriented parallel to the (100) plane. (Abstract Copyright [2003], Wiley Periodicals, Inc.) [German] Das Terbium-meta-Oxoborat Tb(BO{sub 2}){sub 3} ({identical_to} TbB{sub 3}O{sub 6}) entsteht einkristallin bei der Reaktion von Terbium, Tb{sub 4}O{sub 7} und TbCl{sub 3} mit einem Ueberschuss von B{sub 2}O{sub 3} in gasdicht verschlossenen Platinampullen nach drei Wochen bei 950 C. Die Verbindung ist luft- und wasserstabil und faellt in langen, duennen, farblosen Nadeln an, die aufgrund ihres ausgepraegt faserigen Habitus zur Wachstumsverzwillingung neigen. Die Kristallstruktur von Tb(BO{sub 2}){sub 3} (orthorhombisch, Pnma; a = 1598, 97(9), b = 741, 39(4), c = 1229, 58(7) pm; Z = 16) enthaelt parallel (100) verlaufende, stark gewellte Oxoborat-Schichten {sub {infinity}}{sup 2}{l_brace}(BO{sub 2}){sup -}{r_brace} aus

  19. Nephrogenic systemic fibrosis after application of gadolinium-based contrast agents - a status paper

    International Nuclear Information System (INIS)

    Heinrich, M.; Uder, M.

    2007-01-01

    Recently the association of a rare disease named ''nephrogenic systemic fibrosis'' (NSF) with the administration of gadolinium-containing contrast media, especially gadodiamide (Omniscan, GE-Healthcare), was described. NSF is a scleroderma-like disease characterised by widespread tissue fibrosis. Until now, NSF cases were observed only in patients with kidney disease. Almost all patients were suffering from chronic renal insufficiency, 90 % of them required renal replacement therapy. The true incidence of the disease is unknown. First retrospective analyses of selected collectives of patients with end-stage renal disease showed 2 - 5 % cases of NSF after administration of Gadolinium-containing contrast agents with an odds ratio of 20 - 50 in comparison to non-exposed controls. NSF is a serious adverse reaction, which may result in severe disabilities and even death. Therefore all radiologists applying gadolinium-based contrast agents should be informed about this disease and the recent recommendations for its prevention. On the basis of the published data, Omniscan should not be used in patients with severe renal impairment (GFR 2 ) and those who have had or are undergoing liver transplantation. In neonates and infants up to 1 year of age, Omniscan should only be used after careful consideration. Also the other gadolinium-based contrast agents should be used in high-risk patients only after careful consideration using the lowest dose possible

  20. Clinical impact of gadolinium in the MRI diagnosis of musculoskeletal infection in children

    Energy Technology Data Exchange (ETDEWEB)

    Kan, J.H.; Young, Robert S.; Hernanz-Schulman, Marta [Vanderbilt University, Department of Radiology and Radiological Sciences, Vanderbilt Children' s Hospital, Nashville, TN (United States); Yu, Chang [Vanderbilt University, Department of Biostatistics, Nashville, TN (United States)

    2010-07-15

    The incremental value of gadolinium in the diagnosis of musculoskeletal infection by MRI is controversial. To compare diagnostic utility of noncontrast with contrast MRI in the evaluation of pediatric musculoskeletal infections. We reviewed 90 gadolinium-enhanced MRIs in children with suspected musculoskeletal infection. Noncontrast and contrast MRI scans were evaluated to determine sensitivity and specificity in the diagnosis of musculoskeletal infection and identification of abscesses. Pre- and post-contrast diagnosis of osteomyelitis sensitivity was 89% and 91% (P = 1.00) and specificity was 96% and 96% (P = 1.00), respectively; septic arthritis sensitivity was 50% and 67% (P = 1.00) and specificity was 98% and 98% (P = 1.00), respectively; cellulitis/myositis sensitivity was 100% and 100% (P = 1.00) and specificity was 84% and 88% (P = 0.59), respectively; abscess for the total group was 22 (24.4%) and 42 (46.6%), respectively (P < 0.0001). Abscesses identified only on contrast sequences led to intervention in eight additional children. No child with a final diagnosis of infection had a normal pre-contrast study. Intravenous gadolinium should not be routinely administered in the imaging work-up of nonspinal musculoskeletal infections, particularly when pre-contrast images are normal. However, gadolinium contrast significantly increases the detection of abscesses, particularly small ones that might not require surgical intervention. (orig.)

  1. Clinical impact of gadolinium in the MRI diagnosis of musculoskeletal infection in children

    International Nuclear Information System (INIS)

    Kan, J.H.; Young, Robert S.; Hernanz-Schulman, Marta; Yu, Chang

    2010-01-01

    The incremental value of gadolinium in the diagnosis of musculoskeletal infection by MRI is controversial. To compare diagnostic utility of noncontrast with contrast MRI in the evaluation of pediatric musculoskeletal infections. We reviewed 90 gadolinium-enhanced MRIs in children with suspected musculoskeletal infection. Noncontrast and contrast MRI scans were evaluated to determine sensitivity and specificity in the diagnosis of musculoskeletal infection and identification of abscesses. Pre- and post-contrast diagnosis of osteomyelitis sensitivity was 89% and 91% (P = 1.00) and specificity was 96% and 96% (P = 1.00), respectively; septic arthritis sensitivity was 50% and 67% (P = 1.00) and specificity was 98% and 98% (P = 1.00), respectively; cellulitis/myositis sensitivity was 100% and 100% (P = 1.00) and specificity was 84% and 88% (P = 0.59), respectively; abscess for the total group was 22 (24.4%) and 42 (46.6%), respectively (P < 0.0001). Abscesses identified only on contrast sequences led to intervention in eight additional children. No child with a final diagnosis of infection had a normal pre-contrast study. Intravenous gadolinium should not be routinely administered in the imaging work-up of nonspinal musculoskeletal infections, particularly when pre-contrast images are normal. However, gadolinium contrast significantly increases the detection of abscesses, particularly small ones that might not require surgical intervention. (orig.)

  2. Gadolinium-based Contrast Media, Cerebrospinal Fluid and the Glymphatic System: Possible Mechanisms for the Deposition of Gadolinium in the Brain.

    Science.gov (United States)

    Taoka, Toshiaki; Naganawa, Shinji

    2018-04-10

    After Kanda's first report in 2014 on gadolinium (Gd) deposition in brain tissue, a considerable number of studies have investigated the explanation for the observation. Gd deposition in brain tissue after repeated administration of gadolinium-based contrast medium (GBCM) has been histologically proven, and chelate stability has been shown to affect the deposition. However, the mechanism for this deposition has not been fully elucidated. Recently, a hypothesis was introduced that involves the 'glymphatic system', which is a coined word that combines 'gl' for glia cell and 'lymphatic' system. According to this hypothesis, the perivascular space functions as a conduit for cerebrospinal fluid to flow into the brain parenchyma. The perivascular space around the arteries allows cerebrospinal fluid to enter the interstitial space of the brain tissue through water channels controlled by aquaporin 4. The cerebrospinal fluid entering the interstitial space clears waste proteins from the tissue. It then flows into the perivascular space around the vein and is discharged outside the brain. In addition to the hypothesis regarding the glymphatic system, some reports have described that after GBCM administration, some of the GBCM distributes through systemic blood circulation and remains in other compartments including the cerebrospinal fluid. It is thought that the GBCM distributed into the cerebrospinal fluid cavity via the glymphatic system may remain in brain tissue for a longer duration compared to the GBCM in systemic circulation. Glymphatic system may of course act as a clearance system for GBCM from brain tissue. Based on these findings, the mechanism for Gd deposition in the brain will be discussed in this review. The authors speculate that the glymphatic system may be the major contributory factor to the deposition and clearance of gadolinium in brain tissue.

  3. Nuclear magnetic resonance diagnosis of cerebral tumours with the use of the contrast medium gadolinium-DTPA

    International Nuclear Information System (INIS)

    Schoerner, W.; Felix, R.; Claussen, C.; Fiegler, W.; Kazner, E.; Speck, U.; Niendorf, H.P.

    1984-01-01

    This study examines the effect of the NMR contrast medium gadolinium-DTPA on image contrast in cerebral tumours. Sixteen patients with space-occupying cerebral lesions were examined on a 0.35 Tesla superconducting scanner, using a T1-weighted spinecho sequence prior to and after the intravenous application of gadolinium-DTPA. In 8 patients T2-weighted spinecho-sequences were obtained before the administration of contrast. The tomograms were evaluated visually and according to quantitative criteria. The use of gadolinium-DTPA helps to evaluate the blood-brain barrier and improves diagnosis by differentiating tumour tissue from edema and from normal brain tissue. (orig.) [de

  4. Theoretical study of hyperfine fields due to S-P and transition impurities in gadolinium matrix

    International Nuclear Information System (INIS)

    Santos Leal, C.E. dos.

    1985-01-01

    This work presents a systematic theoretical study for the hyperfine field due to diluted s-p-and transition impurities in metallic gadolinium matrices. The peculiarities de a gadolinium matrix are shown, they are characterized by a semi-completed 4f-shell, which is far from (below) the energetic levels such as the type s-p and d-conduction bands. (author)

  5. Accumulation of MRI contrast agents in malignant fibrous histiocytoma for gadolinium neutron capture therapy

    International Nuclear Information System (INIS)

    Fujimoto, T.; Ichikawa, H.; Akisue, T.; Fujita, I.; Kishimoto, K.; Hara, H.; Imabori, M.; Kawamitsu, H.; Sharma, P.; Brown, S.C.; Moudgil, B.M.; Fujii, M.; Yamamoto, T.; Kurosaka, M.; Fukumori, Y.

    2009-01-01

    Neutron-capture therapy with gadolinium (Gd-NCT) has therapeutic potential, especially that gadolinium is generally used as a contrast medium in magnetic resonance imaging (MRI). The accumulation of gadolinium in a human sarcoma cell line, malignant fibrosis histiocytoma (MFH) Nara-H, was visualized by the MRI system. The commercially available MRI contrast medium Gd-DTPA (Magnevist, dimeglumine gadopentetate aqueous solution) and the biodegradable and highly gadopentetic acid (Gd-DTPA)-loaded chitosan nanoparticles (Gd-nanoCPs) were prepared as MRI contrast agents. The MFH cells were cultured and collected into three falcon tubes that were set into the 3-tesra MRI system to acquire signal intensities from each pellet by the spin echo method, and the longitudinal relaxation time (T1) was calculated. The amount of Gd in the sample was measured by inductively coupled plasma atomic emission spectrography (ICP-AES). The accumulation of gadolinium in cells treated with Gd-nanoCPs was larger than that in cells treated with Gd-DTPA. In contrast, and compared with the control, Gd-DTPA was more effective than Gd-nanoCPs in reducing T1, suggesting that the larger accumulation exerted the adverse effect of lowering the enhancement of MRI. Further studies are warranted to gain insight into the therapeutic potential of Gd-NCT.

  6. Critical Questions Regarding Gadolinium Deposition in the Brain and Body After Injections of the Gadolinium-Based Contrast Agents, Safety, and Clinical Recommendations in Consideration of the EMA's Pharmacovigilance and Risk Assessment Committee Recommendation for Suspension of the Marketing Authorizations for 4 Linear Agents.

    Science.gov (United States)

    Runge, Val M

    2017-06-01

    For magnetic resonance, the established class of intravenous contrast media is the gadolinium-based contrast agents. In the 3 decades since initial approval, these have proven in general to be very safe for human administration. However, in 2006, a devastating late adverse reaction to administration of the less stable gadolinium-based contrast agents was identified, nephrogenic systemic fibrosis. The result of actions taken by the European Medicines Agency and the US Food and Drug Administration, stratifying the agents by risk and contraindicating specific agents in severe renal dysfunction, has led to no new cases being identified in North America or Europe. Subsequently, in 2014, long-term deposition in the brain of gadolinium was first shown, after administration of 2 nonionic linear chelates, gadodiamide, and gadopentetate dimeglumine. This has led to an intense focus on the question of in vivo distribution, possible dechelation, and subsequent deposition of gadolinium, together with substantial clarification of the phenomenon as well as stratification of the agents on this basis. This review focuses on 8 critical questions regarding gadolinium deposition in the brain and body, with the answers and discussion therein important for future regulatory decisions and clinical practice. It is now clear that dechelation of gadolinium occurs in vivo with the linear agents and is responsible for this phenomenon, with key experts in the field recommending, except where there is no suitable alternative, a shift in clinical practice from the linear to macrocyclic agents. In addition, on March 10, 2017, the Pharmacovigilance and Risk Assessment Committee of the European Medicines Agency recommended suspension of the marketing authorization for 4 linear gadolinium contrast agents-specifically Omniscan, Optimark, Magnevist, and MultiHance (gadodiamide, gadoversetamide, gadopentetate dimeglumine, and gadobenate dimeglumine)-for intravenous injection. Cited in the report was

  7. Fumonisin B{sub 1} hepatotoxicity in mice is attenuated by depletion of Kupffer cells by gadolinium chloride

    Energy Technology Data Exchange (ETDEWEB)

    He, Quanren [Department of Physiology and Pharmacology, College of Veterinary Medicine, The University of Georgia, Athens, GA 30602-7389 (United States); Kim, Jiyoung [Department of Physiology and Pharmacology, College of Veterinary Medicine, The University of Georgia, Athens, GA 30602-7389 (United States); Sharma, Raghubir P [Department of Physiology and Pharmacology, College of Veterinary Medicine, The University of Georgia, Athens, GA 30602-7389 (United States)

    2005-02-01

    Fumonisin B{sub 1} (FB{sub 1}) is a toxic and carcinogenic mycotoxin produced by Fusarium verticillioides found on corn worldwide. The biological effects of FB{sub 1} are attributed to sphingolipid metabolism disruption as a result of ceramide synthase inhibition. Tumor necrosis factor {alpha} (TNF{alpha}) is an important modulator of FB{sub 1} hepatotoxicity. Kupffer cells are major source of cytokine production in liver. In the present study we investigated the effects of Kupffer cell depletion by gadolinium on FB{sub 1} hepatotoxicity in female BALB/c mice. Mice were given saline or 50 mg/kg of gadolinium chloride once via the tail vein; 16 h later they were treated with subcutaneous injections of vehicle or 2.25 mg/kg/day FB{sub 1} in saline for three successive days. Gadolinium significantly attenuated FB{sub 1}-induced increases in the activities of circulating alanine aminotransferase and aspartate aminotransferase and reduced the FB{sub 1}-induced hepatocyte apoptosis and free sphinganine accumulation in liver. Both gadolinium and FB{sub 1} treatments individually increased the expression of selected cell signal factors; e.g., TNF{alpha}, TNF receptor 1, TNF-related apoptosis-inducing ligand, lymphotoxin {beta}, interferon {gamma}, and transforming growth factor {beta}1; gadolinium chloride did not alter FB{sub 1}-induced expression of the above genes. Results indicated that Kupffer cells play a role in FB{sub 1} hepatotoxicity. Decreased FB{sub 1}-induced sphinganine accumulation and increased protective TNF{alpha} signaling by gadolinium chloride may in part account for its ameliorating effect on FB{sub 1} liver damage.

  8. Visualization of isolated trigeminal nerve invasion by lymphoma using gadolinium-enhanced magnetic resonance imaging

    International Nuclear Information System (INIS)

    Manon-Espaillat, R.; Lanska, D.J.; Ruff, R.L.; Cleveland Veteran's Administration Medical Center, OH; Case Western Reserve Univ., Cleveland, OH; Masaryk, T.; University Hospitals of Cleveland, OH; Case Western Reserve Univ., Cleveland, OH

    1990-01-01

    A 50-year-old man with active histiocytic lymphoma for 12 years developed an isolated right trigeminal neuropathy. Initial evaluation with head computed tomography, X-rays of the skull base, bone scan, and cerebrospinal fluid analysis including cytology were normal. Gadolinium-enhanced magnetic resonance imaging (MRI) showed enlargement of the proximal third of the right trigeminal nerve. Gadolinium-enhanced MRI can be useful for the early demonstration of cranial nerve invasion by lymphoma. (orig.)

  9. The Effect of Pressure and Temperature on Separation of Free Gadolinium(III) From Gd-DTPA Complex by Nanofiltration-Complexation Method

    Science.gov (United States)

    Rahayu, Iman; Anggraeni, Anni; Ukun, MSS; Bahti, Husein H.

    2017-05-01

    Nowdays, the utilization of rare earth elements has been carried out widely in industry and medicine, one of them is gadolinium in Gd-DTPA complex is used as a contrast agent in a magnetic resonance imaging (MRI) diagnostic to increase the visual contrast between normal tissue and diseased. Although the stability of a given complex may be high enough, the complexation step couldnot have been completed, so there is possible to gadolinium(III) in the complex compound. Therefore, the function of that compounds should be dangerous because of the toxicity of gadolinium(III) in human body. So, it is necessarry to separate free gadolinium(III) from Gd-DTPA complex by nanofiltration-complexation. The method of this study is complexing of Gd2O3 with DTPA ligand by reflux and separation of Gd-DTPA complex from gadolinium(III) with a nanofiltration membrane on the variation of pressures(2, 3, 4, 5, 6 bars) and temperature (25, 30, 35, 40 °C) and determined the flux and rejection. The results of this study are the higher of pressures and temperatures, permeation flux are increasing and ion rejections are decreasing and gave the free gadolinium(III) rejection until 86.26%.

  10. Deep learning enables reduced gadolinium dose for contrast-enhanced brain MRI.

    Science.gov (United States)

    Gong, Enhao; Pauly, John M; Wintermark, Max; Zaharchuk, Greg

    2018-02-13

    There are concerns over gadolinium deposition from gadolinium-based contrast agents (GBCA) administration. To reduce gadolinium dose in contrast-enhanced brain MRI using a deep learning method. Retrospective, crossover. Sixty patients receiving clinically indicated contrast-enhanced brain MRI. 3D T 1 -weighted inversion-recovery prepped fast-spoiled-gradient-echo (IR-FSPGR) imaging was acquired at both 1.5T and 3T. In 60 brain MRI exams, the IR-FSPGR sequence was obtained under three conditions: precontrast, postcontrast images with 10% low-dose (0.01mmol/kg) and 100% full-dose (0.1 mmol/kg) of gadobenate dimeglumine. We trained a deep learning model using the first 10 cases (with mixed indications) to approximate full-dose images from the precontrast and low-dose images. Synthesized full-dose images were created using the trained model in two test sets: 20 patients with mixed indications and 30 patients with glioma. For both test sets, low-dose, true full-dose, and the synthesized full-dose postcontrast image sets were compared quantitatively using peak-signal-to-noise-ratios (PSNR) and structural-similarity-index (SSIM). For the test set comprised of 20 patients with mixed indications, two neuroradiologists scored blindly and independently for the three postcontrast image sets, evaluating image quality, motion-artifact suppression, and contrast enhancement compared with precontrast images. Results were assessed using paired t-tests and noninferiority tests. The proposed deep learning method yielded significant (n = 50, P 5 dB PSNR gains and >11.0% SSIM). Ratings on image quality (n = 20, P = 0.003) and contrast enhancement (n = 20, P deep learning method, gadolinium dose can be reduced 10-fold while preserving contrast information and avoiding significant image quality degradation. 3 Technical Efficacy: Stage 5 J. Magn. Reson. Imaging 2018. © 2018 International Society for Magnetic Resonance in Medicine.

  11. Heat pretreatment-induced activation of gadolinium surfaces towards the initial precipitation of hydrides

    International Nuclear Information System (INIS)

    Benamar, G.; Schweke, D.; Shamir, N.; Zalkind, S.; Livneh, T.; Danon, A.; Kimmel, G.; Mintz, M.H.

    2010-01-01

    A vacuum heat pretreatment is applied, in order to enhance the reactivity of hydride-forming metals towards hydrogen reaction. For gadolinium, as for other rare-earth metals and some actinides, pretreatment temperatures of about 470 K are sufficient to induce such activation. The different factors that may be involved in that activation mechanism are identified and analyzed for gadolinium and their role is evaluated. It is concluded that the most prominent effect is desorption of surface hydroxyl groups, which impede the dissociative chemisorptions of hydrogen.

  12. Gadolinium Contrast Agent is of Limited Value for Magnetic Resonance Imaging Assessment of Synovial Hypertrophy in Hemophiliacs

    Energy Technology Data Exchange (ETDEWEB)

    Lundin, B.; Berntorp, E.; Pettersson, H.; Wirestam, R.; Jonsson, K.; Staahlberg, F.; Ljung, R. [Dept. of Radiology, Univ Hospital of Lund, Lund (Sweden)

    2007-07-15

    Purpose: To examine the influence of different doses of gadolinium contrast agent on synovial enhancement, to compare magnetic resonance imaging (MRI) findings of synovial hypertrophy and radiographic joint changes in hemophiliacs, and to investigate the value of gadolinium in MRI assessment of synovial hypertrophy in hemophiliacs using dynamic MRI and MRI scoring. Material and Methods: Twenty-one hemophiliacs on prophylactic factor treatment without recent bleeds were subjected to radiography and gadolinium contrast-enhanced dynamic and static MRI of the knee using a standard dose of 0.1 mmol/kg b.w. gadoteridol. In 17 of the patients, the MRI procedure was repeated after a triple dose of gadoteridol. Results: MRI findings of synovial hypertrophy were significantly correlated with Pettersson radiographic scores. In 19 of the 21 MRI investigated joints, administration of contrast agent did not alter the result of the evaluation of synovial hypertrophy. Conclusion: The optimal time interval for volume assessment of synovial hypertrophy after injection of gadolinium contrast agent is dose dependent. Hemophiliacs without recent bleeds have minor to abundant synovial hypertrophy in joints with pronounced radiographic changes. Dynamic MRI is not useful for evaluating hemophilic arthropathy, and gadolinium contrast agent is not routinely indicated for MRI scoring of joints in hemophiliacs.

  13. Gadolinium Contrast Agent is of Limited Value for Magnetic Resonance Imaging Assessment of Synovial Hypertrophy in Hemophiliacs

    International Nuclear Information System (INIS)

    Lundin, B.; Berntorp, E.; Pettersson, H.; Wirestam, R.; Jonsson, K.; Staahlberg, F.; Ljung, R.

    2007-01-01

    Purpose: To examine the influence of different doses of gadolinium contrast agent on synovial enhancement, to compare magnetic resonance imaging (MRI) findings of synovial hypertrophy and radiographic joint changes in hemophiliacs, and to investigate the value of gadolinium in MRI assessment of synovial hypertrophy in hemophiliacs using dynamic MRI and MRI scoring. Material and Methods: Twenty-one hemophiliacs on prophylactic factor treatment without recent bleeds were subjected to radiography and gadolinium contrast-enhanced dynamic and static MRI of the knee using a standard dose of 0.1 mmol/kg b.w. gadoteridol. In 17 of the patients, the MRI procedure was repeated after a triple dose of gadoteridol. Results: MRI findings of synovial hypertrophy were significantly correlated with Pettersson radiographic scores. In 19 of the 21 MRI investigated joints, administration of contrast agent did not alter the result of the evaluation of synovial hypertrophy. Conclusion: The optimal time interval for volume assessment of synovial hypertrophy after injection of gadolinium contrast agent is dose dependent. Hemophiliacs without recent bleeds have minor to abundant synovial hypertrophy in joints with pronounced radiographic changes. Dynamic MRI is not useful for evaluating hemophilic arthropathy, and gadolinium contrast agent is not routinely indicated for MRI scoring of joints in hemophiliacs

  14. Comparison of RSYST and WIMSD-4 performance for gadolinium poisoned lattices

    Energy Technology Data Exchange (ETDEWEB)

    Kulikowska, T; Szczesna, B; Sadowska, B

    1992-06-01

    The participation in the Co-ordinated Research Programme on `Safe Core Management with Burnable Absorbers in VVERs` has created a possibility of validation of our basic calculational tools for advanced lattice calculations. A systematic analysis of the performance of WIMSD-4 and the recently adapted RSYST modular systems has been carried out on the basis of two benchmarks with gadolinium bearing pins. The report consists of a detailed comparison of methods and models available in RSYST and WIMSD-4 followed by calculational results and their discussion. Finally, the conclusions are drawn concerning the applicability of the two codes for clean fuel and gadolinium poisoned reactor lattices. (author). 26 refs, 19 figs, 19 tabs.

  15. Phantom experiment of depth-dose distributions for gadolinium neutron capture therapy

    International Nuclear Information System (INIS)

    Matsumoto, T.; Kato, K.; Sakuma, Y.; Tsuruno, A.; Matsubayashi, M.

    1993-01-01

    Depth-dose distributions in a tumor simulated phantom were measured for thermal neutron flux, capture gamma-ray and internal conversion electron dose rates for gadolinium neutron capture therapy. The results show that (i) a significant dose enhancement can be achieved in the tumor by capture gamma-rays and internal conversion electrons but the dose is mainly due to capture gamma-rays from the Gd(n, γ) reactions, therefore, is not selective at the cellular level, (ii) the dose distribution was a function of strongly interrelated parameters such as gadolinium concentrations, tumor site and neutron beam size (collimator aperture size), and (iii) the Gd-NCT by thermal neutrons appears to be a potential for treatment of superficial tumor. (author)

  16. Clinical application of gadolinium-enhanced three-dimensional pulmonary MR angiography

    International Nuclear Information System (INIS)

    Takano, Katsuyuki

    1999-01-01

    Twenty-nine patients with suspected pulmonary lesions, and three normal volunteers, underwent gadolinium-enhanced three-dimensional (3D) pulmonary MR angiography (MRA). The MRA were obtained during intravenous administration of gadolinium-based contrast material, in a single breath-hold. Conspicuity of the normal pulmonary segmental arteries was estimated on the MRA. Abnormal findings such as ''vascular involvement'', ''abnormal connection'', stenosis'', or ''dilatation'' on the MRA were compared with those on conventional angiography or CT. Normal pulmonary segmental arteries, except for A 4,5,6,8and9 of the left pulmonary artery, could be clearly visualized. Blind reading of four different findings lead to characteristic findings for each pulmonary disease that can be aid in their differential diagnoses. This technique shows promise as a noninvasive diagnosis of lung diseases. (author)

  17. Study of points defects produced by irradiation of monocrystalline nickel and polycrystalline gadolinium; Etude des defauts ponctuels crees par irradiation dans: - le nickel monocristallin - le gadolinium polycristallin

    Energy Technology Data Exchange (ETDEWEB)

    Cope, R [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1969-07-01

    The work described in this thesis falls into two parts: the first comprises a study of magnetocrystalline nickel by resistivity measurements; the second is a description of resistivity and magnetic after effect measurements on an h.c.p. ferromagnetic crystal other than cobalt, namely gadolinium. For the first part we have demonstrated the existence of a small but definite orientation dependence in the creation of point defects by electron irradiation (20 deg. K) of a nickel single crystal. In particular, the effect is manifested in the form of the stage I{sub C}, II and III in the resistivity recovery. In the second part an important result has emerged: namely that there is no magnetic after effect phenomenon in a neutron irradiated (27 deg. K) ferromagnetic metal. Several considerations are discussed by way of a preliminary interpretation of this important difference between gadolinium and cobalt. (author) [French] Le travail qui a fait l'objet de ce memoire comporte deux parties distinctes: une premiere constituee de l'etude du nickel sous la forme de monocristaux, a l'aide de mesures de resistivite; la seconde partie est composee d'experiences de resistivite et de trainage magnetique sur un cristal h.c.p. ferromagnetique autre que le cobalt, le gadolinium. Dans la premiere partie, nous avons mis en evidence un effet sensible de la direction de l'irradiation electronique (a 20 deg. K) sur la creation des defauts ponctuels dans le nickel monocristallin, en particulier au niveau des stades I{sub C}, II et III des courbes de revenu de la resistivite. Dans la deuxieme partie, un point particulier a ete mis en evidence: l'absence de phenomene de trainage magnetique dans un metal ferromagnetique irradie par des neutrons (a 27 deg. K). Quelques points d'interpretations preliminaires sont avances pour expliquer la difference notable entre le gadolinium et le cobalt. (auteur)

  18. Determination of integrated neutron flux by the measurement of the isotopic ratios of cadmium and gadolinium

    International Nuclear Information System (INIS)

    Tomiyoshi, Irene Akemy

    1982-01-01

    In this work, the possibility of the indirect determination of the integrated neutron flux, through the change of isotopic ratios of cadmium and gadolinium was investigated. The samples of cadmium we/e gadolinium were irradiated in the IEA-Rl reactor. These elements were chosen because they have high thermal neutron absorption cross section which permit the change in the isotopic composition during a short irradiation time to be measured accurately. The isotopic ratios were measured with a thermionic mass spectrometer the silica-gel technique and arrangement with single filament were used for the cadmium analysis, where as the oxi - reduction technique and arrangement with double filaments were used for gadolinium analysis. The mass fractionation effects for cadmium and gadolinium were corrected respectively by the exponential and potential expansion of the isotopic fractionation factor per atomic mass unit. The flux values supplied by the Centro de Operacao e Utilizacao do Reator de Pesquisas do IPEN were extrapolated. These values and the integrated flux values obtained experimentally were compared. (author)

  19. Hyperfine coupling in gadolinium-praseodymium alloys by specific heat measurements; Etude du couplage hyperfin dans les alliages gadolinium-praseodyme par mesures de chaleur specifique

    Energy Technology Data Exchange (ETDEWEB)

    Michel, J [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1967-12-01

    We have studied the hyperfine coupling in gadolinium-praseodymium alloys by specific heat measurements down to 0.3 K. In the first part we describe the apparatus used to perform our measurements. The second part is devoted to some theoretical considerations. We have studied in detail the case of praseodymium which is an exception in the rare earth series. The third part shows the results we have obtained. (author) [French] Nous avons etudie le couplage hyperfin d'alliages de gadolinium-praseodyme par des mesures de chaleur specifique jusqu'a 0.3 K. Dans la premiere partie de cette etude nous decrivons le dispositif experimental. La deuxieme partie est consacree a des considerations theoriques. Nous avons etudie en detail le cas du praseodyme qui est une exception dans la serie des terres rares. La troisieme partie est consacree aux resultats experimentaux. (auteur)

  20. Experimental and thermodynamic study of the erbium-oxygen-zirconium and gadolinium-oxygen-zirconium systems

    International Nuclear Information System (INIS)

    Jourdan, J.

    2009-11-01

    This work is a contribution to the development of innovative concepts for fuel cladding in pressurized water nuclear reactors. This concept implies the insertion of rare earth (erbium and gadolinium) in the zirconium fuel cladding. The determination of phase equilibria in the systems is essential prior to the implementation of such a promising solution. This study consisted in an experimental determination of the erbium-zirconium phase diagram. For this, we used many different techniques in order to obtain diagram data such as solubility limits, solidus, liquidus or invariant temperatures. These data allowed us to present a new diagram, very different from the previous one available in the literature. We also assessed the diagram using the CALPHAD approach. In the gadolinium-zirconium system, we determined experimentally the solubility limits. Those limits had never been determined before, and the values we obtained showed a very good agreement with the experimental and assessed versions of the diagram. Because these alloys are subjected to oxygen diffusion throughout their life, we focused our attention on the erbium-oxygen-zirconium and gadolinium-oxygen-zirconium systems. The first system has been investigated experimentally. The alloys fabrication has been performed using powder metallurgy. In order to obtain pure raw materials, we fabricated powder from erbium and zirconium bulk metals using hydrogen absorption/desorption. The characterisation of the ternary pellets allowed the determination of two ternary isothermal sections at 800 and 1100 C. For the gadolinium-oxygen-zirconium system, we calculated the phase equilibria at temperatures ranging from 800 to 1100 C, using a homemade database compiled from literature assessments of the oxygen-zirconium, gadolinium-zirconium and gadolinia-zirconia systems. Finally, we determined the mechanical properties, in connexion with the microstructure, of industrial quality alloys in order to identify the influence of

  1. The T2-Shortening Effect of Gadolinium and the Optimal Conditions for Maximizing the CNR for Evaluating the Biliary System: a Phantom Study

    International Nuclear Information System (INIS)

    Lee, Mi Jung; Kim, Myung Joon; Yoon, Choon Sik; Song, Si Young; Park, Kyung Soo; Kim, Woo Sun

    2011-01-01

    Clear depiction of the common bile duct is important when evaluating neonatal cholestasis in order to differentiate biliary atresia from other diseases. During MR cholangiopancreatography, the T2-shortening effect of gadolinium can increase the contrast-to-noise ratio (CNR) of the bile duct and enhance its depiction. The purpose of this study was to confirm, by performing a phantom study, the T2-shortening effect of gadolinium, to evaluate the effect of different gadolinium chelates with different gadolinium concentrations and different magnetic field strengths for investigating the optimal combination of these conditions, and for identifying the maximum CNR for the evaluation of the biliary system. MR imaging using a T2-weighted single-shot fast spin echo sequence and T2 relaxometry was performed with a sponge phantom in a syringe tube. Two kinds of contrast agents (Gd-DTPA and Gd-EOB-DTPA) with different gadolinium concentrations were evaluated with 1.5T and 3T scanners. The signal intensities, the CNRs and the T2 relaxation time were analyzed. The signal intensities significantly decreased as the gadolinium concentrations increased (p < 0.001) with both contrast agents. These signal intensities were higher on a 3T (p < 0.001) scanner. The CNRs were higher on a 1.5T (p < 0.001) scanner and they showed no significant change with different gadolinium concentrations. The T2 relaxation time also showed a negative correlation with the gadolinium concentrations (p < 0.001) and the CNRs showed decrease more with Gd-EOB-DTPA (versus Gd-DTPA; p < 0.001) on a 3T scanner (versus 1.5T; p < 0.001). A T2-shortening effect of gadolinium exhibits a negative correlation with the gadolinium concentration for both the signal intensities and the T2 relaxation time. A higher CNR can be obtained with Gd-DTPA on a 1.5T MRI scanner.

  2. Use of gadolinium-DTPA

    International Nuclear Information System (INIS)

    Bydder, G.

    1990-01-01

    Early in the development of magnetic resonance imaging (MRI) it was apparent that a high level of soft tissue contrast was available de novo and it was thought that the need for externally administered contrast agents might be small. This observation was tempered by the fact that separation of tumor from edema was frequently better with contrast-enhanced X-ray computed tomography (CT) than with unenhanced MRI. It was therefore felt that a contrast agent might be needed for MRI. At the end of 1983 the first parenteral agent, gadolinium diethylene triamine pentaacetic acid (Gd-DTPA) was used in volunteers, and clinical studies began in 1984. This paper discusses how, at present, Gd-DTPA, oral, and intravenous iron compounds are in clinical use

  3. The feasibility study of using deuterated gadolinium nitrate for moderator-poisoned shutdown and excess reactivity control in CANDU reactors

    International Nuclear Information System (INIS)

    Li, J.; Everatt, A.

    2006-01-01

    Gadolinium nitrate is used in CANDU stations as moderator poison for reactor shutdowns and excess reactivity control. The use of the light-water hydrate introduces significant quantities of light water into the moderator system, which must be removed from the moderator by periodically upgrading the moderator (isotopic maintenance). The benefit of using a deuterated gadolinium nitrate would be a higher moderator isotopic and/or a lesser isotopic maintenance requirement. This study evaluated the economics of using deuterated gadolinium nitrate, as opposed to the light-water hydrate, for moderator-poisoned shutdowns and excess reactivity control in CANDU-6 reactors. Normal gadolinium nitrate (i.e., the light-water hydrate) is available from suppliers at ∼125 $/kg. Supplier quotes for deuterated gadolinium nitrate ranged from 1900 to 4000 $/kg. To examine the possibility of producing deuterated gadolinium nitrate in-house at a lower cost than commercially available, a three-stage dissolution/evaporation manufacturing process was conceived and costed. Depending on the assumed demand for the product (i.e., the number of reactors adopting the use of the product) and the capital recovery period, the estimated unit cost for the dissolution/evaporation process ranged from 730 to 2500 $/kg. The determination of economic benefit from using deuterated gadolinium nitrate in existing CANDU stations was based on the cost savings resulting from a higher fuel burn-up (i.e., the higher moderator isotopic would give a higher fuel burn-up). The net benefit of using deuterated gadolinium nitrate for most CANDU stations was determined to be marginal (i.e., <20 k$/a). Only for those CANDU stations where the moderator isotopic was relatively low (e.g., 99.85 wt%) was there a potential significant benefit (20-100 k$/a). However, if the reason for the low moderator isotopic is a relatively high moderator light-water ingress rate from sources other than the use of the light-water hydrate

  4. The experimental and theoretical investigations on the structure of the gadolinium-lead-tellurate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Rada, S., E-mail: Simona.Rada@phys.utcluj.ro [Physics Department, Technical University of Cluj-Napoca, 400641 Cluj-Napoca (Romania); Culea, E.; Rada, M. [Physics Department, Technical University of Cluj-Napoca, 400641 Cluj-Napoca (Romania)

    2011-08-15

    Highlights: {yields} Pronounced affinities of the lead and gadolinium ions towards [TeO{sub 3}] structural units. {yields} The reorganization of the tellurate structural units and the formation of new [Te{sub 3}O{sub 8}]{sup -4} and [Te{sub 6}O{sub 15}]{sup -6} structural units. {yields} Pb{sub 2}Te{sub 3}O{sub 8} and Gd{sub 2}Te{sub 6}O{sub 15} crystalline phases. - Abstract: The purpose of this paper was to approach the structure of gadolinium-lead-tellurate glasses with compositions xGd{sub 2}O{sub 3} (100 - x)[7TeO{sub 2}.3PbO], x = 0-90 mol% using the X-ray diffraction, DFT calculations, FTIR, EPR and UV-VIS spectroscopy. Our results show that the doping with gadolinium ions will deform the Te-O-Te linkages, will affect the length of Te=O bonds and the accommodation of the network with excess of oxygen will be realized by the reorganization of the tellurate structural units. These affinities pronounced of the lead and gadolinium cations towards tellurium atoms yield the formation of the Pb{sub 2}Te{sub 3}O{sub 8} and Gd{sub 2}Te{sub 6}O{sub 15} crystalline phases because tellurate structural units can adopt a variety of structures due to the presence of the lone-pair electrons.

  5. Deposit of isotopically modified gadolinium suitable to detect solar neutrinos

    Energy Technology Data Exchange (ETDEWEB)

    Cribier, M

    1999-04-01

    Consideration on the possibility to find gadolinium with a modified isotopic composition are envisaged, in particular with respect to the important use of this element by the nuclear energy. These possibility could exist in the far future. (author)

  6. Biocompatible Polyhydroxyethylaspartamide-based Micelles with Gadolinium for MRI Contrast Agents

    Directory of Open Access Journals (Sweden)

    Kim Hyo Jeong

    2010-01-01

    Full Text Available Abstract Biocompatible poly-[N-(2-hydroxyethyl-d,l-aspartamide]-methoxypoly(ethyleneglycol-hexadecylamine (PHEA-mPEG-C16 conjugated with 1,4,7,10-tetraazacyclododecan-1,4,7,10-tetraacetic acid-gadolinium (DOTA-Gd via ethylenediamine (ED was synthesized as a magnetic resonance imaging (MRI contrast agent. Amphiphilic PHEA-mPEG-C16-ED-DOTA-Gd forms micelle in aqueous solution. All the synthesized materials were characterized by proton nuclear magnetic resonance (1H NMR. Micelle size and shape were examined by dynamic light scattering (DLS and atomic force microscopy (AFM. Micelles with PHEA-mPEG-C16-ED-DOTA-Gd showed higher relaxivities than the commercially available gadolinium contrast agent. Moreover, the signal intensity of a rabbit liver was effectively increased after intravenous injection of PHEA-mPEG-C16-ED-DOTA-Gd.

  7. First measurements with new high-resolution gadolinium-GEM neutron detectors

    CERN Document Server

    Pfeiffer, Dorothea; Birch, Jens; Etxegarai, Maddi; Hall-Wilton, Richard; Höglund, Carina; Hultman, Lars; Llamas-Jansa, Isabel; Oliveri, Eraldo; Oksanen, Esko; Robinson, Linda; Ropelewski, Leszek; Schmidt, Susann; Streli, Christina; Thuiner, Patrik

    2016-05-17

    European Spallation Source instruments like the macromolecular diffractometer, NMX, require an excellent neutron detection efficiency, high-rate capabilities, time resolution, and an unprecedented spatial resolution in the order of a few hundred micrometers over a wide angular range of the incoming neutrons. For these instruments solid converters in combination with Micro Pattern Gaseous Detectors (MPGDs) are a promising option. A GEM detector with gadolinium converter was tested on a cold neutron beam at the IFE research reactor in Norway. The {\\mu}TPC analysis, proven to improve the spatial resolution in the case of $^{10}$B converters, is extended to gadolinium based detectors. For the first time, a Gd-GEM was successfully operated to detect neutrons with an estimated efficiency of 10% at a wavelength of 2 {\\AA} and a position resolution better than 350 {\\mu}m.

  8. Specific features of the WWER Uranium-Gadolinium fuel behavior at BOL

    International Nuclear Information System (INIS)

    Shcheglov, A.; Proselkov, V.; Volkov, B.

    2013-01-01

    The calculated-experimental analysis of the WWER fuel behavior with 5%wt of gadolinium oxide at the beginning of life (BOL) is presented. The results are based on the data on fuel centerline temperature measurements, gas media pressure inside the cladding and fuel elongation obtained during irradiation of the test fuel rods in HBWR (Halden). Computer analysis of experimental data is performed with TOPRA-2, version 2 code. It is shown that specific features of the uranium-gadolinium fuel behavior at the early of life is due to presence of burnable absorber influencing the average linear heat rating, radial power distribution and lower thermal conductivity. In particular, the analysis of “late” relocation effect on the maximum Gd fuel temperature is presented. (authors)

  9. MRT of experimental liver abscesses - comparison of a new blood pool contrast agent with gadolinium-DTPA

    International Nuclear Information System (INIS)

    Dick, A.; Adam, G.; Spuentrup, E.; Prescher, A.; Muehler, A.; Guenther, R.W.

    1996-01-01

    Purpose: In an experimental pyogenic liver abscess model, the signal intensities were compared intraindividually and interindividually after the application of a new blood pool contrast agent, 24-gadolinium-DTPA (diethylenetriamine-pentaacetic acid) cascade polymer, and after the application of gadopentetate dimeglumine. Methods: In 20 rabbits with experimentally induced liver abscesses, the relative signal intensities of the liver, abscess centre, abscess wall and portal vein were assessed before and between 30 seconds and 60 minutes after injection of a 25 μmol/kg dose of gadolinium polymer and of 100 μmol/kg of gadolinium-DTPA, respectively. Measurements were performed at 1.5 Tesla, using a head coil and a Flash-2-D sequence. Results: The interindividual comparison (unpaired T-test, p [de

  10. Solid solutions of gadolinium doped zinc oxide nanorods by combined microwave-ultrasonic irradiation assisted crystallization

    Science.gov (United States)

    Kiani, Armin; Dastafkan, Kamran; Obeydavi, Ali; Rahimi, Mohammad

    2017-12-01

    Nanocrystalline solid solutions consisting of un-doped and gadolinium doped zinc oxide nanorods were fabricated by a modified sol-gel process utilizing combined ultrasonic-microwave irradiations. Polyvinylpyrrolidone, diethylene glycol, and triethylenetetramine respectively as capping, structure directing, and complexing agents were used under ultrasound dynamic aging and microwave heating to obtain crystalline nanorods. Crystalline phase monitoring, lattice parameters and variation, morphology and shape, elemental analysis, functional groups, reducibility, and the oxidation state of emerged species were examined by PXRD, FESEM, TEM, EDX, FTIR, micro Raman, H2-TPR, and EPR techniques. Results have verified that irradiation mechanism of gelation and crystallization reduces the reaction time, augments the crystal quality, and formation of hexagonal close pack structure of Wurtzite morphology. Besides, dissolution of gadolinium within host lattice involves lattice deformation, unit cell distortion, and angular position variation. Structure related shape and growth along with compositional purity were observed through microscopic and spectroscopic surveys. Furthermore, TPR and EPR studies elucidated more detailed behavior upon exposure to the exerted irradiations and subsequent air-annealing including the formed oxidation states and electron trapping centers, presence of gadolinium, zinc, and oxygen disarrays and defects, as well as alteration in the host unit cell via gadolinium addition.

  11. Clinical experience of gadolinium-DTPA

    International Nuclear Information System (INIS)

    Takemoto, Kazumasa; Inoue, Yuichi; Hashimoto, Hiromi

    1986-01-01

    Magnetic resonance imaging was performed before and after intravenous administration of gadolinium-DTPA (Gd-DTPA) in 9 patients with intracranial tumors (8) and a spinal tumor (1). In this study IR (2100/600) and short SE (600/40) were used. After administration of Gd-DTPA, signal intensity of tumors increased in all cases. Contrast enhanced MRI with Gd-DTPA was useful in metastatic brain tumor, cerebeller astrocytoma and glioblastoma to differentiate the tumor from edema. Since meningiomas were clearly demonstrated and differentiated from edema. Gd-DTPA seems to be not required for the diagnosis of meningiomas. No severe side effect were encountered after injection of Gd-DTPA. (author)

  12. Sensitive and transportable gadolinium-core plastic scintillator sphere for neutron detection and counting

    Energy Technology Data Exchange (ETDEWEB)

    Dumazert, Jonathan; Coulon, Romain; Carrel, Frédérick; Corre, Gwenolé; Normand, Stéphane [CEA, LIST, Laboratoire Capteurs Architectures Electroniques, 91191 Gif-sur-Yvette (France); Méchin, Laurence [CNRS, UCBN, Groupe de Recherche en Informatique, Image, Automatique et Instrumentation de Caen, 14050 Caen (France); Hamel, Matthieu [CEA, LIST, Laboratoire Capteurs Architectures Electroniques, 91191 Gif-sur-Yvette (France)

    2016-08-21

    Neutron detection forms a critical branch of nuclear-related issues, currently driven by the search for competitive alternative technologies to neutron counters based on the helium-3 isotope. The deployment of plastic scintillators shows a high potential for efficient detectors, safer and more reliable than liquids, more easily scalable and cost-effective than inorganic. In the meantime, natural gadolinium, through its 155 and mostly 157 isotopes, presents an exceptionally high interaction probability with thermal neutrons. This paper introduces a dual system including a metal gadolinium core inserted at the center of a high-scale plastic scintillator sphere. Incident fast neutrons are thermalized by the scintillator shell and then may be captured with a significant probability by gadolinium 155 and 157 nuclei in the core. The deposition of a sufficient fraction of the capture high-energy prompt gamma signature inside the scintillator shell will then allow discrimination from background radiations by energy threshold, and therefore neutron detection. The scaling of the system with the Monte Carlo MCNPX2.7 code was carried out according to a tradeoff between the moderation of incident fast neutrons and the probability of slow neutron capture by a moderate-cost metal gadolinium core. Based on the parameters extracted from simulation, a first laboratory prototype for the assessment of the detection method principle has been synthetized. The robustness and sensitivity of the neutron detection principle are then assessed by counting measurement experiments. Experimental results confirm the potential for a stable, highly sensitive, transportable and cost-efficient neutron detector and orientate future investigation toward promising axes.

  13. Sensitive and transportable gadolinium-core plastic scintillator sphere for neutron detection and counting

    International Nuclear Information System (INIS)

    Dumazert, Jonathan; Coulon, Romain; Carrel, Frédérick; Corre, Gwenolé; Normand, Stéphane; Méchin, Laurence; Hamel, Matthieu

    2016-01-01

    Neutron detection forms a critical branch of nuclear-related issues, currently driven by the search for competitive alternative technologies to neutron counters based on the helium-3 isotope. The deployment of plastic scintillators shows a high potential for efficient detectors, safer and more reliable than liquids, more easily scalable and cost-effective than inorganic. In the meantime, natural gadolinium, through its 155 and mostly 157 isotopes, presents an exceptionally high interaction probability with thermal neutrons. This paper introduces a dual system including a metal gadolinium core inserted at the center of a high-scale plastic scintillator sphere. Incident fast neutrons are thermalized by the scintillator shell and then may be captured with a significant probability by gadolinium 155 and 157 nuclei in the core. The deposition of a sufficient fraction of the capture high-energy prompt gamma signature inside the scintillator shell will then allow discrimination from background radiations by energy threshold, and therefore neutron detection. The scaling of the system with the Monte Carlo MCNPX2.7 code was carried out according to a tradeoff between the moderation of incident fast neutrons and the probability of slow neutron capture by a moderate-cost metal gadolinium core. Based on the parameters extracted from simulation, a first laboratory prototype for the assessment of the detection method principle has been synthetized. The robustness and sensitivity of the neutron detection principle are then assessed by counting measurement experiments. Experimental results confirm the potential for a stable, highly sensitive, transportable and cost-efficient neutron detector and orientate future investigation toward promising axes.

  14. Luminescence study on Eu or Tb doped lanthanum-gadolinium pyrosilicate crystal

    Czech Academy of Sciences Publication Activity Database

    Kurosawa, S.; Shishido, T.; Sugawara, T.; Nomura, A.; Yubuta, K.; Pejchal, Jan; Murakami, R.; Yokota, Y.; Shoji, Y.; Ohashi, Y.; Kamada, K.; Yoshikawa, A.

    2015-01-01

    Roč. 41, Mar (2015), s. 80-83 ISSN 0925-3467 Institutional support: RVO:68378271 Keywords : scintillator * gadolinium pyrosilicate Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.183, year: 2015

  15. Long-term retention of gadolinium in the skin of rodents following the administration of gadolinium-based contrast agents

    International Nuclear Information System (INIS)

    Pietsch, Hubertus; Jost, Gregor; Frenzel, Thomas; Huetter, Joachim; Sieber, Martin A.; Lengsfeld, Philipp

    2009-01-01

    Several publications suggest a potential association between the administration of Gadolinium-based contrast agents (GBCAs) and the onset of a rare but serious disease, Nephrogenic Systemic Fibrosis (NSF). The aim of this study was to determine the elimination time-course of Gadolinium (Gd) from skin tissue after application of GBCAs in rats. Seven different marketed GBCAs were injected on five consecutive days at a dose of 2.5 mmol/kg bodyweight into the tail vein of Han-Wistar rats and the Gd concentrations were determined by Inductively Coupled Plasma Mass Spectrometry (ICP-MS) in skin biopsies taken at various time-points up to a year after the last injection. Most of the administered Gd was eliminated from the skin within a time-period of about 2 months. However, the repeated administration of linear GBCAs resulted in long-term retention of a small portion of the administered Gd in the skin tissue of rats, with substantially higher values observed in animals treated with non-ionic linear agents than in those that received ionic linear GBCAs. Following treatment with macrocyclic GBCAs, Gd values in the skin were in the same range as observed in the controls from day 24 post-injection onwards. In summary, we observed a correlation between the complex stability of GBCAs and the amount of residual Gd in the skin up to a year after application of GBCAs. (orig.)

  16. Long-term retention of gadolinium in the skin of rodents following the administration of gadolinium-based contrast agents

    Energy Technology Data Exchange (ETDEWEB)

    Pietsch, Hubertus; Jost, Gregor; Frenzel, Thomas; Huetter, Joachim; Sieber, Martin A. [Media Research, Bayer Schering Pharma AG Contrast, Berlin (Germany); Lengsfeld, Philipp [Bayer Schering Pharma AG, Global Medical Affairs Diagnostic Imaging, Berlin (Germany)

    2009-06-15

    Several publications suggest a potential association between the administration of Gadolinium-based contrast agents (GBCAs) and the onset of a rare but serious disease, Nephrogenic Systemic Fibrosis (NSF). The aim of this study was to determine the elimination time-course of Gadolinium (Gd) from skin tissue after application of GBCAs in rats. Seven different marketed GBCAs were injected on five consecutive days at a dose of 2.5 mmol/kg bodyweight into the tail vein of Han-Wistar rats and the Gd concentrations were determined by Inductively Coupled Plasma Mass Spectrometry (ICP-MS) in skin biopsies taken at various time-points up to a year after the last injection. Most of the administered Gd was eliminated from the skin within a time-period of about 2 months. However, the repeated administration of linear GBCAs resulted in long-term retention of a small portion of the administered Gd in the skin tissue of rats, with substantially higher values observed in animals treated with non-ionic linear agents than in those that received ionic linear GBCAs. Following treatment with macrocyclic GBCAs, Gd values in the skin were in the same range as observed in the controls from day 24 post-injection onwards. In summary, we observed a correlation between the complex stability of GBCAs and the amount of residual Gd in the skin up to a year after application of GBCAs. (orig.)

  17. Design, synthesis, and evaluation of gadolinium cationic lipids as tools for biodistribution studies of gene delivery complexes.

    Science.gov (United States)

    Leclercq, Francoise; Cohen-Ohana, Mirit; Mignet, Nathalie; Sbarbati, Andrea; Herscovici, Jean; Scherman, Daniel; Byk, Gerardo

    2003-01-01

    Gadolinium-chelating cationic lipids have been synthesized to obtain lipoplexes with MRI contrast properties. These compounds were designed to follow the biodistribution of synthetic DNA for gene delivery by nuclear magnetic resonance imaging. The lipid MCO-I-68 was synthesized, and chelate complexes with gadolinium were formed and characterized in terms of physicochemical and DNA binding properties. The transfection activity of MCO-I-68-Gd/DNA complexes was assayed in vitro on NIH 3T3. Different formulations of the product were tested. When up to 5% of the gadolinium lipid complexes were co-formulated with the cationic lipid RPR120535 used as a reference, the transfection levels were maintained as compared to RPR120535 alone. To date, only a liposomal formulation of a gadolinium-cationic lipid chelate without DNA had been observed using magnetic resonance imaging. In vivo intratumoral administration of MCO-I-68-Gd/DNA lipoplexes to tumor model led to an important increase of the NMR signal. It was demonstrated that the new complexes also acted as transfection carriers when they were formulated from liposomes.

  18. Magnetic resonance tomography for focal lesions in the liver using the para-magnetic contrast medium gadolinium DTPA

    International Nuclear Information System (INIS)

    Hamm, B.; Roemer, T.; Felix, R.; Wolf, K.J.; Klinikum Charlottenburg, Berlin

    1986-01-01

    The use of the para-magnetic contrast medium gadolinium DTPA for magnetic resonance tomography of focal lesions in the liver was investigated in 31 patients. Two dosage schedules of the contrast medium (0.1 and 0.2 mmol/kg body weight) were used with field strengths of 0.35 and 0.5 Tesla. Using T 1 sequences, gadolinium DTPA showed increased signal intensity in the liver and in tumours, but this was significantly more marked in the tumour. On T 1 spin-echo sequences, previously iso-intense lesions became visible after administration of contrast. On the other hand, contrast-enhanced lesions were less well seen on inversion recovery sequences because of a reduction in the contrast between tumour and liver tissue. The contrast between tumour and liver tissue was not improved by gadolinium DTPA in comparison with precontrast inversion recovery sequences and T 2 spin-echo sequences. The perfusion of intra-hepatic tumours could be elucidated by magnetic resonance tomography after the administration of gadolinium DTPA. (orig.) [de

  19. Inductively coupled plasma optical emission spectrometry analysis of lanthanum, samarium and gadolinium oxides for rare earths impurities

    International Nuclear Information System (INIS)

    Reino, L.C.P.; Lordello, A.R.

    1990-09-01

    An inductively coupled plasma optical emission spectrometry method is described for the determination of Sm, Eu, La, Gd, Dy, Pr, Ho, Nd, Tb and Y in purified oxides of lanthanum, samarium and gadolinium. The method enables a simple, precise and readily available determination. Dissolution of the samples is achieved with diluted hydrochloric acid (1:1). The solutions are diluted to volume for a concentration of 1mg/ml. The lowest determination limit is 0,01% for most elements and 0,05 or 0,1% for a few rare earths in samarium and gadolinium matrices. Lanthanum, Samarium and Gadolinium concentrates with purity grade of 99,9%, 99,6% and 99,8%, respectively, can be analysed by this procedure. (author)

  20. Gadolinium-DTPA (Magnevist) as a contrast medium for arterial DSA

    International Nuclear Information System (INIS)

    Schild, H.H.; Weber, W.; Boeck, E.; Mildenberger, P.; Strunk, H.; Dueber, C.; Grebe, P.; Schadmand-Fischer, S.; Thelen, M.

    1994-01-01

    16 DSA investigations using intra-arterial Gd-DTPA were performed on 12 patients. The contrast medium was administered either as a 0.5 molar gadolinium solution (commercially available) or diluted with distilled water to a 0.2 -0.4 molar gadolinium solution. The injection was made either by pressure injector or by hand. The aortic arch, abdominal aorta and pelvic and lower limb arteries were examined. 14 of the 16 procedures were diagnostically adequate, but compared with iodinated contrast materials, contrast was less marked. There were no cardiovascular, neurological or allergic side effects. Three patients suffered a feeling of heat and one patient had mild pain during the injection. Even large volumes rapidly injected (up to 20 ml/s of the commercially available solution) were well tolerated. DSA with intra-arterial Gd-DTPA seems to be a suitable alternative for vascular imaging if iodine-containing contrast materials are contraindicated. (orig.) [de

  1. Light deflection in gadolinium molybdate ferroelastic crystals

    International Nuclear Information System (INIS)

    Staniorowski, Piotr; Bornarel, Jean

    2000-01-01

    The deflection of a He-Ne light beam by polydomain gadolinium molybdate (GMO) crystals has been studied with respect to incidence angle α i on the sample at room temperature. The A and B deflected beams do not cross each other during the α i variation, in contrast to results and calculations previously published. The model using the Fresnel equation confirms this result. The model presented is more accurate for numerical calculation than that using the Huygens construction. (author)

  2. Heterobimetallic gadolinium(III)-iron(III) complex of DTPA-bis(3-hydroxytyramide)

    International Nuclear Information System (INIS)

    Parac-Vogt, Tatjana N.; Kimpe, Kristof; Binnemans, Koen

    2004-01-01

    A derivative of diethylenetriamine-N,N,N',N'',N''-pentaacetic acid (DTPA), carrying two catechol functional groups has been synthesised by the reaction between DTPA-bis(anhydride) and 3-hydroxytyramine (dopamine). The ligand DTPA-bis(3-hydroxytyramide), [DTPA(HTA) 2 ], is able to form stable heterobimetallic complexes with gadolinium(III) and iron(III) ions. The gadolinium(III) occupies the internal coordination cage of DTPA formed by three nitrogens, two carboxylate and two amide oxygens, while the [Fe(NTA)(H 2 O) 2 ] (nitrilotriacetic acid, NTA) binds to catechol units by the substitution of two water ligands. The formation of polymeric species was avoided by using the tripodal NTA ligand. The heterobimetallic complex was characterised by means of visible absorption spectroscopy, electron spray ionisation-mass spectrometry (ESI-MS), and nuclear magnetic resonance (NMR) spectroscopy

  3. A case report on a severe anaphylaxis reaction to Gadolinium-based MR contrast media

    Energy Technology Data Exchange (ETDEWEB)

    Park, Juil; Kim, Tae Hyung; Park, Chang Min; Yoon, Soon Ho; Lee, Whal; Kang, Hye Ryun; Choi, Young Hun [Seoul National University Hospital, Seoul (Korea, Republic of)

    2017-02-15

    Acute hypersensitivity reactions to gadolinium-based magnetic resonance (MR) contrast media have been shown to have a much lower incidence and they are generally milder in terms of severity than acute adverse reactions associated with the use of iodinated contrast media for computed tomography scans. However, even though it is rare, a severe hypersensitivity reaction to MR contrast media can occur. Here we present the case of a 66-year-old woman who experienced a severe hypersensitivity reaction after administration of gadolinium-based contrast media without a previous history of allergies.

  4. Standard test methods for chemical and mass spectrometric analysis of nuclear-grade gadolinium oxide (Gd2O3) powder

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2006-01-01

    1.1 These test methods cover procedures for the chemical and mass spectrometric analysis of nuclear-grade gadolinium oxide powders to determine compliance with specifications. 1.2 The analytical procedures appear in the following order: Sections Carbon by Direct CombustionThermal Conductivity C1408 Test Method for Carbon (Total) in Uranium Oxide Powders and Pellets By Direct Combustion-Infrared Detection Method Total Chlorine and Fluorine by Pyrohydrolysis Ion Selective Electrode C1502 Test Method for Determination of Total Chlorine and Fluorine in Uranium Dioxide and Gadolinium Oxide Loss of Weight on Ignition 7-13 Sulfur by CombustionIodometric Titration Impurity Elements by a Spark-Source Mass Spectrographic C761 Test Methods for Chemical, Mass Spectrometric, Spectrochemical,Nuclear, and Radiochemical Analysis of Uranium Hexafluoride C1287 Test Method for Determination of Impurities In Uranium Dioxide By Inductively Coupled Plasma Mass Spectrometry Gadolinium Content in Gadolinium Oxid...

  5. Colloidal stabilization of cerium-gadolinium oxide (CGO) suspensions via rheology

    DEFF Research Database (Denmark)

    Marani, Debora; Sudireddy, Bhaskar Reddy; Bentzen, Janet Jonna

    2015-01-01

    colloidally stable state. The method was applied to explore the ability of four commercial dispersants (acidic affine, neutral, basic affine, and polyvinylpyrrolidone (PVP)) to disperse cerium-gadolinium oxide (CGO) in ethanol. Only the acidic affine and the PVP dispersants were found to efficiently disperse...

  6. Simple method for quantification of gadolinium magnetic resonance imaging contrast agents using ESR spectroscopy.

    Science.gov (United States)

    Takeshita, Keizo; Kinoshita, Shota; Okazaki, Shoko

    2012-01-01

    To develop an estimation method of gadolinium magnetic resonance imaging (MRI) contrast agents, the effect of concentration of Gd compounds on the ESR spectrum of nitroxyl radical was examined. A solution of either 4-oxo-2,2,6,6-tetramethylpiperidine-N-oxyl (TEMPONE) or 4-hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl (TEMPOL) was mixed with a solution of Gd compound and the ESR spectrum was recorded. Increased concentration of gadolinium-diethylenetriamine pentaacetic acid chelate (Gd-DTPA), an MRI contrast agent, increased the peak-to-peak line widths of ESR spectra of the nitroxyl radicals, in accordance with a decrease of their signal heights. A linear relationship was observed between concentration of Gd-DTPA and line width of ESR signal, up to approximately 50 mmol/L Gd-DTPA, with a high correlation coefficient. Response of TEMPONE was 1.4-times higher than that of TEMPOL as evaluated from the slopes of the lines. The response was slightly different among Gd compounds; the slopes of calibration curves for acua[N,N-bis[2-[(carboxymethyl)[(methylcarbamoyl)methyl]amino]ethyl]glycinato(3-)]gadolinium hydrate (Gd-DTPA-BMA) (6.22 μT·L/mmol) and gadolinium-1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid chelate (Gd-DOTA) (6.62 μT·L/mmol) were steeper than the slope for Gd-DTPA (5.45 μT·L/mmol), whereas the slope for gadolinium chloride (4.94 μT·L/mmol) was less steep than that for Gd-DTPA. This method is simple to apply. The results indicate that this method is useful for rough estimation of the concentration of Gd contrast agents if calibration is carried out with each standard compound. It was also found that the plot of the reciprocal square root of signal height against concentrations of contrast agents could be useful for the estimation if a constant volume of sample solution is taken and measured at the same position in the ESR cavity every time.

  7. Extended diagnosis of liver tumor with gadolinium DTPA supplementary to routine procedure in nuclear medicine

    International Nuclear Information System (INIS)

    Ehrenheim, C.; Heintz, P.; Schwarzrock, R.; Schober, O.; Hundeshagen, H.

    1988-01-01

    Several imaging methods and especially their combined application are proven to be useful in the diagnosis and differentiation of liver tumors: Ultrasound, roentgen computed tomography, sequential hepatobiliary scintigraphy (HBSS), blood pool scintigraphy and magnetic resonance imaging. 38 patients with liver tumors (hemangioma, hepatocellular carcinoma, focal nodular hyperplasia) underwent MRI of the liver before and after i.v. injection of 0.2 mmol/kg Gadolinium-DTPA in addition to other imaging methods. Written informed consent we achieved in all cases. The normal and pathological findings in MRI were documented in T1- and T2-weighted images, proton density image, calculated T1- and T2-images and a T1-weighted image after application of the contrast agent. The application of Gadolinium-DTPA as contrast agent improves the delimitation of the most intrahepatic lesions. Concerning the hemangiomas of the liver the improved contrast behaviour induced by Gadolinium-DTPA does not reach the contrast and sensitivity of a native T2-weighted SE image. The demarcation of focal nodular hyperplasia is not improved by use of the contrast agent. This finding supports the assumption that the FNH is not basically different from normal liver tissue. Gadolinium-DTPA provides additional information concerning the delineation of internal tumor details in hepatocellular carcinoma (hyperperfused areas, necroses, fibrous capsular structures). (orig.)

  8. Radiological impact of the use of calcium hydroxylapatite dermal fillers

    International Nuclear Information System (INIS)

    Feeney, J.N.; Fox, J.J.; Akhurst, T.

    2009-01-01

    Aim: To report a case series in which the radiological features of the subcutaneous use of calcium hydroxylapatite (CaHa) dermal fillers are described for the first time. Materials and methods: Five patients with facial hyperattenuating hypermetabolic subcutaneous lesions were identified on 2- [ 18 F]-fluoro-2-deoxy-D-glucose (FDG) positron-emission tomography/computed tomography (PET/CT), who gave a history of facial injections to augment physical appearance. Correlation with additional imaging studies was performed. Results: All cases had subcutaneous high attenuation material on CT (range 280-700 HU), which was FDG avid on PET, with a standardized uptake value (SUV) range of 2.9-13.4. Magnetic resonance imaging (MRI) demonstrated a heterogeneous intermediate signal intensity subcutaneous lesion with enhancement post-gadolinium in one case. Conclusions: CaHa dermal filler is hyperattenuating on CT, hypermetabolic on FDG-PET imaging, of intermediate signal intensity on MRI, and is a potential cause of a false-positive imaging study.

  9. Depletion of gadolinium burnable poison in a PWR assembly with high burnup fuel

    Energy Technology Data Exchange (ETDEWEB)

    Refeat, Riham Mahmoud [Nuclear and Radiological Regulatory Authority (NRRA), Cairo (Egypt). Safety Engineering Dept.

    2015-12-15

    A tendency to increase the discharge burnup of nuclear fuel for Advanced Pressurized Water Reactors (PWR) has been a characteristic of its operation for many years. It will be able to burn at very high burnup of about 70 GWd/t with UO{sub 2} fuels. The U-235 enrichment must be higher than 5 %, which leads to the necessity of using an extremely efficient burnable poison like Gadolinium oxide. Using gadolinium isotope is significant due to its particular depletion behavior (''Onion-Skin'' effect). In this paper, the MCNPX2.7 code is used to calculate the important neutronic parameters of the next generation fuels of PWR. K-infinity, local peaking factor and fission rate distributions are calculated for a PWR assembly which burn at very high burnup reaching 70 GWd/t. The calculations are performed using the recently released evaluated Gadolinium cross section data. The results obtained are close to those of a LWR next generation fuel benchmark problem. This demonstrates that the calculation scheme used is able to accurately model a PWR assembly that operates at high burnup values.

  10. Added diagnostic value of T2-weighted MR imaging to gadolinium-enhanced three-dimensional dynamic MR imaging for the detection of small hepatocellular carcinomas

    International Nuclear Information System (INIS)

    Kim, Young Kon; Lee, Young Hwan; Kim, Chong Soo; Han, Young Min

    2008-01-01

    Purpose: To assess the added value of T2-weighted MRI to gadolinium-enhanced dynamic MRI for detection of HCCs. Materials and methods: Two readers retrospectively analyzed MRIs of 115 patients with 131 HCCs (size; 0.6-2.0 cm) that had been diagnosed by histology (n = 41) or imaging findings (n = 90). Two separate blind image analyses of the gadolinium set and the combined T2-weighted imaging and gadolinium sets were performed. Diagnostic accuracy was evaluated using the alternative-free response receiver operating characteristic method with four-point scale. Sensitivity and positive predictive value were also calculated. Results: For both observers, the Az values and sensitivities with the combined T2-weighed imaging and gadolinium set (mean Az 0.806, sensitivity 84.7) were significantly higher than those with the gadolinium set (mean Az 0.660, sensitivity 59.9) (p < 0.05). The addition of T2-weighted imaging led to a change in diagnosis for 27 lesions by both observers, which at gadolinium set were assigned a confidence level of 1 or 2 but at additional reading of T2-weighted imaging were assigned a confidence level of 3 or 4. For the positive predictive values, each image set showed a similar value for each observer. Conclusion: The addition of T2-weighted imaging to gadolinium-enhanced 3D dynamic imaging could be helpful in the detection of HCC by increasing reader confidence for HCCs with equivocal findings on gadolinium-enhanced MRIs

  11. Study on the thermodynamics of the gadolinium-hydrogen binary system (H/Gd = 0.0–2.0) and implications to metallic gadolinium purification

    Energy Technology Data Exchange (ETDEWEB)

    Fu, Kai; Li, Guoling [Beijing National Laboratory of Molecular Sciences, State Key Laboratory of Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871 (China); Department of Materials Physics and Chemistry, University of Science and Technology Beijing, NO. 30, Xueyuan Road, Beijing 100083 (China); Li, Jigang [Beijing National Laboratory of Molecular Sciences, State Key Laboratory of Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871 (China); Liu, Yang [Department of Food Science, College of Arts and Science, Beijing Union University, Beijing, 100101 (China); Tian, Wenhuai, E-mail: wenhuaitian@ustb.edu.cn [Department of Materials Physics and Chemistry, University of Science and Technology Beijing, NO. 30, Xueyuan Road, Beijing 100083 (China); Zheng, Jie [Beijing National Laboratory of Molecular Sciences, State Key Laboratory of Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871 (China); Li, Xingguo, E-mail: xgli@pku.edu.cn [Beijing National Laboratory of Molecular Sciences, State Key Laboratory of Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871 (China)

    2016-07-15

    The thermodynamics of the gadolinium-hydrogen (Gd–H) binary system (H/Gd = 0.0–2.0) between 650 and 900 °C is studied by pressure composition isotherm measurement. Significant H dissolution in Gd is observed, up to H/Gd = 0.34 at 650 °C and 0.55 at 900 °C. The metal-rich phase boundary of nonstoichiometric gadolinium dihydride was found to occur with nominal composition of GdH{sub 1.80} at 650 °C and GdH{sub 1.53} at 900 °C. The results are in fairly good agreement with previous experimental work but with improved accuracy. The binary phase diagram is obtained using the CALPHAD method. The thermodynamic study here assists the understanding on the efficient deoxygenation effect by the H in Gd for Gd purification. - Highlights: • PCI measurements with high accuracy has been carried out. • A first assessment of Gd–H system has been carried out by the CALPHAD method. • A set of self-consistent thermodynamic parameters was derived for this system.

  12. Coordination chemistry of gadolinium complexes having pyridine carboxylate units in relation with the medical imagery

    International Nuclear Information System (INIS)

    Gateau, C.; Chatterton, N.; Nonat, A.; Mazzanti, M.; Pecaut, J.; Borel, A.; Merbach, A.; Heim, L.

    2005-01-01

    In order to study the influence of the coordination sphere on the properties which govern the relaxivity, ligands containing pyridine carboxylates units have been particularly studied. It has been shown that the tripodal ligand tpaa forms with gadolinium (III) a neutral complex having a relaxivity (r1p=13.3 mM -1 at 298 K and 60 MHz) which is three times superior to the contrast agents currently used in NMR Imaging. To explain this remarkably relaxivity, two new ligands analogous to the tpaa: the tpatcn and the bpeda containing pyridine carboxylate units bound to one or several aliphatic nitrogen have been studied in modulating the number of coordination sites and the symmetry degree. The study of the relaxivity of the corresponding gadolinium (III) complexes gives precious data on the understanding of the results in the case of the complex [Gd(tpaa)]. The synthesis and the properties of these gadolinium (III) complexes will be presented during this conference. (O.M.)

  13. Importance of the use of gadolinium in neurocysticercosis diagnosis

    International Nuclear Information System (INIS)

    Machado Junior, M.A.; Costa, G.; Barbosa, V.A.; Rubin, J.C.

    1994-01-01

    Magnetic Resonance (MRI) and Computed Tomography (CT) features of neurocysticercosis are variable and depend fundamentally on the stage in evolution of the infection, location, number and size of the cysts. The authors retrospectively evaluated MRI obtained on O.5 Tesla superconducting unit in four neurocysticercosis patients and observed new MRI features only after Gadolinium enhancement. (author)

  14. Gadolinium-DTPA: value in MR imaging of extraspinal musculoskeletal infections

    International Nuclear Information System (INIS)

    Haddad, M.C.; Sharif, H.S.; Aabed, M.Y.; Al Shahed, M.S.; Sammak, B.M.; Clark, D.C.

    1993-01-01

    To determine if paramagnetic contrast agents can improve the detection, delineation, and characterization of extraspinal musculoskeletal infections (MSI) on magnetic resonance (MR) imaging, 42 patients with clinical suspicion of MSI underwent MR imaging before and after intravenous administration of gadolinium-DTPA. The lesions consisted of 27 proven infections and 15 noninfective conditions. Specificity and accuracy in identifying infective lesions averaged 80% and 84%, respectively, on precontrast studies and 80% and 89% on the enhanced examinations, with no statistically significant difference. Rim enhancement around abscess loculi was the only pathognomonic sign of infection seen in ten patients with chronic osteomyelitis and pyogenic or tuberculous infections. In 17 patients with acute osteomyelitis, brucellosis, or mycetoma, detection and delineation of the lesions were best on precontrast studies, while postcontrast examinations resulted in underestimation of the extent of abnormalities in all cases. We conclude that intravenous gadolinium-DTPA has limited usefulness in the MR evaluation of extraspinal MSI. (orig.)

  15. Gadolinium-DTPA: value in MR imaging of extraspinal musculoskeletal infections

    Energy Technology Data Exchange (ETDEWEB)

    Haddad, M.C. [Dept. of Radiology, Riyadh Armed Forces Hospital, Riyadh (Saudi Arabia); Sharif, H.S. [Dept. of Radiology, Riyadh Armed Forces Hospital, Riyadh (Saudi Arabia); Aabed, M.Y. [Dept. of Radiology, Riyadh Armed Forces Hospital, Riyadh (Saudi Arabia); Al Shahed, M.S. [Dept. of Radiology, Riyadh Armed Forces Hospital, Riyadh (Saudi Arabia); Sammak, B.M. [Dept. of Radiology, Riyadh Armed Forces Hospital, Riyadh (Saudi Arabia); Clark, D.C. [Dept. of Radiology, Riyadh Armed Forces Hospital, Riyadh (Saudi Arabia)

    1993-12-01

    To determine if paramagnetic contrast agents can improve the detection, delineation, and characterization of extraspinal musculoskeletal infections (MSI) on magnetic resonance (MR) imaging, 42 patients with clinical suspicion of MSI underwent MR imaging before and after intravenous administration of gadolinium-DTPA. The lesions consisted of 27 proven infections and 15 noninfective conditions. Specificity and accuracy in identifying infective lesions averaged 80% and 84%, respectively, on precontrast studies and 80% and 89% on the enhanced examinations, with no statistically significant difference. Rim enhancement around abscess loculi was the only pathognomonic sign of infection seen in ten patients with chronic osteomyelitis and pyogenic or tuberculous infections. In 17 patients with acute osteomyelitis, brucellosis, or mycetoma, detection and delineation of the lesions were best on precontrast studies, while postcontrast examinations resulted in underestimation of the extent of abnormalities in all cases. We conclude that intravenous gadolinium-DTPA has limited usefulness in the MR evaluation of extraspinal MSI. (orig.)

  16. High Signal Intensity in the Dentate Nucleus and Globus Pallidus on Unenhanced T1-Weighted MR Images: Comparison between Gadobutrol and Linear Gadolinium-Based Contrast Agents.

    Science.gov (United States)

    Moser, F G; Watterson, C T; Weiss, S; Austin, M; Mirocha, J; Prasad, R; Wang, J

    2018-02-01

    In view of the recent observations that gadolinium deposits in brain tissue after intravenous injection, our aim of this study was to compare signal changes in the globus pallidus and dentate nucleus on unenhanced T1-weighted MR images in patients receiving serial doses of gadobutrol, a macrocyclic gadolinium-based contrast agent, with those seen in patients receiving linear gadolinium-based contrast agents. This was a retrospective analysis of on-site patients with brain tumors. Fifty-nine patients received only gadobutrol, and 60 patients received only linear gadolinium-based contrast agents. Linear gadolinium-based contrast agents included gadoversetamide, gadobenate dimeglumine, and gadodiamide. T1 signal intensity in the globus pallidus, dentate nucleus, and pons was measured on the precontrast portions of patients' first and seventh brain MRIs. Ratios of signal intensity comparing the globus pallidus with the pons (globus pallidus/pons) and dentate nucleus with the pons (dentate nucleus/pons) were calculated. Changes in the above signal intensity ratios were compared within the gadobutrol and linear agent groups, as well as between groups. The dentate nucleus/pons signal ratio increased in the linear gadolinium-based contrast agent group ( t = 4.215, P linear gadolinium-based contrast agent group ( t = 2.931, P linear gadolinium-based contrast agents. © 2018 by American Journal of Neuroradiology.

  17. Present status of PIK gadolinium control

    International Nuclear Information System (INIS)

    Petrov, Yu.V.; Garusov, E.A.; Shustov, V.A.

    1994-01-01

    A liquid control element (LCE) containing a water solution of gadolinium nitrate Gd(NO 3 ) 3 was originally planned for use at the PIK reactor for partial compensation of poisoning and fuel burnup [1-3]. However, a further analysis has shown that quick forcing-out, boiling up or flowing-out of the absorbing solution (though of low probability) can lead to the dangerous prompt overcriticality of the reactor. The results of the analysis are presented as well as the upper limit of the reactivity, quick insertion of which still is safe for the reactor (J.P.N.)

  18. Prominent porto-systemic collateral pathways in patients with portal hypertension: demonstration by gadolinium-enhanced magnetic resonance angiography

    International Nuclear Information System (INIS)

    Caldana, Rogerio Pedreschi; Bezerra, Alexandre Araujo Sergio; Cecin, Alexnadre Oliveira; Souza, Luis Ronan Marques Ferreira de; Goldman, Susan Menasce; D'Ippolito, Giuseppe; Szejnfeld, Jacob

    2003-01-01

    To demonstrate the usefulness of gadolinium-enhanced magnetic resonance angiography in the evaluation of prominent porto-systemic collateral pathways. We reviewed the images from 40 patients with portal hypertension studied with gadolinium-enhanced magnetic resonance angiography and selected illustrative cases of prominent porto-systemic collateral pathways. The scans were performed using high field equipment (1.5 Tesla) and a 3 D volume technique. Image were obtained after intravenous injection of paramagnetic contrast media using a power injector. Magnetic resonance angiography demonstrated with precision the porto-systemic collateral pathways, particularly when investigating extensive territories or large vessels. The cases presented show the potential of this method in the investigation of patients with portal hypertension. Gadolinium-enhanced magnetic resonance angiography is a useful method for the evaluation of patients with portal hypertension and prominent collateral pathways. (author)

  19. Calcium paradox and calcium entry blockers

    NARCIS (Netherlands)

    Ruigrok, T.J.C.; Slade, A.M.; Nayler, W.G.; Meijler, F.L.

    1984-01-01

    Reperfusion of isolated hearts with calcium-containing solution after a short period of calcium-free perfusion results in irreversible cell damage (calcium paradox). This phenomenon is characterized by an excessive influx of calcium into the cells, the rapid onset of myocardial contracture,

  20. Gadolinium neutron capture brachytherapy (GdNCB), a new treatment method for intravascular brachytherapy

    International Nuclear Information System (INIS)

    Enger, Shirin A.; Rezaei, Arash; Munck af Rosenschoeld, Per; Lundqvist, Hans

    2006-01-01

    Restenosis is a major problem after balloon angioplasty and stent implantation. The aim of this study is to introduce gadolinium neutron capture brachytherapy (GdNCB) as a suitable modality for treatment of stenosis. The utility of GdNCB in intravascular brachytherapy (IVBT) of stent stenosis is investigated by using the GEANT4 and MCNP4B Monte Carlo radiation transport codes. To study capture rate, Kerma, absorbed dose and absorbed dose rate around a Gd-containing stent activated with neutrons, a 30 mm long, 5 mm diameter gadolinium foil is chosen. The input data is a neutron spectrum used for clinical neutron capture therapy in Studsvik, Sweden. Thermal neutron capture in gadolinium yields a spectrum of high-energy gamma photons, which due to the build-up effect gives an almost flat dose delivery pattern to the first 4 mm around the stent. The absorbed dose rate is 1.33 Gy/min, 0.25 mm from the stent surface while the dose to normal tissue is in order of 0.22 Gy/min, i.e., a factor of 6 lower. To spare normal tissue further fractionation of the dose is also possible. The capture rate is relatively high at both ends of the foil. The dose distribution from gamma and charge particle radiation at the edges and inside the stent contributes to a nonuniform dose distribution. This will lead to higher doses to the surrounding tissue and may prevent stent edge and in-stent restenosis. The position of the stent can be verified and corrected by the treatment plan prior to activation. Activation of the stent by an external neutron field can be performed days after catherization when the target cells start to proliferate and can be expected to be more radiation sensitive. Another advantage of the nonradioactive gadolinium stent is the possibility to avoid radiation hazard to personnel

  1. Isotope shifts in odd and even energy levels of the neutral and singly ionised gadolinium atom

    International Nuclear Information System (INIS)

    Ahmad, S.A.; Venugopalan, A.; Saksena, G.D.

    1979-01-01

    Isotope shift studies in the gadolinium spectra have been extended in the region 4140 to 4535 A. Isotope shift Δσ(156 to 160) have been measured in 315 lines of the neutral and singly ionised gadolinium atom using a recording Fabry-Perot Spectrometer and gadolinium samples enriched in 156 Gd and 160 Gd isotopes. Some of the Gd I lines studied involve transitions from newly identified high odd levels of 4f 8 6s6p, 4f 7 5d6s7s and 4f 7 5d 3 configurations to low even levels of 4f 8 6s 2 and 4f 7 6s 2 6p configurations. Electronic configurations of the energy levels have been discussed on the basis of observed isotope shifts. In some cases assigned configurations have been revised and probable configurations have been suggested. (author)

  2. Laser ablation of Bi-substituted gadolinium iron garnet films

    International Nuclear Information System (INIS)

    Watanabe, N.; Hayashida, K.; Kawano, K.; Higuchi, K.; Ohkoshi, M.; Tsushima, K.

    1995-01-01

    Bi-substituted gadolinium iron garnet films were deposited by laser ablation. The composition, the structure and the magnetic properties of the films were found to be strongly dependent both on the compositions of the targets and on the pressure of oxygen. The highest values of Bi-substitution up to x=1.44 with uniform composition were obtained, after annealing in air. ((orig.))

  3. Pineapple juice labeled with gadolinium: a convenient oral contrast for magnetic resonance cholangiopancreatography

    International Nuclear Information System (INIS)

    Coppens, Emmanuel; Metens, Thierry; Winant, Catherine; Matos, Celso

    2005-01-01

    The aim of our study was to prepare in vitro a pineapple juice (PJ) solution labeled with a minimal gadolinium concentration working as a negative contrast agent in heavily T2-weighted imaging and to assess that solution in vivo as a negative oral contrast agent for magnetic resonance cholangiopancreatography (MRCP). Three PJs were compared in vitro according to their T2. Increasing concentrations of gadolinium (Gd)-DOTA in PJ were assessed in vitro for T2 reduction. Single-shot turbo spin echo T2-weighted MR cholangiopancreatograms were obtained for 35 patients with suspected biliopancreatic duct disease, before and after ingestion of the PJ/Gd-DOTA solution. Signal intensity (SI) measurements of gastroduodenal lumens, pancreatobiliary ducts, and image quality scores were obtained systematically before and after contrast ingestion. The in vitro selected Gd-DOTA concentration in the PJ was 2.76 mmol/l. Ingestion of 180 ml of PJ labeled with 1 ml of Gd-DOTA eliminated efficiently the gastroduodenal SI in MRCP, improving significantly the rates of complete visualization of the pancreatobiliary ducts (P<0.01) and the MRCP image quality scores (P<0.05). All patients easily ingested the contrast solution and found the solution palatable. PJ labeled with gadolinium constituted an efficient and convenient negative oral contrast agent for MRCP. (orig.)

  4. Pineapple juice labeled with gadolinium: a convenient oral contrast for magnetic resonance cholangiopancreatography

    Energy Technology Data Exchange (ETDEWEB)

    Coppens, Emmanuel; Metens, Thierry; Winant, Catherine; Matos, Celso [Hopital Erasme, Universite Libre de Bruxelles, Department of Radiology, Division of Magnetic Resonance, Brussels (Belgium)

    2005-10-01

    The aim of our study was to prepare in vitro a pineapple juice (PJ) solution labeled with a minimal gadolinium concentration working as a negative contrast agent in heavily T2-weighted imaging and to assess that solution in vivo as a negative oral contrast agent for magnetic resonance cholangiopancreatography (MRCP). Three PJs were compared in vitro according to their T2. Increasing concentrations of gadolinium (Gd)-DOTA in PJ were assessed in vitro for T2 reduction. Single-shot turbo spin echo T2-weighted MR cholangiopancreatograms were obtained for 35 patients with suspected biliopancreatic duct disease, before and after ingestion of the PJ/Gd-DOTA solution. Signal intensity (SI) measurements of gastroduodenal lumens, pancreatobiliary ducts, and image quality scores were obtained systematically before and after contrast ingestion. The in vitro selected Gd-DOTA concentration in the PJ was 2.76 mmol/l. Ingestion of 180 ml of PJ labeled with 1 ml of Gd-DOTA eliminated efficiently the gastroduodenal SI in MRCP, improving significantly the rates of complete visualization of the pancreatobiliary ducts (P<0.01) and the MRCP image quality scores (P<0.05). All patients easily ingested the contrast solution and found the solution palatable. PJ labeled with gadolinium constituted an efficient and convenient negative oral contrast agent for MRCP. (orig.)

  5. First-pass myocardial perfusion MR imaging with gadolinium-enhanced turbo FLASH

    International Nuclear Information System (INIS)

    Teresi, L.M.; Smith, C.; Messenger, J.; Watanabe, A.; Herbst, M.; O'Sullivan, R.M.; Lee, R.; Remer, J.; Rappaport, A.; Bradley, W.G.

    1990-01-01

    This paper determines the efficacy of MR first-pass myocardial perfusion imaging using gadolinium-enhanced Turbo--fast low-angle shot (FLASH) ultrafast imaging combined with MR systolic wall thickening data for the determination of myocardial viability. Five normal volunteers and five patients with remote myocardial infarction were studied on a 1.5-T imaging system (Siemans, Ehrlangen, NJ). Turbo-FLASH imaging utilized a 180 degrees inversion pulse followed by a rapid gradient-echo sequence (TI 400 msec, TE2 msec, TR 4.9 msec, FA 8 degrees) with a complete 64 x 64 matrix image (300 mm FOV) being acquired in 300 msec. First-pass myocardial perfusion imaging was performed in the short-axis and long-axis oblique projections with a concantenated series of Turbo-FLASH images triggered to end-systole acquired immediately before and during a rapid bolus injection of 5cc gadolinium-DTPA

  6. Dielectric and electrical properties of gadolinium-modified lead-zirconate-titanate system

    International Nuclear Information System (INIS)

    Panigrahi, S.C.; Das, Piyush R.; Parida, B.N.; Padhee, R.; Choudhary, R.N.P.

    2014-01-01

    Highlights: • Gadolinium modified PZT have very good dielectric and ferroelectric properties. • The impedance analysis of shows grain and grain boundary phenomena. • Electrical properties of the compounds show very good transport properties. • Piezoelectric coefficient of the samples have higher values. - Abstract: The gadolinium (Gd) modified lead zirconate titanate (PbZr,TiO 3 ) ceramics with Zr/Ti = 48/52 (i.e., near morphotropic phase boundary (MPB)) in a general chemical formula Pb 1−x Gd x (Zr 0.48 Ti 0.52 ) 1−x/4 O 3 (PGZT; x = 0, 0.07, 0.10 and 0.12) have been synthesized using a high-temperature solid-state reaction method. Preliminary structural analysis using X-ray powder diffraction (XRD) shows the formation of a single-phase tetragonal structure of the compounds. Detailed studies of dielectric parameters of PGZT exhibit the diffuse phase transition but non-relaxor characteristics in the material for the higher concentration of gadolinium. The ac conductivity spectra of PGZT are found to obey Jonscher’s universal power law. The electrical impedance parameters of PGZT (near MPB) were obtained in a wide range of temperature (25–500 °C) and frequency (1–1000 kHz) using complex impedance spectroscopy (CIS) technique. Detailed analysis of these parameters shows that bulk (grain) and grain boundary resistance have significant effect on the total impedance of the materials. Temperature dependence of hysteresis characteristics of PGZT confirms that the phase transition parameter of the material is strongly affected by the substitution of Gd at the Pb-sites

  7. Utility of gadolinium as a contrast medium in endovascular therapeutic procedures; Utilidad del gadolinio como medio de contraste en procedimientos terapeuticos endovasculares

    Energy Technology Data Exchange (ETDEWEB)

    Reyes, R.; Pardo, M. D.; Gorriz, E.; Gallardo, L. (Hospital de Gran Canaria Dr. Negrin); Carreira, J. M. (Universidad de Santiago de Compostela)

    2001-07-01

    To assess the utility of gadolinium associated with CO{sub 2}, as a contrast medium in angiographic studies related to endovascular therapeutic procedures in patients with suboptimal renal function. Between January 2000 and June 2001, endovascular treatments using CO{sub 2} and gadolinium as contrast medium were performed in 10 patients presenting renal function deterioration (creatinine>1.5 mg/ml). A mean dose of 42 ml of gadolinium was administered. The images acquired in diagnostic and therapeutic studied were satisfactory in every case. There was no evidence of significant increases in the previous urea and creatine levels when measured 24, 48 and 72 hours after the procedure. In combination with CO{sub 2} gadolinium is a useful contrast medium for endovascular therapeutic procedures in patients with suboptimal renal function. (Author) 21 refs.

  8. A model of propagating calcium-induced calcium release mediated by calcium diffusion

    NARCIS (Netherlands)

    Backx, P. H.; de Tombe, P. P.; van Deen, J. H.; Mulder, B. J.; ter Keurs, H. E.

    1989-01-01

    The effect of sudden local fluctuations of the free sarcoplasmic [Ca++]i in cardiac cells on calcium release and calcium uptake by the sarcoplasmic reticulum (SR) was calculated with the aid of a simplified model of SR calcium handling. The model was used to evaluate whether propagation of calcium

  9. High-dose gadolinium-enhanced MRI for diagnosis of meningeal metastases

    International Nuclear Information System (INIS)

    Kallmes, D.F.; Gray, L.; Glass, J.P.

    1998-01-01

    We compared high-dose (0.3 mmol/kg) and standard-dose (0.1 mmol/kg) gadolinium-enhanced MRI for diagnosis of meningeal metastases in 12 patients with suspected meningeal metastases. They were imaged with both standard-dose and high-dose gadolinium. All patients with abnormal meningeal enhancement underwent at least one lumbar puncture for cerebrospinal fluid (CSF) cytology, while patients with normal meningeal enhancement were followed clinically. All patients with negative CSF cytology also were followed clinically. A single observer reviewed all the images, with specific attention to the enhancement pattern of the meninges. Abnormal leptomeningeal enhancement was present in three cases, and abnormal pachymeningeal enhancement in three other patients. All of these patients had abnormal CSF analyses. In two of the three cases of abnormal leptomeningeal enhancement the disease was more evident on high-dose than on standard-dose imaging; in one case the abnormal enhancement was visible only on high-dose imaging. In one of the three cases with abnormal pachymeningeal enhancement, the disease was evident prospectively only with high-dose imaging. (orig.)

  10. Development of ICP-MS and ICP-OES methods for determination of gadolinium in samples related to hospital waste water treatment

    Czech Academy of Sciences Publication Activity Database

    Bendakovská, L.; Krejčovská, A.; Černohorský, T.; Zelenková, Jana

    2016-01-01

    Roč. 70, č. 9 (2016), s. 1155-1165 ISSN 0366-6352 Institutional support: RVO:67985874 Keywords : gadolinium * rare-earth elements * bioaccumulation * gadolinium anomaly * inductively coupled plasma mass spectrometry (ICP-MS) * inductively coupled plasma optical emission spectrometry (ICP-OES) Subject RIV: BK - Fluid Dynamics Impact factor: 1.258, year: 2016

  11. Magnetic refrigeration cycle analysis using selected thermodynamic property characterizations for gadolinium gallium garnet

    International Nuclear Information System (INIS)

    Murphy, R.W.

    1992-01-01

    Magneto-thermodynamic property characterizations were selected, adapted, and compared to material property data for gadolinium gallium garnet in the temperature range 4--40 K and magnetic field range 0--6 T. The most appropriate formulations were incorporated into a model in which methods similar to those previously developed for other materials and temperature ranges were used to make limitation and relative performance assessments of Carnot, ideal regenerative, and pseudo-constant field regenerative cycles. Analysis showed that although Carnot cycle limitations on available temperature lift for gadolinium gallium garnet are not as severe as those for materials previously examined, substantial improvements in cooling capacity/temperature lift combinations can be achieved using regenerative cycles within specified fields limits if significant loss mechanisms are mitigated

  12. Comparison between (99m)Tc-diphosphonate imaging and MRI with late gadolinium enhancement in evaluating cardiac involvement in patients with transthyretin familial amyloid polyneuropathy.

    Science.gov (United States)

    Minutoli, Fabio; Di Bella, Gianluca; Mazzeo, Anna; Donato, Rocco; Russo, Massimo; Scribano, Emanuele; Baldari, Sergio

    2013-03-01

    Cardiac involvement is not rare in systemic amyloidosis and is associated with poor prognosis. Both (99m)Tc-diphosphonate imaging and cardiac MRI with late gadolinium enhancement are considered valuable tools in revealing amyloid deposition in the myocardium; however, to our knowledge, no comparative study between the two techniques exists. We compared findings of these two techniques in patients with transthyretin-familial amyloid polyneuropathy (FAP). Eighteen patients with transthyretin-FAP underwent (99m)Tc-diphosphonate imaging and MRI with late gadolinium enhancement. Images were visually evaluated by independent readers to determine the presence of radiotracer accumulation or late gadolinium enhancement-positive areas at the level of cardiac chambers. Interobserver agreement ranged from moderate to very good for (99m)Tc-diphosphonate imaging findings and was very good for findings of MRI with late gadolinium enhancement. Left ventricle (LV) radiotracer uptake was found in 10 of 18 patients, whereas LV late gadolinium enhancement-positive areas were found in eight of 18 patients (χ(2) = 0.9; p = 0.343). One hundred fifty-nine LV segments showed (99m)Tc-diphosphonate accumulation, and 57 LV segments were late gadolinium enhancement positive (p < 0.0001). Radiotracer uptake was found in the right ventricle (RV) in eight patients and in both atria in five patients, whereas MRI showed that RV was involved in three patients and both atria in six patients; the differences were not statistically significant (RV, p = 0.07; atria, p = 1). Intermodality agreement between (99m)Tc-diphosphonate imaging and MRI ranged from fair to good. Our study shows that, although (99m)Tc-diphosphonate imaging and MRI with late gadolinium enhancement have similar capabilities to identify patients with myocardial amyloid deposition, cardiac amyloid infiltration burden can be significantly underestimated by visual analysis of MRI with late gadolinium enhancement compared with (99m

  13. Comparison of predicted with observed biokinetics of inhaled plutonium nitrate and gadolinium oxide in humans

    International Nuclear Information System (INIS)

    Hodgson, A.; Shutt, A.L.; Etherington, G.; Hodgson, S.A.; Rance, E.; Stradling, G.N.; Youngman, M.J.; Ziesenis, A.; Kreyling, W.G.

    2003-01-01

    The absorption kinetics to blood of plutonium and gadolinium after inhalation as nitrate and oxide in humans and animals has been studied. For each material, values describing the time dependence of absorption were derived from the studies in animals and used with the ICRP human respiratory tract model to predict lung retention and cumulative amounts to blood for the volunteers inhaling the same materials. Comparison with the observed behaviour in the volunteers suggests that absorption of plutonium and gadolinium is reasonably species independent, and that data obtained from animal studies can be used to assess their biokinetic behaviour in humans. (author)

  14. Morphological imaging and T2 and T2* mapping of hip cartilage at 7 Tesla MRI under the influence of intravenous gadolinium

    International Nuclear Information System (INIS)

    Lazik-Palm, Andrea; Geis, Christina; Goebel, Juliane; Theysohn, Jens M.; Kraff, Oliver; Johst, Soeren; Ladd, Mark E.; Quick, Harald H.

    2016-01-01

    To investigate the influence of intravenous gadolinium on cartilage T2 and T2* relaxation times and on morphological image quality at 7-T hip MRI. Hips of 11 healthy volunteers were examined at 7 T. Multi-echo sequences for T2 and T2* mapping, 3D T1 volumetric interpolated breath-hold examination (VIBE) and double-echo steady-state (DESS) sequences were acquired before and after intravenous application of gadolinium according to a delayed gadolinium-enhanced MRI of cartilage (dGEMRIC) protocol. Cartilage relaxation times were measured in both scans. Morphological sequences were assessed quantitatively using contrast ratios and qualitatively using a 4-point Likert scale. Student's t-test, Pearson's correlation (ρ) and Wilcoxon sign-rank test were used for statistical comparisons. Pre- and post-contrast T2 and T2* values were highly correlated (T2: acetabular: ρ = 0.76, femoral: ρ = 0.77; T2*: acetabular: ρ = 0.80, femoral: ρ = 0.72). Gadolinium enhanced contrasts between cartilage and joint fluid in DESS and T1 VIBE according to the qualitative (p = 0.01) and quantitative (p < 0.001) analysis. The delineation of acetabular and femoral cartilage and the labrum predominantly improved with gadolinium. Gadolinium showed no relevant influence on T2 or T2* relaxation times and improved morphological image quality at 7 T. Therefore, morphological and quantitative sequences including dGEMRIC can be conducted in a one-stop-shop examination. (orig.)

  15. Morphological imaging and T2 and T2* mapping of hip cartilage at 7 Tesla MRI under the influence of intravenous gadolinium

    Energy Technology Data Exchange (ETDEWEB)

    Lazik-Palm, Andrea; Geis, Christina; Goebel, Juliane; Theysohn, Jens M. [University Hospital Essen, Department of Diagnostic and Interventional Radiology and Neuroradiology, Essen (Germany); Kraff, Oliver; Johst, Soeren [University of Duisburg-Essen, Erwin L. Hahn Institute for Magnetic Resonance Imaging, Essen (Germany); Ladd, Mark E. [University Hospital Essen, Department of Diagnostic and Interventional Radiology and Neuroradiology, Essen (Germany); University of Duisburg-Essen, Erwin L. Hahn Institute for Magnetic Resonance Imaging, Essen (Germany); German Cancer Research Center (DKFZ), Division of Medical Physics in Radiology, Heidelberg (Germany); Quick, Harald H. [University of Duisburg-Essen, Erwin L. Hahn Institute for Magnetic Resonance Imaging, Essen (Germany); University Hospital Essen, High-Field and Hybrid MR Imaging, Essen (Germany)

    2016-11-15

    To investigate the influence of intravenous gadolinium on cartilage T2 and T2* relaxation times and on morphological image quality at 7-T hip MRI. Hips of 11 healthy volunteers were examined at 7 T. Multi-echo sequences for T2 and T2* mapping, 3D T1 volumetric interpolated breath-hold examination (VIBE) and double-echo steady-state (DESS) sequences were acquired before and after intravenous application of gadolinium according to a delayed gadolinium-enhanced MRI of cartilage (dGEMRIC) protocol. Cartilage relaxation times were measured in both scans. Morphological sequences were assessed quantitatively using contrast ratios and qualitatively using a 4-point Likert scale. Student's t-test, Pearson's correlation (ρ) and Wilcoxon sign-rank test were used for statistical comparisons. Pre- and post-contrast T2 and T2* values were highly correlated (T2: acetabular: ρ = 0.76, femoral: ρ = 0.77; T2*: acetabular: ρ = 0.80, femoral: ρ = 0.72). Gadolinium enhanced contrasts between cartilage and joint fluid in DESS and T1 VIBE according to the qualitative (p = 0.01) and quantitative (p < 0.001) analysis. The delineation of acetabular and femoral cartilage and the labrum predominantly improved with gadolinium. Gadolinium showed no relevant influence on T2 or T2* relaxation times and improved morphological image quality at 7 T. Therefore, morphological and quantitative sequences including dGEMRIC can be conducted in a one-stop-shop examination. (orig.)

  16. Substitution of the soluble boron reactivity control system of a pressurized water reactor by gadolinium burnable poisons

    International Nuclear Information System (INIS)

    Galperin, A.; Segev, M.; Radkowsky, A.

    1986-01-01

    The results are presented of a research project that is aimed at designing a gadolinium burnable poison (BP) system for complete reactivity control of a pressurized water reactor (PWR) core during the ''equilibrium'' cycle, resulting in the elimination of the soluble boron system, which represents a considerable saving in both capital and operating costs. A flat and strong negative moderator temperature coefficient is assured for a poison-free moderator. The design analysis of a core, heavily loaded with gadolinium BP rods, was based on a BGUCORE neutronic package and cluster model of a fuel assembly. The project objective was achieved by a novel lumped BP rod, designed as an annulus of gadolinium, clad by zirconium, and inserted into vacant guide thimbles of fresh-fuel assemblies. Specific combinations were found for the inner/outer radii of the poison ring, gadolinium densities, and number of rods per assembly, resulting in an almost flat criticality curve during the cycle. A reactivity swing of ≅1% ΔK can be easily controlled by an existing system of control rods. Comparison of the fuel cycle length of a gadolinium-controlled core with that of the reference, soluble, boron-controlled core indicated that there is no penalty due to residual poison at end of life. Unique guidelines for the fuel loading strategy were applied to find a practical fuel-shuffling scheme by which the design and operational constraints of a typical PWR core of current design were satisfied. Several problems should be solved for a practical implementation of the presented design relative to operational and safety requirements of the existing control rod system. Adequate movement of the regulating rods should be determined and shutdown margins of the safety rods should be ascertained. Final judgment of the feasibility of the concept may be made following the solution of these and other regulatory-related issues

  17. Mammary-Specific Ablation of the Calcium-Sensing Receptor During Lactation Alters Maternal Calcium Metabolism, Milk Calcium Transport, and Neonatal Calcium Accrual

    Science.gov (United States)

    Mamillapalli, Ramanaiah; VanHouten, Joshua; Dann, Pamela; Bikle, Daniel; Chang, Wenhan; Brown, Edward

    2013-01-01

    To meet the demands for milk calcium, the lactating mother adjusts systemic calcium and bone metabolism by increasing dietary calcium intake, increasing bone resorption, and reducing renal calcium excretion. As part of this adaptation, the lactating mammary gland secretes PTHrP into the maternal circulation to increase bone turnover and mobilize skeletal calcium stores. Previous data have suggested that, during lactation, the breast relies on the calcium-sensing receptor (CaSR) to coordinate PTHrP secretion and milk calcium transport with calcium availability. To test this idea genetically, we bred BLG-Cre mice with CaSR-floxed mice to ablate the CaSR specifically from mammary epithelial cells only at the onset of lactation (CaSR-cKO mice). Loss of the CaSR in the lactating mammary gland did not disrupt alveolar differentiation or milk production. However, it did increase the secretion of PTHrP into milk and decreased the transport of calcium from the circulation into milk. CaSR-cKO mice did not show accelerated bone resorption, but they did have a decrease in bone formation. Loss of the mammary gland CaSR resulted in hypercalcemia, decreased PTH secretion, and increased renal calcium excretion in lactating mothers. Finally, loss of the mammary gland CaSR resulted in decreased calcium accrual by suckling neonates, likely due to the combination of increased milk PTHrP and decreased milk calcium. These results demonstrate that the mammary gland CaSR coordinates maternal bone and calcium metabolism, calcium transport into milk, and neonatal calcium accrual during lactation. PMID:23782944

  18. Separation and purification of gadolinium and others rare earths, and yttrium

    International Nuclear Information System (INIS)

    Awwal, M.A.; Filgueiras, S.A.C.

    1988-01-01

    The experimental works in laboratories for developing a solvent extraction process with the purpose of gadolinium separation and purification, and secondarily samarium, europium, lanthanum and yttrium are described. Using as solvent di-2-ethylhexylphosphoric acid (DEHPA) a preliminary flow chart for separation for these elements are developed. (author)

  19. Hydrothermal synthesis and characterization of polycrystalline gadolinium aluminum perovskite (GdAlO3, GAP

    Directory of Open Access Journals (Sweden)

    N. Girish H.

    2015-06-01

    Full Text Available Gadolinium aluminum perovskite (GdAlO3, GAP is a promising high temperature ceramic material, known for its wide applications in phosphors. Polycrystalline gadolinium aluminum perovskites were synthesized using a precursor of co-precipitate gel of GdAlO3 by employing hydrothermal supercritical fluid technique under pressure and temperature ranging from 150 to 200 MPa and 600 to 700 °C, respectively. The resulted products of GAP were studied using the characterization techniques, such as powder X-ray diffraction analysis (XRD, infrared spectroscopy (IR, scanning electron microscopy (SEM and energy dispersive analysis of X-ray (EDX. The X-ray diffraction pattern matched well with the reported orthorhombic GAP pattern (JCPDS-46-0395.

  20. Detection of brain metastasis. Comparison of Turbo-FLAIR imaging, T2-weighted imaging and double-dose gadolinium-enhanced MR imaging

    International Nuclear Information System (INIS)

    Okubo, Toshiyuki; Hayashi, Naoto; Shirouzu, Ichiro; Abe, Osamu; Ohtomo, Kuni; Sasaki, Yasuhito; Aoki, Shigeki; Wada, Akihiko

    1998-01-01

    The purpose of this study was to compare Turbo-FLAIR imaging, T 2 -weighted imaging, and double-dose gadolinium-enhanced MR imaging in the detection of brain metastasis. Using the three sequences, 20 consecutive patients with brain metastases were prospectively studied with a 1.5-Tesla system. Three independent, blinded readers assessed the images for the presence, size, number, and location of metastatic lesions. In the detection of large lesions (>0.5 cm), Turbo-FLAIR imaging (38/48, 79%) was not significantly different from gadolinium-enhanced imaging (42/48, 88%) (p=0.273). T 2 -weighted imaging (31/48, 65%), however, was inferior to gadolinium-enhanced imaging (p<0.05). There was no difference between Turbo-FLAIR imaging and gadolinium-enhanced imaging in the accuracy of detecting solitary brain metastasis (4/4, 100%). In conclusion, Turbo-FLAIR imaging is a useful, noninvasive screening modality for brain metastasis. Its use may lead to cost savings in the diagnosis of brain metastases and may impact positively the cost-effectiveness of treatment. (author)

  1. Role of an ionic liquid, 1-butyl-3-methylimidazolium 2-(2-methoxyethoxy)ethyl sulfate in extraction studies of gadolinium oxide

    Energy Technology Data Exchange (ETDEWEB)

    Sen, Kamalika [Calcutta Univ., Kolkata (India). Dept. of Chemistry; Wolterbeek, H.T. [Technical Univ. Delft (NL). Section RIH (Radiation and Isotopes in Health)

    2012-07-01

    The room temperature ionic liquid (RTIL), 1-butyl-3-methylimidazolium 2-(2-methoxyethoxy)ethyl sulfate was studied for its extraction behavior for {sup 159}Gd in an environmentally benign liquid-liquid extraction system. The gadolinium oxide when dissolved in nitric acid and extracted in an RTIL/dextran biphasic system, was found to get completely extracted in the IL phase. The otherwise difficult to dissolve gadolinium oxide was found to have some solubility in the IL studied. Biphasic systems consisting of IL/dextran and certain IL/salt were studied for the extraction behavior of Gd{sub 2}O{sub 3} dissolved in the above RTIL. A similar experiment was also done with acid-dissolved gadolinium oxide for comparison. (orig.)

  2. Impact of Impaired Renal Function on Gadolinium Retention After Administration of Gadolinium-Based Contrast Agents in a Mouse Model.

    Science.gov (United States)

    Kartamihardja, A Adhipatria P; Nakajima, Takahito; Kameo, Satomi; Koyama, Hiroshi; Tsushima, Yoshito

    2016-10-01

    The aim of this study was to investigate the impact of impaired renal function on gadolinium (Gd) retention in various organs after Gd-based contrast agent injection. After local animal care and review committee approval, 23 normal mice and 26 with renal failure were divided into 4 treatment groups (Gd-DTPA-BMA, 5 mmol/kg; Gd-DOTA, 5 mmol/kg; GdCl3, 0.02 mmol/kg; and saline, 250 μL). Each agent was intravenously administered on weekdays for 4 weeks. Samples were collected on days 3 (short-term) and 45 (long-term) after the last injection. Gadolinium concentrations were quantified by inductively coupled plasma-mass spectrometry. Three mice with renal failure and 2 normal mice in the GdCl3 group and 1 mouse with renal failure in the Gd-DTPA-BMA group died. In the Gd-DTPA-BMA group, impaired renal function increased short-term Gd retention in the liver, bone, spleen, skin, and kidney (P DTPA-BMA showed higher Gd retention than Gd-DOTA. Although Gd retention in the Gd-DOTA group was generally low, impaired renal function increased only long-term hepatic Gd retention. Hepatic and splenic Gd retentions were significantly higher than other organs' Gd retention in the GdCl3 group (P DTPA-BMA administration, long-term Gd retention for Gd-based contrast agents was almost unaffected by renal function, suggesting that the chemical structures of retained Gd may not be consistent and some Gd is slowly eliminated after initially being retained.

  3. International comparison calculations for a BWR lattice with adjacent gadolinium pins

    International Nuclear Information System (INIS)

    Maeder, C.; Wydler, P.

    1984-09-01

    The results of burnup calculations for a simplified BWR fuel element with two adjacent gadolinium rods are presented and discussed. Ten complete solutions were contributed by Denmark, France, Italy (3), Japan (3), Switzerland and the UK. Partial results obtained from Poland and the USA are included in an Appendix. (Auth.)

  4. Apparent molar volumes and compressibilities of lanthanum, gadolinium and lutetium trifluoromethanesulfonates in dimethylsulfoxide

    International Nuclear Information System (INIS)

    Warmińska, Dorota; Wawer, Jarosław

    2012-01-01

    Highlights: ► Sequence of volumes and compressibilities of Ln 3+ ions in DMSO is: La 3+ > Gd 3+ 3+ . ► Sequence of the partial molar volumes do not change with temperature. ► These results are the consequence of nature of the ion–solvent bonding. - Abstract: Temperature dependencies of the densities of dimethylsulfoxide solutions of lanthanum, gadolinium and lutetium trifluoromethanesulfonates have been determined over a wide range of concentrations. The apparent molar volumes and partial molar volumes of the salts at infinite dilution, as well as the expansibilities of the salts, have been calculated from density data. Additionally, the apparent molar isentropic compressibilities of lanthanum, gadolinium and lutetium trifluoromethanesulfonates have been calculated from sound velocity data at 298.15 K. The data obtained have been interpreted in terms of ion−solvent interactions.

  5. Applying Amide Proton Transfer MR Imaging to Hybrid Brain PET/MR: Concordance with Gadolinium Enhancement and Added Value to [18F]FDG PET.

    Science.gov (United States)

    Sun, Hongzan; Xin, Jun; Zhou, Jinyuan; Lu, Zaiming; Guo, Qiyong

    2018-06-01

    The purpose of this study is to evaluate the diagnostic concordance and metric correlations of amide proton transfer (APT) imaging with gadolinium-enhanced magnetic resonance imaging (MRI) and 2-deoxy-2-[ 18 F-]fluoro-D-glucose ([ 18 F]FDG) positron emission tomography (PET), using hybrid brain PET/MRI. Twenty-one subjects underwent brain gadolinium-enhanced [ 18 F]FDG PET/MRI prospectively. Imaging accuracy was compared between unenhanced MRI, MRI with enhancement, APT-weighted (APTW) images, and PET based on six diagnostic criteria. Among tumors, the McNemar test was further used for concordance assessment between gadolinium-enhanced imaging, APT imaging, and [ 18 F]FDG PET. As well, the relation of metrics between APT imaging and PET was analyzed by the Pearson correlation analysis. APT imaging and gadolinium-enhanced MRI showed superior and similar diagnostic accuracy. APTW signal intensity and gadolinium enhancement were concordant in 19 tumors (100 %), while high [ 18 F]FDG avidity was shown in only 12 (63.2 %). For the metrics from APT imaging and PET, there was significant correlation for 13 hypermetabolic tumors (P PET in the evaluation of tumor metabolic activity during brain PET/MR studies.

  6. [Calcium suppletion for patients who use gastric acid inhibitors: calcium citrate or calcium carbonate?].

    NARCIS (Netherlands)

    Jonge, H.J. de; Gans, R.O.; Huls, G.A.

    2012-01-01

    Various calcium supplements are available for patients who have an indication for calcium suppletion. American guidelines and UpToDate recommend prescribing calcium citrate to patients who use antacids The rationale for this advice is that water-insoluble calcium carbonate needs acid for adequate

  7. Impact of newly-measured gadolinium cross sections on BWR fuel rod reaction rate distributions

    Energy Technology Data Exchange (ETDEWEB)

    Jatuff, F.; Perret, G.; Murphy, M.; Grimm, P.; Seiler, R. [Paul Scherrer Institute, CH-5232 Villigen PSI (Switzerland); Chawla, R. [Paul Scherrer Institute, CH-5232 Villigen PSI (Switzerland); Ecole Polytechnique Federal de Lausanne, CH-1015 Lausanne (Switzerland)

    2008-07-01

    Recent measurements of capture and total cross sections performed at the Rensselaer Polytechnic Institute in the USA confirmed many of the gadolinium thermal and resonant neutron cross section parameters within uncertainties, but they also showed up important discrepancies well out of uncertainties, such as an approx11% overestimation of the {sup 157}Gd thermal capture cross section in ENDF/B-VI and -VII with respect to the newly measured data. In this work, the impact of the newly measured gadolinium cross sections on BWR reactor physics parameters has been preliminarily evaluated. The comparisons of rod-by-rod fission rate and modified conversion ratio predictions with selected cold critical experiments at the PROTEUS reactor in Switzerland show the potential to resolve long-term unexplained discrepancies. (authors)

  8. Silica nanoparticles containing 159-Gadolinium as potential system for cancer treatment

    International Nuclear Information System (INIS)

    Oliveira, Andre Felipe de; Ferreira, Tiago Hilario; Sousa, Edesia Martins Barros de; Lacerda, Marco Aurelio

    2013-01-01

    Ordered silica nanoparticles are compounds highly organized which have very interesting textural characteristics, such as high thermal stability, well defined pore size, narrow size distribution and high area surface. Among the various types of nano materials ordered, the SBA-16 have a meso structure that can be considered very interesting due to the fact of the arrangement of mesoporous (tri dimensional as a cage) and spherical morphology, which make it in a promising material for a range of bioapplications such as incorporation of drugs and radioisotopes. In this study Gadodiamide® (Omniscan-General Electric Healthcare Company), a frequently non-ionic gadolinium complex contrasting used in MRI's was incorporated in the silica matrix SBA-16 as a carrier. From this gadolinium it is possible to obtain the isotope 159 Gd by neutron irradiation, wherein the isotope 158 Gd captures a neutron and becomes 159 Gd [ 15 '8Gd(n,c) 1 '5 9 Gd]. The 159 Gd is a beta (endpoint energy of 970.6 keV) and gamma (main energy: 363.54 keV) emitter with a half-life of 18.59 hours. These characteristics are similar to that of other isotopes already used in nuclear medicine such as 90 Y. In this work, the 158 Gd incorporated in the Gd-silica was activated by the neutron flux generated by the cyclotron located in the Centro de Desenvolvimento da Tecnologia Nuclear (CDTN) during the production of the 18 FDG. Atomic emission spectroscopy (ICP-AES) and infrared spectroscopy (FTIR) were used to confirm the presence of the gadolinium complex in the silica matrix. The antitumor activity of the complex after the irradiation was evaluated through cytotoxicity assay with T98 cell lines derived from a human glioblastoma multiform tumor. (author)

  9. Breakthrough reactions of iodinated and gadolinium contrast media after oral steroid premedication protocol.

    Science.gov (United States)

    Jingu, Akiko; Fukuda, Junya; Taketomi-Takahashi, Ayako; Tsushima, Yoshito

    2014-10-06

    Adverse reactions to iodinated and gadolinium contrast media are an important clinical issue. Although some guidelines have proposed oral steroid premedication protocols to prevent adverse reactions, some patients may have reactions to contrast media in spite of premedication (breakthrough reaction; BTR).The purpose of this study was to assess the frequency, type and severity of BTR when following an oral steroid premedication protocol. All iodinated and gadolinium contrast-enhanced radiologic examinations between August 2011 and February 2013 for which the premedication protocol was applied in our institution were assessed for BTRs. The protocol was applied to a total of 252 examinations (153 patients, ages 15-87 years; 63 males, 90 females). Of these, 152 were for prior acute adverse reactions to contrast media, 85 were for a history of bronchial asthma, and 15 were for other reasons. There were 198 contrast enhanced CTs and 54 contrast enhanced MRIs. There were nine BTR (4.5%) for iodinated contrast media, and only one BTR (1.9%) for gadolinium contrast media: eight were mild and one was moderate. No patient who had a mild index reaction (IR) had a severe BTR. Incidence of BTRs when following the premedication protocol was low. This study by no means proves the efficacy of premedication, but provides some support for following a premedication protocol to improve safety of contrast-enhanced examinations when prior adverse reactions are mild, or when there is a history of asthma.

  10. Breakthrough reactions of iodinated and gadolinium contrast media after oral steroid premedication protocol

    International Nuclear Information System (INIS)

    Jingu, Akiko; Fukuda, Junya; Taketomi-Takahashi, Ayako; Tsushima, Yoshito

    2014-01-01

    Adverse reactions to iodinated and gadolinium contrast media are an important clinical issue. Although some guidelines have proposed oral steroid premedication protocols to prevent adverse reactions, some patients may have reactions to contrast media in spite of premedication (breakthrough reaction; BTR). The purpose of this study was to assess the frequency, type and severity of BTR when following an oral steroid premedication protocol. All iodinated and gadolinium contrast-enhanced radiologic examinations between August 2011 and February 2013 for which the premedication protocol was applied in our institution were assessed for BTRs. The protocol was applied to a total of 252 examinations (153 patients, ages 15–87 years; 63 males, 90 females). Of these, 152 were for prior acute adverse reactions to contrast media, 85 were for a history of bronchial asthma, and 15 were for other reasons. There were 198 contrast enhanced CTs and 54 contrast enhanced MRIs. There were nine BTR (4.5%) for iodinated contrast media, and only one BTR (1.9%) for gadolinium contrast media: eight were mild and one was moderate. No patient who had a mild index reaction (IR) had a severe BTR. Incidence of BTRs when following the premedication protocol was low. This study by no means proves the efficacy of premedication, but provides some support for following a premedication protocol to improve safety of contrast-enhanced examinations when prior adverse reactions are mild, or when there is a history of asthma

  11. Vessel diameter measurements in gadolinium contrast-enhanced three-dimensional MRA of peripheral arteries

    NARCIS (Netherlands)

    Westenberg, J.J.M.; Geest, van der R.J.; Wasser, M.N.J.M.; Linden, van der E.L.; Walsum, van T.; Assen, van H.C.; Roos, de A.; Vanderschoot, J.; Reiber, J.H.C.

    2000-01-01

    In this study, the possibilities for quantification of vessel diameters of peripheral arteries in gadolinium contrast-enhanced magnetic resonance angiography (Gd CE MRA) were evaluated. Absolute vessel diameter measurements were assessed objectively and semi-automatically in maximum intensity

  12. Extracellular gadolinium contrast agents: Differences in stability

    International Nuclear Information System (INIS)

    Morcos, S.K.

    2008-01-01

    Extracellular gadolinium contrast agents (Gd-CA) are either linear or macrocyclic chelates available as ionic or non-ionic preparations. The molecular structure whether cyclic or linear and ionicity determines the stability of Gd-CA. Linear chelates are flexible open chains which do not offer a strong binding to Gd 3+ . In contrast, the macrocyclic chelates offer a strong binding to Gd 3+ by the virtue of being preorganized rigid rings of almost optimal size to cage the gadolinium atom. Non-ionic preparations are also less stable in comparison to the ionic ones as the binding between Gd 3+ with the negatively charged carboxyl groups is stronger in comparison to that with amides or alcohol in the non-ionic preparations. According to stability constants and kinetic measurements, the most stable Gd-CM is the ionic-macrocyclic chelate Gd-DOTA and the least stable agents are the non-ionic linear chelates gadodiamide and gadoversetamide. In vivo data confirmed the low stability of non-ionic linear chelates but no significant difference was observed amongst the macrocyclic agents whether ionic (Gd-DOTA) or non-ionic such as Gd-HP-DO3A and Gd-BT-DO3A. The stability of Gd-CA seems to be an important factor in the pathogenesis of the serious complication of nephrogenic systemic fibrosis. Gd-CA of low stability are likely to undergo transmetallation and release free Gd ions that deposit in tissue and attract circulating fibrocytes to initiate the process of fibrosis. No cases of NSF have been observed so far after the exclusive use of the stable macrocyclic Gd-CA

  13. Gadolinium burnable absorber optimization by the method of conjugate gradients

    International Nuclear Information System (INIS)

    Drumm, C.R.; Lee, J.C.

    1987-01-01

    The optimal axial distribution of gadolinium burnable poison in a pressurized water reactor is determined to yield an improved power distribution. The optimization scheme is based on Pontryagin's maximum principle, with the objective function accounting for a target power distribution. The conjugate gradients optimization method is used to solve the resulting Euler-Lagrange equations iteratively, efficiently handling the high degree of nonlinearity of the problem

  14. Effect of Cu2+ substitution on the structural, magnetic and electrical properties of gadolinium orthoferrite

    Science.gov (United States)

    Sai Vandana, C.; Hemalatha Rudramadevi, B.

    2018-04-01

    The pure and copper (Cu) substituted Gadolinium orthoferrites, GdFeO3, GdCu0.1Fe0.9O3, GdCu0.2Fe0.8O3 and GdCu0.3Fe0.7O3 were synthesized by conventional solid state method. The structural, morphological, dielectric, magnetic and impedance properties of Cu substituted Gadolinium orthoferrites have been investigated. The crystallographic phase as well as the substitution of Cu2+ ions in the lattice of GdFeO3 is confirmed from the x-ray diffraction patterns. The Fourier transform infrared spectra exhibit two prominent fundamental absorption peaks at ∼417 cm‑1 and 545 cm‑1. These bands are related to inherent stretching vibrations of metals at octahedral and tetrahedral sites respectively. The coercivity (Hc) and saturation magnetization (Ms) of the synthesized samples at different temperatures were determined from the hysteresis plots. Higher coercive values, 598 Oe and 600 Oe were achieved in GdCu0.1Fe0.9O3 ferrites compared to 527 Oe and 360 Oe in pure GdFeO3 at room temperature (300 K) and low temperature (20 k) respectively. Dielectric dispersion has been observed for gadolinium ferrite samples with Maxwell–Wagner type interfacial polarization. The decrease of dielectric constant and dielectric loss tangent with an increase in frequency was observed. The conduction due to charge hopping between localized states was confirmed from AC conductivity measurements. The composition dependent cationic distributions estimated from XRD, magnetic and electrical studies are in good agreement with each other. The achieved results indicate that the substitution of Cu in gadolinium orthoferrite strongly influences the crystal structure, magnetic and electrical properties thereby making them suitable as multiple state memory devices, transducers, electronic field controlled ferromagnetic resonance devices and spintronic devices.

  15. Application of extracellular gadolinium-based MRI contrast agents and the risk of nephrogenic systemic fibrosis; Anwendung von extrazellulaeren gadoliniumhaltigen MR-Kontrastmitteln und Risiko der Nephrogenen Systemischen Fibrose

    Energy Technology Data Exchange (ETDEWEB)

    Heverhagen, J.T. [Univ. Hospital Bern (Switzerland). Inst. of Diagnostic, Interventional and Pediatric Radiology, Inselspital; Krombach, G.A. [Justus Liebig Univ. Hopsital Giessen (Germany). Diagnostic and Interventional Radiology; Gizewski, E. [Medical Univ. Innsbruck (Austria). Dept. of Neuroradiology

    2014-07-15

    Nephrogenic systemic fibrosis (NSF) is a serious, sometimes fatal disease. Findings in recent years have shown that a causal association between gadolinium containing contrast media and NSF is most likely. Therefore, the regulatory authorities have issued guidelines on the use of gadolinium-containing contrast media which have reduced the number of new cases of NSF to almost zero. However, it is for precisely this reason that the greatest care must still be taken to ensure that these guidelines are complied with. The most important factors are renal function, the quantity of gadolinium administered and coexisting diseases such as inflammation. All of these factors crucially influence the quantity of gadolinium released from the chelat in the body. This free gadolinium is thought to be the trigger for NSF. Other important factors are the stability of the gadolinium complex and furthermore the route of its elimination from the body. Partial elimination via the liver might be an additional protective mechanism. In conclusion, despite the NSF risk, contrast-enhanced MRI is a safe diagnostic procedure which can be used reliably and safely even in patients with severe renal failure, and does not necessarily have to be replaced by other methods.

  16. Extracellular gadolinium-based contrast media: An overview

    International Nuclear Information System (INIS)

    Bellin, Marie-France; Van Der Molen, Aart J.

    2008-01-01

    Increasing use is made of extracellular MRI contrast agents that alter the image contrast following intravenous administration; they predominantly shorten the T1 relaxation time of tissues. The degree and location of these changes provide substantial diagnostic information. However gadolinium-based contrast agents (Gd-CA) are not inert drugs. They may cause acute non-renal adverse reactions (e.g. anaphylactoid reactions), acute renal adverse reactions (e.g. contrast induced nephropathy), delayed adverse reactions (nephrogenic systemic fibrosis) and problems at the site of injection (e.g. local necrosis). This review describes the current status of Gd-CA, their mechanism of action, chemical structure, pharmacokinetics, dosage, elimination, nephrotoxicity and adverse events

  17. Extracellular gadolinium-based contrast media: An overview

    Energy Technology Data Exchange (ETDEWEB)

    Bellin, Marie-France [University Paris-Sud 11, Department of Radiology, University Hospital Paul-Brousse, AP-HP, 12, Avenue Paul Vaillant-Couturier, 94804 Villejuif Cedex (France)], E-mail: marie-france.bellin@pbr.aphp.fr; Van Der Molen, Aart J. [University Paris-Sud 11, Department of Radiology, University Hospital Paul-Brousse, AP-HP, 12, Avenue Paul Vaillant-Couturier, 94804 Villejuif Cedex (France)

    2008-05-15

    Increasing use is made of extracellular MRI contrast agents that alter the image contrast following intravenous administration; they predominantly shorten the T1 relaxation time of tissues. The degree and location of these changes provide substantial diagnostic information. However gadolinium-based contrast agents (Gd-CA) are not inert drugs. They may cause acute non-renal adverse reactions (e.g. anaphylactoid reactions), acute renal adverse reactions (e.g. contrast induced nephropathy), delayed adverse reactions (nephrogenic systemic fibrosis) and problems at the site of injection (e.g. local necrosis). This review describes the current status of Gd-CA, their mechanism of action, chemical structure, pharmacokinetics, dosage, elimination, nephrotoxicity and adverse events.

  18. Gadolinium-DTPA enhanced MRI of the brain

    International Nuclear Information System (INIS)

    Hosten, N.; Felix, R.

    1994-01-01

    The text reviews MRI findings in a variety of cerebral diseases. Advantages of Gadolinium-DTPA (Gd-DTPA) enhanced MRI over plain MRI and enhanced CT are discussed. Enhanced MRI is far superior to enhanced CT in the detection of meningeal tumor spread, meningeal inflammation, inflammatory lesions of the optic nerve, brain lesions in multiple sclerosis and infarction. Enhanced MRI is today the most sensitive diagnostic tool in hypophaseal adenomas. Also enhancement of gliomas is detected by MRI with higher sensitivity than by CT. Use Gd-DTPA allow to separate of vital tumor tissue from necrosis and edema, improve delineation of tumor extension and improve detection of lesions localized in gray matter

  19. 21 CFR 172.330 - Calcium pantothenate, calcium chloride double salt.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Calcium pantothenate, calcium chloride double salt... FOOD FOR HUMAN CONSUMPTION Special Dietary and Nutritional Additives § 172.330 Calcium pantothenate, calcium chloride double salt. The food additive calcium chloride double salt of calcium pantothenate may...

  20. Brain MR post-gadolinium contrast in multiple sclerosis: the role of magnetization transfer and image subtraction in detecting more enhancing lesions

    Energy Technology Data Exchange (ETDEWEB)

    Gavra, M.M.; Gouliamos, A.D.; Vlahos, L.J. [Department of Radiology, ' ' Aretaieion' ' Hospital,University of Athens Medical School, Athens (Greece); Voumvourakis, C.; Sfagos, C. [Department of Neurology, ' ' Eginiteion' ' Hospital, University of Athens Medical School, Athens (Greece)

    2004-03-01

    Our purpose was to evaluate the role of magnetization transfer and image subtraction in detecting more enhancing lesions in brain MR imaging of patients with multiple sclerosis (MS). Thirty-one MS patients underwent MR imaging of the brain with T1-weighted spin echo sequences without and with magnetization transfer (MT) using a 1.5 T imager. Both sequences were acquired before and after intravenous injection of a paramagnetic contrast agent. Subtraction images in T1-weighted sequences were obtained by subtracting the pre-contrast images from the post-contrast ones. A significant difference was found between the numbers of enhanced areas in post-gadolinium T1-weighted images without and with MT (p=0.020). The post-gadolinium T1-weighted images with MT allowed the detection of an increased (13) number of enhancing lesions compared with post-gadolinium T1-weighted images without MT. A significant difference was also found between the numbers of enhanced areas in post-gadolinium T1-weighted images without MT and subtraction images without MT (p=0.020). The subtraction images without MT allowed the detection of an increased (10) number of enhancing lesions compared with post-gadolinium T1-weighted images without MT. Magnetization transfer contrast and subtraction techniques appear to be the simplest and least time-consuming applications to improve the conspicuity and detection of contrast-enhancing lesions in patients with MS. (orig.)

  1. Brain MR post-gadolinium contrast in multiple sclerosis: the role of magnetization transfer and image subtraction in detecting more enhancing lesions

    International Nuclear Information System (INIS)

    Gavra, M.M.; Gouliamos, A.D.; Vlahos, L.J.; Voumvourakis, C.; Sfagos, C.

    2004-01-01

    Our purpose was to evaluate the role of magnetization transfer and image subtraction in detecting more enhancing lesions in brain MR imaging of patients with multiple sclerosis (MS). Thirty-one MS patients underwent MR imaging of the brain with T1-weighted spin echo sequences without and with magnetization transfer (MT) using a 1.5 T imager. Both sequences were acquired before and after intravenous injection of a paramagnetic contrast agent. Subtraction images in T1-weighted sequences were obtained by subtracting the pre-contrast images from the post-contrast ones. A significant difference was found between the numbers of enhanced areas in post-gadolinium T1-weighted images without and with MT (p=0.020). The post-gadolinium T1-weighted images with MT allowed the detection of an increased (13) number of enhancing lesions compared with post-gadolinium T1-weighted images without MT. A significant difference was also found between the numbers of enhanced areas in post-gadolinium T1-weighted images without MT and subtraction images without MT (p=0.020). The subtraction images without MT allowed the detection of an increased (10) number of enhancing lesions compared with post-gadolinium T1-weighted images without MT. Magnetization transfer contrast and subtraction techniques appear to be the simplest and least time-consuming applications to improve the conspicuity and detection of contrast-enhancing lesions in patients with MS. (orig.)

  2. Homogeneous dispersion of gadolinium oxide nanoparticles into a non-aqueous-based polymer by two surface treatments

    Energy Technology Data Exchange (ETDEWEB)

    Samuel, Jorice, E-mail: jorice.samuel@gmail.com [AREVA T and D UK Ltd, AREVA T and D Research and Technology Centre (United Kingdom); Raccurt, Olivier [NanoChemistry and Nanosafety Laboratory (DRT/LITEN/DTNM/LCSN), CEA Grenoble, Department of NanoMaterials (France); Mancini, Cedric; Dujardin, Christophe; Amans, David; Ledoux, Gilles [Universite de Lyon, Laboratoire de Physico Chimie des Materiaux Luminescents (LPCML) (France); Poncelet, Olivier [NanoChemistry and Nanosafety Laboratory (DRT/LITEN/DTNM/LCSN), CEA Grenoble, Department of NanoMaterials (France); Tillement, Olivier [Universite de Lyon, Laboratoire de Physico Chimie des Materiaux Luminescents (LPCML) (France)

    2011-06-15

    Gadolinium oxide nanoparticles are more and more used. They can notably provide interesting fluorescence properties. Herein they are incorporated into a non-aqueous-based polymer, the poly(methyl methacrylate). Their dispersion within the polymer matrix is the key to improve the composite properties. As-received gadolinium oxide nanopowders cannot be homogeneously dispersed in such a polymer matrix. Two surface treatments are, therefore, detailed and compared to achieve a good stability of the nanoparticles in a non-aqueous solvent such as the 2-butanone. Then, once the liquid suspensions have been stabilized, they are used to prepare nanocomposites with homogeneous particles dispersion. The two approaches proposed are an hybrid approach based on the growth of a silica shell around the gadolinium oxide nanoparticles, and followed by a suitable silane functionalization; and a non-hybrid approach based on the use of surfactants. The surface treatments and formulations involved in both methods are detailed, adjusted and compared. Thanks to optical methods and in particular to the use of a 'home made' confocal microscope, the dispersion homogeneity within the polymer can be assessed. Both methods provide promising and conclusive results.

  3. Gadolinium-Hematoporphyrin: new potential MRI contrast agent for detection of breast cancer cell line (MCF-7

    Directory of Open Access Journals (Sweden)

    D Shahbazi Gahrouei

    2005-09-01

    Full Text Available Background: Gadolinium-porphyrins have been synthesized and are currently being investigated as magnetic resonance imaging (MRI contrast agents. This study aimed to synthesize Gd-hematoporphyrin and applicate it for in vitro detection of breast cancer cell line (MCF-7. Methods: The naturally occurring porphyrin (hematoporphyrin was inserted with gadolinium (III nitrate hexahydrate to yield Gd-H. T1 relaxation times and signal enhancement of the contrast agents were presented, and the results were compared. UV spectrophotometer measured the attachment of Gd to the cell membrane of MCF-7. Results: Most of gadolinium chloride (GdCl3 was found in the washing solution, indicate that it didn`t fixed to the breast cell membranes during incubation. Gd-DTPA showed some uptake into the MCF-7 cell membranes with incubation, however, its uptake was significantly lower than Gd-H. Conclusion: Good cell memberan uptake of Gd-porphyrin is comparable to controls, indicating selective delivery it to the breast cell line and considerable potency in diagnostic MR imaging for detection of breast cancer. Key Words: Porphyrin, Contrast agent, MRI, Hematoporphyrin, Breast cancer cell (MCF-7

  4. Determination of percent calcium carbonate in calcium chromate

    International Nuclear Information System (INIS)

    Middleton, H.W.

    1979-01-01

    The precision, accuracy and reliability of the macro-combustion method is superior to the Knorr alkalimetric method, and it is faster. It also significantly reduces the calcium chromate waste accrual problem. The macro-combustion method has been adopted as the official method for determination of percent calcium carbonate in thermal battery grade anhydrous calcium chromate and percent calcium carbonate in quicklime used in the production of calcium chromate. The apparatus and procedure can be used to measure the percent carbonate in inorganic materials other than calcium chromate. With simple modifications in the basic apparatus and procedure, the percent carbon and hydrogen can be measured in many organic material, including polymers and polymeric formulations. 5 figures, 5 tables

  5. About thermo-electric properties of bismuth telluride doped by gadolinium

    International Nuclear Information System (INIS)

    Akperov, M.M.; Ismailov, Sh.S.; Shukyurova, A.A.

    2004-01-01

    Results of study of the Gd impurities effect on the bismuth telluride thermo-electric properties are presented. The experiment was carried out within the temperature range T=300-700 K. It is determined, that at temperature increase the energy level is appreciably closing up to bismuth telluride forbidden zone which makes up 0.16-0.24 eV. Such anomalous energy properties of gadolinium in telluride affect on material thermoelectric properties

  6. Hyperfine coupling in gadolinium-praseodymium alloys by specific heat measurements

    International Nuclear Information System (INIS)

    Michel, J.

    1969-01-01

    We have studied the hyperfine coupling in gadolinium-praseodymium alloys by specific heat measurements down to 0.3 K. In the first part we describe the apparatus used to perform our measurements. The second part is devoted to some theoretical considerations. We have studied in detail the case of praseodymium which is an exception in the rare earth series. The third part shows the results we have obtained. (author) [fr

  7. Atypical Distribution of Late Gadolinium Enhancement of the Left Ventricle on Cardiac Magnetic Resonance in Classical Anderson-Fabry Disease

    OpenAIRE

    Kasuya, Shusuke; Suzuki, Masayo; Inaoka, Tsutomu; Odashima, Masayuki; Nakatsuka, Tomoya; Ishikawa, Rumiko; Tokuyama, Wataru; Terada, Hitoshi

    2016-01-01

    Anderson-Fabry disease (AFD) is an X-linked lysosomal storage disorder caused by a deficiency of alpha-galactosidase A. Approximately 50% of patients with AFD may have cardiac involvement. Gadolinium-enhanced cardiac magnetic resonance (CMR) is useful for the diagnosis of cardiac involvement of AFD by recognizing typical late gadolinium enhancement (LGE) patterns. We report a 48-year-old man with cardiac involvement in classical AFD, showing atypical distribution of the LGE at the mid-lateral...

  8. Study of points defects produced by irradiation of monocrystalline nickel and polycrystalline gadolinium

    International Nuclear Information System (INIS)

    Cope, R.

    1969-07-01

    The work described in this thesis falls into two parts: the first comprises a study of magnetocrystalline nickel by resistivity measurements; the second is a description of resistivity and magnetic after effect measurements on an h.c.p. ferromagnetic crystal other than cobalt, namely gadolinium. For the first part we have demonstrated the existence of a small but definite orientation dependence in the creation of point defects by electron irradiation (20 deg. K) of a nickel single crystal. In particular, the effect is manifested in the form of the stage I C , II and III in the resistivity recovery. In the second part an important result has emerged: namely that there is no magnetic after effect phenomenon in a neutron irradiated (27 deg. K) ferromagnetic metal. Several considerations are discussed by way of a preliminary interpretation of this important difference between gadolinium and cobalt. (author) [fr

  9. Imaging of cauda equina edema in lumbar canal stenosis by using gadolinium-enhanced MR imaging: experimental constriction injury.

    Science.gov (United States)

    Kobayashi, S; Uchida, K; Takeno, K; Baba, H; Suzuki, Y; Hayakawa, K; Yoshizawa, H

    2006-02-01

    It has been reported that disturbance of blood flow arising from circumferential compression of the cauda equina by surrounding tissue plays a major role in the appearance of neurogenic intermittent claudication (NIC) associated with lumbar spinal canal stenosis (LSCS). We created a model of LSCS to clarify the mechanism of enhancement within the cauda equina on gadolinium-enhanced MR images from patients with LSCS. In 20 dogs, a lumbar laminectomy was performed by applying circumferential constriction to the cauda equina by using a silicon tube, to produce 30% stenosis of the circumferential diameter of the dural tube. After 1 and 3 weeks, gadolinium and Evans blue albumin were injected intravenously at the same time. The sections were used to investigate the status of the blood-nerve barrier function under a fluorescence microscope and we compared gadolinium-enhanced MR images with Evans blue albumin distribution in the nerve. The other sections were used for light and transmission electron microscopic study. In this model, histologic examination showed congestion and dilation in many of the intraradicular veins, as well as inflammatory cell infiltration. The intraradicular edema caused by venous congestion and Wallerian degeneration can also occur at sites that are not subject to mechanical compression. Enhanced MR imaging showed enhancement of the cauda equina at the stenosed region, demonstrating the presence of edema. Gadolinium-enhanced MR imaging may be a useful tool for the diagnosis of microcirculatory disorders of the cauda equina associated with LSCS.

  10. Gadolinium enhancement of cerebrospinal fluid in a patient with renal failure

    International Nuclear Information System (INIS)

    Erbay, S.H.; Bhadelia, R.A.

    2001-01-01

    Gadolinium based MRI contrast agents are considered very safe due to their well known pharmacologic properties and elimination mechanisms. In this paper, we present a unique case in whom transient enhancement of CSF with contrast is seen. Severe renal failure is demonstrated to be responsible for this finding. The diagnostic criteria for everyday clinical setting and possible clinical implications are discussed. (orig.)

  11. Highly-crystalline ultrathin gadolinium doped and carbon-coated Li4Ti5O12 nanosheets for enhanced lithium storage

    Science.gov (United States)

    Xu, G. B.; Yang, L. W.; Wei, X. L.; Ding, J. W.; Zhong, J. X.; Chu, P. K.

    2015-11-01

    Highly-crystalline gadolinium doped and carbon-coated ultrathin Li4Ti5O12 (LTO) nanosheets (denoted as LTO-Gd-C) as an anode material for Li-ion batteries (LIBs) are synthesized on large scale by controlling the amount of carbon precursor in the topotactic transformation of layered ultrathin Li1.81H0.19Ti2O5·xH2O (H-LTO) nanosheets at 700 °C. The characterizations of structure and morphology reveal that the gadolinium doped and carbon-coated ultrathin LTO nanosheets have high crystallinity with a thickness of about 10 nm. Gadolinium doping allows the spinel LTO products to be stabilized, thereby preserving the precursor's sheet morphology and single crystal structure. Carbon encapsulation serves dual functions by restraining crystal growth of the LTO primary nanoparticles in the LTO-Gd-C nanosheets and decreasing the external electron transport resistance. Owing to the synergistic effects rendered by ultrathin nanosheets with high crystallinity, gadolinium doping and carbon coating, the developed ultrathin LTO nanosheets possess excellent specific capacity, cycling performance, and rate capability compared with reference materials, when evaluated as an anode material for lithium ion batteries (LIBs). The simple and effective strategy encompassing nanoscale morphological engineering, surface modification, and doping improves the performance of LTO-based anode materials for high energy density and high power LIBs applied in large scale energy storage.

  12. The trial of obtaining a high-grade gadolinium concentrate using the fractional precipitation together with the ion exchange

    International Nuclear Information System (INIS)

    Ozga, W.; Soltysiak, I.

    1980-01-01

    The modified fractional precipitation of lanthanon-potassium double chromate was used for preliminary separation of gadolinium concentrate containing 60% Gd 2 O 3 , 33,3% Sm 2 O 3 . The 1-st fraction enriched with samarium (60% Sm 2 O 3 ) and 2-nd fraction enriched with gadolinium (80% Gd 2 O 3 with efficiency of 82% recounting on Gd 2 O 3 ) were obtained. Both fractions were separated by the elution with EDTA solution buffered with ammonium acetate. The good results were obtained by ion exchange separation only of the 1-st fraction. (author)

  13. Magnetocaloric properties of distilled gadolinium: effects of structural inhomogeneity and hydrogen impurity

    Czech Academy of Sciences Publication Activity Database

    Burkhanov, G.S.; Kolchugina, N.B.; Tereshina, Evgeniya; Tereshina, I. S.; Politova, G.A.; Chzhan, V.B.; Badurski, D.; Chistyakov, O.D.; Paukov, M.; Drulis, H.; Havela, L.

    2014-01-01

    Roč. 104, č. 24 (2014), "242402-1"-"242402-5" ISSN 0003-6951 R&D Projects: GA ČR GAP204/12/0150 Institutional support: RVO:68378271 Keywords : high-purity rare- earth metals * gadolinium * magnetocaloric effect * hydrogenation * structural studies Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 3.302, year: 2014

  14. Production and characterization of quality gadolinium oxide nanoparticles

    International Nuclear Information System (INIS)

    Hazarika, Samiran; Mohanta, Dambarudhar

    2013-01-01

    Rare earth system Gadolinium (Gd), in either pure form or oxide form, is highly stable against environmental attack. It has immense potential as a contrast agent in magnetic resonance imaging (MRI) devices. Being mechanically and thermally stable it is always difficult to obtain Gd 2 O 3 nanopowders directly from its bulk counterpart using conventional top-down approach. Recently, we have reported production of Gd 2 O 3 nanopowders by first converting bulk Gd 2 O 3 into a nitrate compound and subsequently reduced into a hydroxide product and finally to the oxide product (nanopowder form)

  15. Gadolinium-DOTA enhanced MRI of painful osseous crises in children with sickle cell anemia

    International Nuclear Information System (INIS)

    Bonnerot, V.; Sebag, G.; Montalembert, M. de; Wioland, M.; Glorion, C.; Girot, R.; Lallemand, D.

    1994-01-01

    In order to evaluate the role of gadolinium-DOTA enhanced MRI in the management of painful osseous crises in children with sickle cell anemia (SCA), nine children with SCA underwent MRI, bone scans and ultrasonographic studies during 11 osseous crises. Imaging findings were compared with the final diagnosis: three acute osteomyelitis (AO) and 16 acute infarcts (AI). MRI could not differentiate AO from AI. The appearance of severe AI was very misleading and was similar to the usual appearance of AO, including soft tissue changes, periosteal reaction and patterns of enhancement. Gadolinium-DOTA enhanced MRI was useful for determining the anatomic site and extent of AO or AI and for distinguishing between necrotic material, fluid collection and vascularized inflammatory tissue. It can also help to guide the aspiration of intraosseous, subperiosteal and soft tissue fluid collections. (orig.)

  16. Evolution of the Calcium Paradigm: The Relation between Vitamin D, Serum Calcium and Calcium Absorption

    Directory of Open Access Journals (Sweden)

    Borje E. Christopher Nordin

    2010-09-01

    Full Text Available Osteoporosis is the index disease for calcium deficiency, just as rickets/osteomalacia is the index disease for vitamin D deficiency, but there is considerable overlap between them. The common explanation for this overlap is that hypovitaminosis D causes malabsorption of calcium which then causes secondary hyperparathyroidism and is effectively the same thing as calcium deficiency. This paradigm is incorrect. Hypovitaminosis D causes secondary hyperparathyroidism at serum calcidiol levels lower than 60 nmol/L long before it causes malabsorption of calcium because serum calcitriol (which controls calcium absorption is maintained until serum calcidiol falls below 20 nmol/L. This secondary hyperparathyroidism, probably due to loss of a “calcaemic” action of vitamin D on bone first described in 1957, destroys bone and explains why vitamin D insufficiency is a risk factor for osteoporosis. Vitamin D thus plays a central role in the maintenance of the serum (ionised calcium, which is more important to the organism than the preservation of the skeleton. Bone is sacrificed when absorbed dietary calcium does not match excretion through the skin, kidneys and bowel which is why calcium deficiency causes osteoporosis in experimental animals and, by implication, in humans.

  17. Calcium absorption

    International Nuclear Information System (INIS)

    Carlmark, B.; Reizenstein, P.; Dudley, R.A.

    1976-01-01

    The methods most commonly used to measure the absorption and retention of orally administered calcium are reviewed. Nearly all make use of calcium radioisotopes. The magnitude of calcium absorption and retention depends upon the chemical form and amount of calcium administered, and the clinical and nutritional status of the subject; these influences are briefly surveyed. (author)

  18. Optical properties of pure and Ce3+ doped gadolinium gallium garnet crystals and epitaxial layers

    International Nuclear Information System (INIS)

    Syvorotka, I.I.; Sugak, D.; Wierzbicka, A.; Wittlin, A.; Przybylińska, H.; Barzowska, J.; Barcz, A.; Berkowski, M.; Domagała, J.; Mahlik, S.; Grinberg, M.; Ma, Chong-Geng

    2015-01-01

    Results of X-ray diffraction and low temperature optical absorption measurements of cerium doped gadolinium gallium garnet single crystals and epitaxial layers are reported. In the region of intra-configurational 4f–4f transitions the spectra of the bulk crystals exhibit the signatures of several different Ce 3+ related centers. Apart from the dominant center, associated with Ce substituting gadolinium, at least three other centers are found, some of them attributed to the so-called antisite locations of rare-earth ions in the garnet host, i.e., in the Ga positions. X-ray diffraction data prove lattice expansion of bulk GGG crystals due to the presence of rare-earth antisites. The concentration of the additional Ce-related centers in epitaxial layers is much lower than in the bulk crystals. However, the Ce-doped layers incorporate a large amount of Pb from flux, which is the most probable source of nonradiative quenching of Ce luminescence, not observed in crystals grown by the Czochralski method. - Highlights: • Ce 3+ multicenters found in Gadolinium Gallium Garnet crystals and epitaxial layers. • High quality epitaxial layers of pure and Ce-doped GGG were grown. • Luminescence quenching of Ce 3+ by Pb ions from flux detected in GGG epitaxial layers. • X-ray diffraction allows measuring the amount of the rare-earth antisites in GGG

  19. Preparation of new composite ceramics based on gadolinium-doped ceria and magnesia nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Yao, Jingying; Schelter, Matthias; Zosel, Jens; Oelssner, Wolfram [Kurt-Schwabe-Institut fuer Mess- und Sensortechnik e.V. Meinsberg, Waldheim (Germany); Mertig, Michael [Kurt-Schwabe-Institut fuer Mess- und Sensortechnik e.V. Meinsberg, Waldheim (Germany); Physikalische Chemie, Mess- und Sensortechnik, Technische Universitaet Dresden (Germany)

    2017-09-15

    To achieve solid electrolyte materials for electrochemical energy storage devices with very high oxygen ion conductivity, composites of gadolinium-doped ceria (GDC) and magnesia (MgO) are developed in this study. Three different preparation methods are used to prepare nanoparticles from these two components. According to the characterization results, the self-propagating high-temperature synthesis is best suited for the preparation of both nanometer-sized GDC powder as solid electrolyte and MgO powder as insulator. The structures of the prepared nanometer-sized powders have been characterized by X-ray diffraction and transmission electron microscopy. They show narrow size distributions in the lower nanometer range. Then, dense composite ceramics are prepared from a MgO-GDC mixture by sintering. The size of the crystallite domains in the sintered ceramic is in the upper nanometer range. TEM and TEM-EDX images of a new composite ceramic based on gadolinium-doped ceria and magnesia nanoparticles. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  20. Preparation of new composite ceramics based on gadolinium-doped ceria and magnesia nanoparticles

    International Nuclear Information System (INIS)

    Yao, Jingying; Schelter, Matthias; Zosel, Jens; Oelssner, Wolfram; Mertig, Michael

    2017-01-01

    To achieve solid electrolyte materials for electrochemical energy storage devices with very high oxygen ion conductivity, composites of gadolinium-doped ceria (GDC) and magnesia (MgO) are developed in this study. Three different preparation methods are used to prepare nanoparticles from these two components. According to the characterization results, the self-propagating high-temperature synthesis is best suited for the preparation of both nanometer-sized GDC powder as solid electrolyte and MgO powder as insulator. The structures of the prepared nanometer-sized powders have been characterized by X-ray diffraction and transmission electron microscopy. They show narrow size distributions in the lower nanometer range. Then, dense composite ceramics are prepared from a MgO-GDC mixture by sintering. The size of the crystallite domains in the sintered ceramic is in the upper nanometer range. TEM and TEM-EDX images of a new composite ceramic based on gadolinium-doped ceria and magnesia nanoparticles. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  1. Effects of motexafin gadolinium on DNA damage and X-ray-induced DNA damage repair, as assessed by the Comet assay

    International Nuclear Information System (INIS)

    Donnelly, Erling T.; Liu Yanfeng; Paul, Tracy K.; Rockwell, Sara

    2005-01-01

    Purpose: To investigate the effects of motexafin gadolinium (MGd) on the levels of reactive oxygen species (ROS), glutathione (GSH), and DNA damage in EMT6 mouse mammary carcinoma cells. The ability of MGd to alter radiosensitivity and to inhibit DNA damage repair after X-ray irradiation was also evaluated. Methods and Materials: Reactive oxygen species and GSH levels were assessed by 2,7-dichlorofluorescein fluorescence flow cytometry and the Tietze method, respectively. Cellular radiosensitivity was assessed by clonogenic assays. Deoxyribonucleic acid damage and DNA damage repair were assessed in plateau-phase EMT6 cells by the Comet assay and clonogenic assays. Results: Cells treated with 100 μmol/L MGd plus equimolar ascorbic acid (AA) had significantly increased levels of ROS and a 58.9% ± 3.4% decrease in GSH levels, relative to controls. Motexafin gadolinium plus AA treatment increased the hypoxic, but not the aerobic, radiosensitivity of EMT6 cells. There were increased levels of single-strand breaks in cells treated with 100 μmol/L MGd plus equimolar AA, as evidenced by changes in the alkaline tail moment (MGd + AA, 6 h: 14.7 ± 1.8; control: 2.8 ± 0.9). The level of single-strand breaks was dependent on the length of treatment. Motexafin gadolinium plus AA did not increase double-strand breaks. The repair of single-strand breaks at 2 h, but not at 4 h and 6 h, after irradiation was altered significantly in cells treated with MGd plus AA (MGd + AA, 2 h: 15.8 ± 3.4; control: 5.8 ± 0.6). Motexafin gadolinium did not alter the repair of double-strand breaks at any time after irradiation with 10 Gy. Conclusions: Motexafin gadolinium plus AA generated ROS, which in turn altered GSH homeostasis and induced DNA strand breaks. The MGd plus AA-mediated alteration of GSH levels increased the hypoxic, but not aerobic, radiosensitivity of EMT6 cells. Motexafin gadolinium altered the kinetics of single-strand break repair soon after irradiation but did not

  2. PAMAM Dendrimers as Potential Carriers of Gadolinium Complexes of Iminodiacetic Acid Derivatives for Magnetic Resonance Imaging

    Directory of Open Access Journals (Sweden)

    Magdalena Markowicz-Piasecka

    2015-01-01

    Full Text Available This is the first study describing the utilization of PAMAM dendrimers as delivery vehicles of novel magnetic resonance imaging (MRI contrast agents. The purpose of this paper was to establish the potential of G4 PAMAM dendrimers as carriers of gadolinium complexes of iminodiacetic acid derivatives and determine imaging properties of synthesized compounds in in vivo studies. Furthermore, we examined the influence of four synthesized complexes on the process of clot formation, stabilization, and lysis and on amidolytic activity of thrombin. Biodistribution studies have shown that the compounds composed of PAMAM G4 dendrimers and gadolinium complexes of iminodiacetic acid derivatives increase signal intensity preferably in liver in range of 59–116% in MRI studies which corresponds with the greatest accumulation of gadolinium after administration of the compounds. Synthesized compounds affect kinetic parameters of the proces of clot formation, its stabilization, and lysis. However, only one synthesized compound at concentration 10-fold higher than potential plasma concentrations contributed to the increase of general parameters such as the overall potential of clot formation and lysis (↑CLAUC and total time of the process (↑T. Results of described studies provide additional insight into delivery properties of PAMAM dendrimers but simultaneously underscore the necessity for further research.

  3. Radioisotope 45Ca labeling four calcium chemical compounds and tracing calcium bioavailability

    International Nuclear Information System (INIS)

    Zheng Hui; Zhen Rong; Niu Huisheng; Li Huaifen

    2004-01-01

    Objective: To build up a new method of the radioisotope 45 Ca labeling four calcium chemical compounds, observe and tracing bioavailability change of calcium labeled with radioisotope 45 Ca. Methods: The calcium gluconate (Ca-Glu), calcium citrate (Ca-Cit), calcium carbonate (Ca-Car) and calcium L-threonate (Ca-Thr)were labeled by radioisotope 45 Ca. Four calcium chemical compounds of 45 Ca labeling were used of calcium content 200 mg/kg in the rats and measure the absorption content and bioavailability of calcium in tissue of heart, lever spleen, stomach, kidney, brain, intestine, whole blood, urine, faeces. Results: 1) Radioisotope 45 Ca labeling calcium chemical compound has high radio intensity, more steady standard curve and recover rate. 2) The absorption of organic calcium chemical compounds is higher than the inorganic calcium chemical compound in the study of calcium bioavailability. Conclusion: The method of tracing with radioisotope 45 Ca labeling calcium chemical compounds has the characteristic of the sensitive, objective, accurate and steady in the study of calcium bioavailability

  4. The impact of calcium assay change on a local adjusted calcium equation.

    Science.gov (United States)

    Davies, Sarah L; Hill, Charlotte; Bailey, Lisa M; Davison, Andrew S; Milan, Anna M

    2016-03-01

    Deriving and validating local adjusted calcium equations is important for ensuring appropriate calcium status classification. We investigated the impact on our local adjusted calcium equation of a change in calcium method by the manufacturer from cresolphthalein complexone to NM-BAPTA. Calcium and albumin results from general practice requests were extracted from the Laboratory Information Management system for a three-month period. Results for which there was evidence of disturbance in calcium homeostasis were excluded leaving 13,482 sets of results for analysis. The adjusted calcium equation was derived following least squares regression analysis of total calcium on albumin and normalized to the mean calcium concentration of the data-set. The revised equation (NM-BAPTA calcium method) was compared with the previous equation (cresolphthalein complexone calcium method). The switch in calcium assay resulted in a small change in the adjusted calcium equation but was not considered to be clinically significant. The calcium reference interval differed from that proposed by Pathology Harmony in the UK. Local adjusted calcium equations should be re-assessed following changes in the calcium method. A locally derived reference interval may differ from the consensus harmonized reference interval. © The Author(s) 2015.

  5. Gadolinium-based Contrast Agent Accumulates in the Brain Even in Subjects without Severe Renal Dysfunction: Evaluation of Autopsy Brain Specimens with Inductively Coupled Plasma Mass Spectroscopy.

    Science.gov (United States)

    Kanda, Tomonori; Fukusato, Toshio; Matsuda, Megumi; Toyoda, Keiko; Oba, Hiroshi; Kotoku, Jun'ichi; Haruyama, Takahiro; Kitajima, Kazuhiro; Furui, Shigeru

    2015-07-01

    To use inductively coupled plasma mass spectroscopy (ICP-MS) to evaluate gadolinium accumulation in brain tissues, including the dentate nucleus (DN) and globus pallidus (GP), in subjects who received a gadolinium-based contrast agent (GBCA). Institutional review board approval was obtained for this study. Written informed consent for postmortem investigation was obtained either from the subject prior to his or her death or afterward from the subject's relatives. Brain tissues obtained at autopsy in five subjects who received a linear GBCA (GBCA group) and five subjects with no history of GBCA administration (non-GBCA group) were examined with ICP-MS. Formalin-fixed DN tissue, the inner segment of the GP, cerebellar white matter, the frontal lobe cortex, and frontal lobe white matter were obtained, and their gadolinium concentrations were measured. None of the subjects had received a diagnosis of severely compromised renal function (estimated glomerular filtration rate brain regions. Gadolinium was detected in all specimens in the GBCA agent group (mean, 0.25 µg per gram of brain tissue ± 0.44 [standard deviation]), with significantly higher concentrations in each region (P = .004 vs the non-GBCA group for all regions). In the GBCA group, the DN and GP showed significantly higher gadolinium concentrations (mean, 0.44 µg/g ± 0.63) than other regions (0.12 µg/g ± 0.16) (P = .029). Even in subjects without severe renal dysfunction, GBCA administration causes gadolinium accumulation in the brain, especially in the DN and GP.

  6. Power release estimation inside of fuel pins neighbouring fuel pin with gadolinium in a WWER-1000 type core

    International Nuclear Information System (INIS)

    Mikus, J.

    2006-01-01

    The purpose of this work consists in investigation of the gadolinium fuel pin (fps) influence on space power distribution, especially from viewpoint of the values and gradient occurrence inside of neighbouring FPs that could result in static loads with some consequences, e.g., FP bowing. Since detailed power distributions cannot be obtained in the NPPs, needed information is provided by means of experiments on research reactors. As for the power release measurement inside of FPs, some special (e.g. track) detectors placed between fuel pellets are usually used. Since such works are relatively complicated and time consuming, an evaluation method based on mathematical modelling and numerical approximation was proposed by means of that, and using measured (integral) power release in selected FPs, relevant information about power release inside of needed (investigated) FP, can be obtained. For this purpose, an experiment on light water, zero-power research reactor LR-0 was realized in a WWER-1000 type core with 7 fuel assemblies at zero boron concentration and containing gadolinium FPs. Application of the above evaluation method is demonstrated on investigated FP neighbouring a FP with gadolinium by means of the 1) Azimuthal power distribution inside of investigated FP on their fuel pellet surface in horizontal plane and 2) Gradient of the power distribution inside of investigated FP in two opposite positions on pellets surface that are situated to- and outwards a FP with gadolinium. Similar information can be relevant from the viewpoint of the FP failures occurrence investigation (Authors)

  7. Incorporation of Integral Fuel Burnable Absorbers Boron and Gadolinium into Zirconium-Alloy Fuel Clad Material

    International Nuclear Information System (INIS)

    Sridharan, K.; Renk, T.J.; Lahoda, E.J.; Corradini, M.L

    2004-01-01

    Long-lived fuels require the use of higher enrichments of 235U or other fissile materials. Such high levels of fissile material lead to excessive fuel activity at the beginning of life. To counteract this excessive activity, integral fuel burnable absorbers (IFBA) are added to some rods in the fuel assembly. The two commonly used IFBA elements are gadolinium, which is added as gadolinium-oxide to the UO2 powder, and boron, which is applied as a zirconium-diboride coating on the UO2 pellets using plasma spraying or chemical vapor deposition techniques. The incorporation of IFBA into the fuel has to be performed in a nuclear-regulated facility that is physically separated from the main plant. These operations tend to be very costly because of their small volume and can add from 20 to 30% to the manufacturing cost of the fuel. Other manufacturing issues that impact cost and performance are maintaining the correct levels of dosing, the reduction in fuel melting point due to gadolinium-oxide additions, and parasitic neutron absorption at fuel's end-of-life. The goal of the proposed research is to develop an alternative approach that involves incorporation of boron or gadolinium into the outer surface of the fuel cladding material rather than as an additive to the fuel pellets. This paradigm shift will allow for the introduction of the IFBA in a non-nuclear regulated environment and will obviate the necessity of additional handling and processing of the fuel pellets. This could represent significant cost savings and potentially lead to greater reproducibility and control of the burnable fuel in the early stages of the reactor operation. The surface alloying is being performed using the IBEST (Ion Beam Surface Treatment) process developed at Sandia National Laboratories. IBEST involves the delivery of energetic ion beam pulses onto the surface of a material, near-surface melting, and rapid solidification. The non-equilibrium nature of such processing allows f or surface

  8. Growth and scintillation properties of gadolinium and yttrium orthovanadate crystals

    International Nuclear Information System (INIS)

    Voloshina, O.V.; Baumer, V.N.; Bondar, V.G.; Kurtsev, D.A.; Gorbacheva, T.E.; Zenya, I.M.; Zhukov, A.V.; Sidletskiy, O.Ts.

    2012-01-01

    Aiming to explore the possibility of using the undoped rare-earth orthovanadates as scintillation materials, we developed the procedure for growth of gadolinium (GdVO 4 ) and yttrium (YVO 4 ) orthovanadate single crystals by Czochralski method, and determined the optimal conditions of their after-growth annealing. Optical, luminescent, and scintillation properties of YVO 4 and GdVO 4 were discussed versus known literature data. Scintillation characteristics of GdVO 4 were determined for the first time.

  9. Renal function, nephrogenic systemic fibrosis and other adverse reactions associated with gadolinium-based contrast media.

    Science.gov (United States)

    Canga, Ana; Kislikova, Maria; Martínez-Gálvez, María; Arias, Mercedes; Fraga-Rivas, Patricia; Poyatos, Cecilio; de Francisco, Angel L M

    2014-01-01

    Nephrogenic systemic fibrosis is a fibrosing disorder that affects patients with impaired renal function and is associated with the administration of gadolinium-based contrast media used in MRI. Despite being in a group of drugs that were considered safe, report about this potentially serious adverse reaction was a turning point in the administration guidelines of these contrast media. There has been an attempt to establish safety parameters to identify patients with risk factors of renal failure. The close pharmacovigilance and strict observation of current regulations, with special attention being paid to the value of glomerular filtration, have reduced the published cases involving the use of gadolinium-based contrast media. In a meeting between radiologists and nephrologists we reviewed the most relevant aspects currently and recommendations for its prevention.

  10. Fat-saturated post gadolinium T1 imaging of the brain in multiple sclerosis

    International Nuclear Information System (INIS)

    Al-Saeed, Osama; Sheikh, Mehraj; Ismail, Mohammed; Athyal, Reji

    2011-01-01

    Background Magnetic resonance imaging (MRI) is of vital importance in the diagnosis and follow-up of patients with multiple sclerosis (MS). Imaging sequences better demonstrating enhancing lesions can help in detecting active MS plaques. Purpose To evaluate the role of fat-saturated gadolinium-enhanced T1-weighted (T1W) images of the brain in MS and to assess the benefit of performing this additional sequence in the detection of enhancing lesions. Material and Methods In a prospective study over a six-month period, 70 consecutive patients with clinically diagnosed MS were enrolled. These constituted 14 male and 56 female patients between the ages of 21 and 44 years. All the patients underwent brain MRIs on a 1.5 Tesla Magnet. Gadolinium-enhanced T1 images with and without fat saturation were compared and results were recorded and analyzed using a conspicuity score and McNemar test. Results There were a total of 157 lesions detected in 70 patients on post-contrast T1W fat-saturated images compared with 139 lesions seen on the post-contrast T1W fast spin-echo (FSE) images. This was because 18 of the lesions (11.5%) were only seen on the fat-saturated images. In addition, 15 lesions were more conspicuous on the fat saturation sequence (9.5%). The total conspicuity score obtained, including all the lesions, was 2.24 +/-0.60 (SD). Using the two-tailed McNemar test for quantitative analysis, the P value obtained was <0.0001. Conclusion T1W fat-saturated gadolinium-enhanced images show better lesion enhancement than T1W images without fat saturation

  11. Effects of gadolinium oxide nanoparticles on the oxidative burst from human neutrophil granulocytes

    International Nuclear Information System (INIS)

    Abrikossova, Natalia; Skoglund, Caroline; Ahrén, Maria; Uvdal, Kajsa; Bengtsson, Torbjörn

    2012-01-01

    We have previously shown that gadolinium oxide (Gd 2 O 3 ) nanoparticles are promising candidates to be used as contrast agents in magnetic resonance (MR) imaging applications. In this study, these nanoparticles were investigated in a cellular system, as possible probes for visualization and targeting intended for bioimaging applications. We evaluated the impact of the presence of Gd 2 O 3 nanoparticles on the production of reactive oxygen species (ROS) from human neutrophils, by means of luminol-dependent chemiluminescence. Three sets of Gd 2 O 3 nanoparticles were studied, i.e. as synthesized, dialyzed and both PEG-functionalized and dialyzed Gd 2 O 3 nanoparticles. In addition, neutrophil morphology was evaluated by fluorescent staining of the actin cytoskeleton and fluorescence microscopy. We show that surface modification of these nanoparticles with polyethylene glycol (PEG) is essential in order to increase their biocompatibility. We observed that the as synthesized nanoparticles markedly decreased the ROS production from neutrophils challenged with prey (opsonized yeast particles) compared to controls without nanoparticles. After functionalization and dialysis, more moderate inhibitory effects were observed at a corresponding concentration of gadolinium. At lower gadolinium concentration the response was similar to that of the control cells. We suggest that the diethylene glycol (DEG) present in the as synthesized nanoparticle preparation is responsible for the inhibitory effects on the neutrophil oxidative burst. Indeed, in the present study we also show that even a low concentration of DEG, 0.3%, severely inhibits neutrophil function. In summary, the low cellular response upon PEG-functionalized Gd 2 O 3 nanoparticle exposure indicates that these nanoparticles are promising candidates for MR-imaging purposes. (paper)

  12. Calcium supplements

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/007477.htm Calcium supplements To use the sharing features on this page, please enable JavaScript. WHO SHOULD TAKE CALCIUM SUPPLEMENTS? Calcium is an important mineral for the ...

  13. Removal of gadolinium nitrate from heavy water

    Energy Technology Data Exchange (ETDEWEB)

    Wilde, E.W.

    2000-03-22

    Work was conducted to develop a cost-effective process to purify 181 55-gallon drums containing spent heavy water moderator (D2O) contaminated with high concentrations of gadolinium nitrate, a chemical used as a neutron poison during former nuclear reactor operations at the Savannah River Site (SRS). These drums also contain low level radioactive contamination, including tritium, which complicates treatment options. Presently, the drums of degraded moderator are being stored on site. It was suggested that a process utilizing biological mechanisms could potentially lower the total cost of heavy water purification by allowing the use of smaller equipment with less product loss and a reduction in the quantity of secondary waste materials produced by the current baseline process (ion exchange).

  14. Studies of MRI relaxivities of gadolinium-labeled dendrons

    Science.gov (United States)

    Pan, Hongmu; Daniel, Marie-Christine

    2011-05-01

    In cancer detection, imaging techniques have a great importance in early diagnosis. The more sensitive the imaging technique and the earlier the tumor can be detected. Contrast agents have the capability to increase the sensitivity in imaging techniques such as magnetic resonance imaging (MRI). Until now, gadolinium-based contrast agents are mainly used for MRI, and show good enhancement. But improvement is needed for detection of smaller tumors at the earliest stage possible. The dendrons complexed with Gd(DOTA) were synthesized and evaluated as a new MRI contrast agent. The longitudinal and transverse relaxation effects were tested and compared with commercial drug Magnevist, Gd(DTPA).

  15. Effects of gadolinium-based MRI contrast agents on liver tissue.

    Science.gov (United States)

    Mercantepe, Tolga; Tümkaya, Levent; Çeliker, Fatma Beyazal; Topal Suzan, Zehra; Çinar, Seda; Akyildiz, Kerimali; Mercantepe, Filiz; Yilmaz, Adnan

    2018-04-01

    MRI with contrast is often used clinically. However, recent studies have reported a high accumulation of gadolinium-based contrast agents (GBCAs) in kidney, liver, and spleen tissues in several mouse models. To compare the effects on liver tissue of gadolinium-based MRI contrast agents in the light of biochemical and histopathological evaluation. Institutional Review Board (IRB)-approved controlled longitudinal study. In all, 32 male Sprague-Dawley rats were divided into a healthy control group subjected to no procedure (Group 1), a sham group (Group 2), a gadodiamide group (Group 3), and a gadoteric acid group (Group 4). Not applicable. Liver tissues removed at the end of the fifth week and evaluated pathologically (scored Knodell's histological activity index [HAI] method by two histopathologists) immunohistochemical (caspase-3 and biochemical tests (AST, ALT, TAS, TOS, and OSI method by Erel et al) were obtained. Differences between groups were analyzed using the nonparametric Kruskal-Wallis test followed by the Tamhane test, and one-way analysis of variance (ANOVA) followed by Turkey's HSD test. An increase was observed in histological activity scores in sections from rats administered gadodiamide and gadoteric acid, and in caspase-3, AST and ALT values (P total antioxidant and antioxidant capacity. 1 Technical Efficacy: Stage 4 J. Magn. Reson. Imaging 2018. © 2018 International Society for Magnetic Resonance in Medicine.

  16. Calcium waves.

    Science.gov (United States)

    Jaffe, Lionel F

    2008-04-12

    Waves through living systems are best characterized by their speeds at 20 degrees C. These speeds vary from those of calcium action potentials to those of ultraslow ones which move at 1-10 and/or 10-20 nm s(-1). All such waves are known or inferred to be calcium waves. The two classes of calcium waves which include ones with important morphogenetic effects are slow waves that move at 0.2-2 microm s(-1) and ultraslow ones. Both may be propagated by cycles in which the entry of calcium through the plasma membrane induces subsurface contraction. This contraction opens nearby stretch-sensitive calcium channels. Calcium entry through these channels propagates the calcium wave. Many slow waves are seen as waves of indentation. Some are considered to act via cellular peristalsis; for example, those which seem to drive the germ plasm to the vegetal pole of the Xenopus egg. Other good examples of morphogenetic slow waves are ones through fertilizing maize eggs, through developing barnacle eggs and through axolotl embryos during neural induction. Good examples of ultraslow morphogenetic waves are ones during inversion in developing Volvox embryos and across developing Drosophila eye discs. Morphogenetic waves may be best pursued by imaging their calcium with aequorins.

  17. Absorbability of calcium from calcium-bound phosphoryl oligosaccharides in comparison with that from various calcium compounds in the rat ligated jejunum loop.

    Science.gov (United States)

    To-o, Kenji; Kamasaka, Hiroshi; Nishimura, Takahisa; Kuriki, Takashi; Saeki, Shigeru; Nakabou, Yukihiro

    2003-08-01

    Calcium-bound phosphoryl oligosaccharides (POs-Ca) were prepared from potato starch. Their solubility and in situ absorbability as a calcium source were investigated by comparing with the soluble calcium compounds, calcium chloride and calcium lactate, or insoluble calcium compounds, calcium carbonate and dibasic calcium phosphate. The solubility of POs-Ca was as high as that of calcium chloride and about 3-fold higher than that of calcium lactate. An in situ experiment showed that the intestinal calcium absorption rate of POs-Ca was almost comparable with that of the soluble calcium compounds, and was significantly higher (pcalcium groups. Moreover, the total absorption rate of a 1:1 mixture of the calcium from POs-Ca and a whey mineral complex (WMC) was significantly higher (psoluble calcium source with relatively high absorption in the intestinal tract.

  18. Dynamic gadolinium-enhanced subtraction MR imaging - a simple technique for the early diagnosis of Legg-Calve-Perthes disease: preliminary results

    International Nuclear Information System (INIS)

    Sebag, G.; Ducou Le Pointe, H.; Klein, I.; Maiza, D.; Mazda, K.; Bensahel, H.; Hassan, M.

    1997-01-01

    To determine whether the simple technique of dynamic gadolinium-enhanced subtraction MR imaging, which is available on standard MR units, can detect ischemia of the femoral head in children with early Legg-Calve-Perthes disease (LCP). Bone perfusion of eight hips in four patients (mean age 7.5 years) was studied using dynamic gadolinium-enhanced substraction MR imaging at the onset of proven LCP (with initial negative plain films). Enhancement of subtracted images was compared with that on standard MR images and with bone scintigraphy findings. Subtraction MR imaging depicted ischemia as a widespread absence of enhancement and was in good agreement with bone scintigraphy. The subtraction technique improved the sensitivity and the specificity of MR imaging in two children. Furthermore, subtraction MR imaging allowed recognition of the pattern of early reperfusion. Our preliminary results indicate that dynamic gadolinium-enhanced subtraction MRI is a simple and promising means of early recognition of ischemia in LCP. (orig.)

  19. Gadolinium-enhanced MR angiography of arterial occlusive disease in lower extremity : comparison with conventional digital subtraction angiography

    International Nuclear Information System (INIS)

    Shin, Sang June; Koh, Young Hwan; Cha, Joo Hee; Kim, Hyu Beom; Chung, Jin Wook; Park, Jae Hyung

    2000-01-01

    To compare the diagnostic value of gadolinium-enhanced MR angiography with that of conventional digital subtraction angiography for the evaluation of lower extremity arterial occlusive diseases. In 26 patients with symptomatic lower extremity arterial occlusive disease, both conventional digital subtraction angiography (DSA) and gadolinium-enhanced MR angiography (CE-MRA) were performed during the same week. MR angiography was performed using three-dimensional gradient-echo acquisition before, and two sequential acquisitions after, the administration of gadolinium (0.2 mmol/kg). In 23 patients, two separate, contiguous areas were scanned using additional doses. In three patients, only one field with a suspicious lesion was scanned. Three radiologists independently analyzed the CE-MRA and DSA findings of each vascular segment (20 segments per arterial tree) for the presence of obstructive lesions; the grade assigned was either mild or none (less than 50%), stenotic (50%-99%), or occlusion (100%). From among a total of 462 segments, DSA detected 99 which were significantly narrowed (stenosis, 33; occlusion, 66). Using MR angiography, 102 segments (stenosis 39; occlusion, 63) were identified, and 94 lesions (stenosis, 32; occlusion, 62) were graded correctly. Seven lesions were overestimated and four were underestimated. For the detection of hemodynamically significant stenosis or occlusions using MR angiography, sensitivity, specificity, and diagnostic accuracy were 95%, 98%, and 98% (G=3D0.995, P less than 0.001), respectively. To prove the absence of lesions, we repeated DSA in two patients with arterial spasm due to puncture. Three occluded segments seen on DSA, which revealed intact segments on MR angiography, suggested slow distal flow after reconstitution. For the evaluation of lower extremity arterial occlusive disease, the diagnostic value of gadolinium-enhanced MR angiography is comparable with that of digital subtraction angiography. The advantages of the

  20. Montecarlo calculation for a benchmark on interactive effects of Gadolinium poisoned pins in BWRs

    International Nuclear Information System (INIS)

    Borgia, M.G.; Casali, F.; Cepraga, D.

    1985-01-01

    K infinite and burn-up calculations have been done in the frame of a benchmark organized by Physic Reactor Committee of NEA. The calculations, performed by the Montecarlo code KIM, concerned BWR lattices having UO*L2 fuel rodlets with and without gadolinium oxide

  1. Gadolinium-DTPA enhanced magnetic resonance imaging of bone cysts in patients with rheumatoid arthritis

    NARCIS (Netherlands)

    Gubler, F. M.; Algra, P. R.; Maas, M.; Dijkstra, P. F.; Falke, T. H.

    1993-01-01

    To examine the contents of intraosseous cysts in patients with rheumatoid arthritis (RA) through the signal intensity characteristics on gadolinium-DTPA (Gd-DTPA) enhanced magnetic resonance imaging. The hand or foot joints of nine patients with the cystic form of RA (where the initial radiological

  2. Get Enough Calcium

    Science.gov (United States)

    ... Calcium Print This Topic En español Get Enough Calcium Browse Sections The Basics Overview Foods and Vitamins ... women, don't get enough calcium. How much calcium do I need every day? Women: If you ...

  3. Selective Filtration of Gadolinium Trichloride for Use in Neutron Detection in Large Water Cherenkov Detectors

    International Nuclear Information System (INIS)

    Vagins, Mark R.

    2013-01-01

    Super-??Kamiokande Water Cherenkov detectors have been used for many years as inexpensive, effective detectors for neutrino interactions and nucleon decay searches. While many important measurements have been made with these detectors a major drawback has been their inability to detect the absorption of thermal neutrons. We believe an inexpensive, effective technique could be developed to overcome this situation via the addition to water of a solute with a large neutron cross section and energetic gamma daughters which would make neutrons detectable. Gadolinium seems an excellent candidate especially since in recent years it has become very inexpensive, now less than $8 per kilogram in the form of commercially-available gadolinium trichloride, GdCl 3 . This non-toxic, non-reactive substance is highly soluble in water. Neutron capture on gadolinium yields a gamma cascade which would be easily seen in detectors like Super-Kamiokande. We have been investigating the use of GdCl 3 as a possible upgrade for the Super-Kamiokande detector with a view toward improving its performance as a detector for atmospheric neutrinos, supernova neutrinos, wrong-sign solar neutrinos, reactor neutrinos, proton decay, and also as a target for the coming T2K long-baseline neutrino experiment. This focused study of selective water filtration and GdCl 3 extraction techniques, conducted at UC Irvine, followed up on highly promising benchtop-scale and kiloton-scale work previously carried out with the assistance of 2003 and 2005 Advanced Detector Research Program grants

  4. The Effects of Dietary Calcium and/or Iron Deficiency upon Murine Intestinal Calcium Binding Protein Activity and Calcium Absorption

    OpenAIRE

    McDonald, Catherine M.

    1980-01-01

    Iron deficiency has been shown to impair calcium absorption, leading to decreased bone mass. Vitamin D3-dependent calcium binding protein (CaBP) has been demonstrated to be necessary for the active transport of calcium in the intestine of numerous species. Iron deficiency might affect the activity of the calcium binding protein. Four experimental diets were formulated as follows: Diet 1, iron adequate, calcium adequate; Diet 2, iron deficient, calcium adequate; Diet 3, iron adequate, calci...

  5. Effects of diphosphonate on kidney calcium content and duodenal absorption of 45calcium

    International Nuclear Information System (INIS)

    Goulding, A.; Cameron, V.

    1978-01-01

    In rats the relationships between EHDP-induced changes in serum calcium concentration, kidney calcium content and duodenal transport of 45 calcium were studied. Body weights and kidney weights were similar in all groups. EHDP administration was associated with an increase in serum calcium concentration and kidney calcium content, and a decrease in duodenal 45 calcium transport. In the EHDP-treated rats, there was a significant negative correlation between kidney calcium concentration and duodenal 45 calcium transport but no correlation between either kidney calcium content and serum calcium concentration (r = 0.116) or between serum calcium concentration and duodenal 45 calcium transport (r = 0.02). Further experiments will be needed to determine whether the demonstrated increase in kidney calcium content induced by EHDP administration was the cause of, or was secondary to, inhibition of 1, 25(OH) 2 D 3 synthesis. (orig./AJ) [de

  6. Effect of lowering dietary calcium intake on fractional whole body calcium retention

    International Nuclear Information System (INIS)

    Dawson-Hughes, B.; Stern, D.T.; Shipp, C.C.; Rasmussen, H.M.

    1988-01-01

    Although fractional calcium absorption is known to vary inversely with calcium intake, the extent and timing of individual hormonal and calcium absorption responses to altered calcium intake have not been defined. We measured fractional whole body retention of orally ingested 47 Ca, an index of calcium absorption, in nine normal women after they had eaten a 2000-mg calcium diet for 8 weeks and a 300-mg calcium diet for 1, 2, 4, and 8 weeks. After the diet change, serum intact PTH (32.2% increase; P = 0.005), serum 1,25-dihydroxyvitamin D [1,25-(OH)2D; 43.8% increase; P = 0.003], and fractional whole body calcium retention (42.8% increase; P = 0.004) increased within 1 week. Although the PTH and calcium retention responses remained fairly constant throughout the low calcium intake period, serum 1,25-(OH)2D concentrations declined toward baseline after week 1. Thus, the late increase in calcium retention may have resulted from calcium absorption that was independent of 1,25-(OH)2D stimulation

  7. Implementation of a Gadolinium Burnable Absorber in the Carbide LEU-NTR

    International Nuclear Information System (INIS)

    Venneria, Paolo; Kim, Yonghee

    2015-01-01

    Among the most crucial are the rapid reactivity depletion during full-power operation and the positive reactivity insertion during the full-submersion criticality accident. In previous work, it has been suggested that both challenges can be mitigated through the successful implementation of a burnable absorber in the active core. Of the poisons previously surveyed, one of the most promising is Gadolinium in the form of Gadolina (Gd2O4). This paper explores the possibility of different methods by which the Gadolinia can be implemented in the core and makes a preliminary study of its effect on the full submersion criticality accident and the reactivity depletion during operation. The application of a Gadolinium neutron absorber in the active core region of the LEU-NTR has been shown to be neutronically feasible. It can be introduced into the core in various locations without resulting in core performance loss. The utility of the poison in terms of mitigating the full-submersion reactivity accident and the rapid change in reactivity during full-power operation have been preliminarily shown and the first steps towards eventual implementation made. Future work will consist of determining the maximum poison content in the core and tailoring the self-shielding effect in order to determine a specific Gd depletion rate

  8. Are gadolinium contrast agents suitable for gadolinium neutron capture therapy?

    Science.gov (United States)

    De Stasio, Gelsomina; Rajesh, Deepika; Casalbore, Patrizia; Daniels, Matthew J; Erhardt, Robert J; Frazer, Bradley H; Wiese, Lisa M; Richter, Katherine L; Sonderegger, Brandon R; Gilbert, Benjamin; Schaub, Sebastien; Cannara, Rachel J; Crawford, John F; Gilles, Mary K; Tyliszczak, Tolek; Fowler, John F; Larocca, Luigi M; Howard, Steven P; Mercanti, Delio; Mehta, Minesh P; Pallini, Roberto

    2005-06-01

    Gadolinium neutron capture therapy (GdNCT) is a potential treatment for malignant tumors based on two steps: (1) injection of a tumor-specific (157)Gd compound; (2) tumor irradiation with thermal neutrons. The GdNC reaction can induce cell death provided that Gd is proximate to DNA. Here, we studied the nuclear uptake of Gd by glioblastoma (GBM) tumor cells after treatment with two Gd compounds commonly used for magnetic resonance imaging, to evaluate their potential as GdNCT agents. Using synchrotron X-ray spectromicroscopy, we analyzed the Gd distribution at the subcellular level in: (1) human cultured GBM cells exposed to Gd-DTPA or Gd-DOTA for 0-72 hours; (2) intracerebrally implanted C6 glioma tumors in rats injected with one or two doses of Gd-DOTA, and (3) tumor samples from GBM patients injected with Gd-DTPA. In cell cultures, Gd-DTPA and Gd-DOTA were found in 84% and 56% of the cell nuclei, respectively. In rat tumors, Gd penetrated the nuclei of 47% and 85% of the tumor cells, after single and double injection of Gd-DOTA, respectively. In contrast, in human GBM tumors 6.1% of the cell nuclei contained Gd-DTPA. Efficacy of Gd-DTPA and Gd-DOTA as GdNCT agents is predicted to be low, due to the insufficient number of tumor cell nuclei incorporating Gd. Although multiple administration schedules in vivo might induce Gd penetration into more tumor cell nuclei, a search for new Gd compounds with higher nuclear affinity is warranted before planning GdNCT in animal models or clinical trials.

  9. Preparation, characterization and optical properties of Gadolinium doped ceria thin films by pulsed laser deposition technique

    International Nuclear Information System (INIS)

    Nagaraju, P.; Vijaya Kumar, Y.; Vishnuvardhan Reddy, C.; Ramana Reddy, M.V.; Phase, D.M; Raghavendra Reddy, V.

    2013-01-01

    The growth of Gadolinium doped ceria thin films with controlled surface structure for device quality applications presents a significant problem for experimental investigation. In the present study gadolinium doped cerium oxide thin films were prepared by pulsed laser deposition (PLD) and were studied for their surface structure evaluation in relation to the optimized operating conditions during the stage of film preparation. The deposition was made with gadolinium concentration of 10 mole% to ceria pellets. The films were deposited on quartz substrate in the presence of oxygen partial pressure of 1.5 x 10 -3 torr using KrF Excimer laser with laser energy 220 mJ at a substrate temperature 700℃. The effect of annealing temperature on 10 mole% GDC thin film was investigated. The film thickness was measured by using AMBIOS make XP-l stylus profiler. As prepared and annealed thin films were characterized for crystallinity, particle size and orientation by using G.I.XRD. The films were characterized using atomic force microscopy (AFM). The AFM results gave a consistent picture of the evolution of GDC film surface morphologies and microstructures in terms of surface roughness, grain distribution and mean grain size. The optical transmittance spectra was used to determine the optical constants such as optical band gap, refractive index, extinction coefficient of as prepared and annealed thin films. (author)

  10. Gadolinium based contrast agents in current practice: Risks of accumulation and toxicity in patients with normal renal function

    Directory of Open Access Journals (Sweden)

    Anju Ranga

    2017-01-01

    Full Text Available Despite being decked as the most prized compounds in the nugget box of contrast agents for clinical radiologists, and carrying an indisputable tag of safety of the US Food and Drug Administration for close to three decades, all may not be seemingly well with the family of gadolinium compounds. If the first signs of violations of primum non nocere in relation to gadolinium-based contrast agents (GBCAs appeared in the millennium year with the first published report of skin fibrosis in patients with compromised renal function, the causal relationship between the development of nephrogenic systemic fibrosis (NSF and GBCAs, first proposed by two European groups in 2006, further precluded their use in renocompromised patients. The toxicity, pharmacokinetics, and pharmacodynamics of GBCAs, however, has come under hawk-eyed scrutiny with recent reports that gadolinium tends to deposit cumulatively in the brain of patients with normal hepatobiliary function and intact blood–brain barrier. While the jury on the long-term hazard significance of this critical scientific finding is still out, the use of GBCAs must be guided by due clinical diligence, avoidance of repeated doses, and preferring GBCAs with the best safety profiles.

  11. Reaction of gadolinium chelates with ozone and hydroxyl radicals.

    Science.gov (United States)

    Cyris, Maike; Knolle, Wolfgang; Richard, Jessica; Dopp, Elke; von Sonntag, Clemens; Schmidt, Torsten C

    2013-09-03

    Gadolinium chelates are used in increasing amounts as contrast agents in magnetic resonance imaging, and their fate in wastewater treatment has recently become the focus of research. Oxidative processes, in particular the application of ozone, are currently discussed or even implemented for advanced wastewater treatment. However, reactions of the gadolinium chelates with ozone are not yet characterized. In this study, therefore, rate constants with ozone were determined for the three commonly used chelates Gd-DTPA, Gd-DTPA-BMA, and Gd-BT-DO3A, which were found to be 4.8 ± 0.88, 46 ± 2.5, and 24 ± 1.5 M(-1) s(-1), respectively. These low rate constants indicate that a direct reaction with ozone in wastewater is negligible. However, application of ozone in wastewater leads to substantial yields of (•)OH. Different methods have been applied and compared for determination of k((•)OH+Gd chelate). From rate constants determined by pulse radiolysis experiments (k((•)OH+Gd-DTPA) = 2.6 ± 0.2 × 10(9) M(-1) s(-1), k((•)OH+Gd-DTPA-BMA) = 1.9 ± 0.7 × 10(9) M(-1) s(-1), k((•)OH+Gd-BT-DO3A) = 4.3 ± 0.2 × 10(9) M(-1) s(-1)), it is concluded that a reaction in wastewater via (•)OH radicals is feasible. Toxicity has been tested for educt and product mixtures of both reactions. Cytotoxicity (MTT test) and genotoxicity (micronuclei assay) were not detectable.

  12. Corrosion of gadolinium aluminate-aluminium oxide samples in fully desalinated water at 575 K

    International Nuclear Information System (INIS)

    Hattenbach, K.; Zimmermann, H.U.

    1978-07-01

    Corrosion tests have been carried out for 1 1/2 years on gadolinium aluminate/aluminium oxide samples (burnable poison for ship propulsion reactors) with and without cans at 575 K in fully desalinated water. It was found that this substance is highly corrosion-resistant. (orig./HP) [de

  13. Structural and Chemical Analysis of Gadolinium Halides Encapsulated within WS 2 Nanotubes

    KAUST Repository

    Anumol, E A

    2016-05-18

    The hollow cavities of nanotubes could serve as templates for the growth of size- and shape-confined functional nanostructures, giving rise to novel materials and properties. In this work, considering their potential application as MRI contrast agents, gadolinium halides are encapsulated within the hollow cavities of inorganic nanotubes of WS2 by capillary filling to obtain GdX3@WS2 nanotubes (where X = Cl, Br or I and @ means encapsulated in). Aberration corrected scanning/transmission electron microscopy (S/TEM) and spectroscopy is employed to understand the morphology and composition of the GdI3@WS2 nanotubes. The three dimensional morphology is studied with STEM tomography but understanding the compositional information is a non-trivial matter due to the presence of multiple high atomic number elements. Therefore, energy dispersive X-ray spectroscopy (EDS) tomography was employed revealing the three dimensional chemical composition. Molecular dynamics simulations of the filling procedure shed light into the mechanics behind the formation of the confined gadolinium halide crystals. The quasi-1D system employed here serves as an example of a TEM-based chemical nanotomography method that could be extended to other materials, including beam-sensitive soft materials.

  14. Structural and Chemical Analysis of Gadolinium Halides Encapsulated within WS 2 Nanotubes

    KAUST Repository

    Anumol, E A; Enyashin, Andrey; Batra, Nitin M; Da Costa, Pedro M. F. J.; Francis, Leonard Deepak

    2016-01-01

    The hollow cavities of nanotubes could serve as templates for the growth of size- and shape-confined functional nanostructures, giving rise to novel materials and properties. In this work, considering their potential application as MRI contrast agents, gadolinium halides are encapsulated within the hollow cavities of inorganic nanotubes of WS2 by capillary filling to obtain GdX3@WS2 nanotubes (where X = Cl, Br or I and @ means encapsulated in). Aberration corrected scanning/transmission electron microscopy (S/TEM) and spectroscopy is employed to understand the morphology and composition of the GdI3@WS2 nanotubes. The three dimensional morphology is studied with STEM tomography but understanding the compositional information is a non-trivial matter due to the presence of multiple high atomic number elements. Therefore, energy dispersive X-ray spectroscopy (EDS) tomography was employed revealing the three dimensional chemical composition. Molecular dynamics simulations of the filling procedure shed light into the mechanics behind the formation of the confined gadolinium halide crystals. The quasi-1D system employed here serves as an example of a TEM-based chemical nanotomography method that could be extended to other materials, including beam-sensitive soft materials.

  15. Calcium signals can freely cross the nuclear envelope in hippocampal neurons: somatic calcium increases generate nuclear calcium transients

    Directory of Open Access Journals (Sweden)

    Bading Hilmar

    2007-07-01

    Full Text Available Abstract Background In hippocampal neurons, nuclear calcium signaling is important for learning- and neuronal survival-associated gene expression. However, it is unknown whether calcium signals generated by neuronal activity at the cell membrane and propagated to the soma can unrestrictedly cross the nuclear envelope to invade the nucleus. The nuclear envelope, which allows ion transit via the nuclear pore complex, may represent a barrier for calcium and has been suggested to insulate the nucleus from activity-induced cytoplasmic calcium transients in some cell types. Results Using laser-assisted uncaging of caged calcium compounds in defined sub-cellular domains, we show here that the nuclear compartment border does not represent a barrier for calcium signals in hippocampal neurons. Although passive diffusion of molecules between the cytosol and the nucleoplasm may be modulated through changes in conformational state of the nuclear pore complex, we found no evidence for a gating mechanism for calcium movement across the nuclear border. Conclusion Thus, the nuclear envelope does not spatially restrict calcium transients to the somatic cytosol but allows calcium signals to freely enter the cell nucleus to trigger genomic events.

  16. Calcium hydroxide isotope effect in calcium isotope enrichment by ion exchange

    International Nuclear Information System (INIS)

    Jepson, B.E.; Shockey, G.C.

    1984-01-01

    The enrichment of calcium isotopes has been observed in ion-exchange chromatography with an aqueous phase of calcium hydroxide and a solid phase of sulfonic acid resin. The band front was exceedingly sharp as a result of the acid-base reaction occuring at the front of the band. Single-stage separation coefficients were found to be epsilon( 44 Ca/ 40 Ca) = 11 x 10 -4 and epsilon( 48 Ca/ 40 Ca) = 18 x 10 -4 . The maximum column separation factors achieved were 1.05 for calcium-44 and 1.09 for calcium-48 with the heavy isotopes enriching in the fluid phase. The calcium isotope effect between fully hydrated aqueous calcium ions and undissociated aqueous calcium hydroxide was estimated. For the calcium-44/40 isotope pair the separation coefficient was 13 x 10 -4 . 20 references, 2 figures

  17. Study on the uptake and distribution of gadolinium based contrast agents in biological samples using laser ablation with inductively coupled plasma mass spectroscopy

    International Nuclear Information System (INIS)

    Lingott, Jana

    2016-01-01

    Gadolinium based contrast agents are used for magnetic resonance imaging. After their excretion by medicated patients they reach surface water passing waste water treatment plants where they are not removed sufficiently. The behavior of the contrast agents in the environment and the interaction with organisms was investigated in this work due to the toxicity of the free Gd 3+ ion and the associated risks, such as accumulation in the human food chain. In this work, the two elemental analytical imaging methods laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) and synchrotron radiation X-ray fluorescence analysis (SRXRF) have been used to investigate the uptake, distribution, and excretion of Gd-based contrast agents by various biological systems. Both methods were analytically characterized and compared for this application. The detection limits of gadolinium were determined under optimized conditions by LA-ICP-MS and SRXRF. With calibration by remains of dried elemental standard droplets detection limits of 0.78 pg absolute amount of gadolinium (LA-ICP-MS), respectively 89 pg (SRXRF) were reached. Based on filamentous algae as water plants the uptake and the excretion of Gd-based contrast agents were revealed. The dependence on concentration of the contrast agent in the exposition solution and the independence of temporal uptake within one to seven days were studied for duckweed. By LA-ICP-MS gadolinium was quantified in a leaf of cress plant. The verification of the results was performed by SRXRF and ICP-MS after digestion. Furthermore, the uptake and distribution of Gd-based contrast agents in higher organisms (water flea) were observed. The exact location of gadolinium was resolved by three-dimensional μ-computed tomography by the comparison of an exposed with a Gd-free water flea. In all studies, gadolinium was detected in the investigated exposed model organisms. It can be concluded that the contrast agents were taken from the environment.

  18. Gadolinium-enhanced MR imaging in evaluation of Bell palsy

    International Nuclear Information System (INIS)

    Wang, A.M.; Wesolowski, D.P.; Bojrab, D.I.; Ernstoff, R.M.; Farah, J.

    1989-01-01

    Eight patients with Bell palsy were evaluated with Gd-DTPA (Magnevist)-enhanced MR imaging in a 1.0-T Siemen's Magnetom unit. Axial pre-and postcontrast and coronal postcontrast T1-weighted MR images of facial nerves were studied. Significant unilateral enhancement of the facial nerve within the internal auditory canal, with or without involvement of the geniculate ganglia, was found in six patients. Three of these patients without satisfactory response to medical treatment underwent surgical decompression, with excellent recovery of facial nerve function. The authors believe that gadolinium-enhanced MR imaging is valuable in the evaluation and management of Bell palsy

  19. Calcium

    Science.gov (United States)

    ... You can get decent amounts of calcium from baked beans, navy beans, white beans, and others. Canned fish. You're in luck if you like sardines and canned salmon with bones. Almond milk. Working Calcium Into Your ...

  20. Peculiarities of gadolinium molybdate change-over using alternating electric field

    International Nuclear Information System (INIS)

    Alekseev, A.N.; Zlokazov, M.V.; Prokolov, A.L.; Tikhomirova, N.A.; Shuvalov, L.A.; AN SSSR, Moscow. Inst. Kristallografii)

    1984-01-01

    Experimental investigation into processes of total repolarization of a gadolinium molybdate monocrystal Gd(MoO 4 ) 3 -GMO following alternating electric effects is conduced. The process of total change-over of the GMO monocrystal with a capillar layer of weak-conductive liquid deposited on its polar surfaces at application of alternating stationary electric field is shown to proceed through sidewise traverse of the single plane domain boundary of one and the same crystallographical orientation (110) in the coordinate system of monodomain state being changed-over

  1. Peculiarities of gadolinium molybdate change-over using alternating electric field

    Energy Technology Data Exchange (ETDEWEB)

    Alekseev, A N; Zlokazov, M V; Prokolov, A L; Tikhomirova, N A; Shuvalov, L A [Moskovskij Inzhenerno-Fizicheskij Inst. (USSR); AN SSSR, Moscow. Inst. Kristallografii)

    1984-06-01

    Experimental investigation into processes of total repolarization of a gadolinium molybdate monocrystal Gd(MoO/sub 4/)/sub 3/-GMO following alternating electric effects is conduced. The process of total change-over of the GMO monocrystal with a capillar layer of weak-conductive liquid deposited on its polar surfaces at application of alternating stationary electric field is shown to proceed through sidewise traverse of the single plane domain boundary of one and the same crystallographical orientation (110) in the coordinate system of monodomain state being changed-over.

  2. Influence of dietary calcium on bone calcium utilization

    International Nuclear Information System (INIS)

    Farmer, M.; Roland, D.A. Sr.; Clark, A.J.

    1986-01-01

    In Experiment 1, 10 microCi 45 Ca/day were administered to 125 hens for 10 days. Hens were then allocated to five treatments with calcium levels ranging from .08 to 3.75% of the diet. In Experiment 2, hens with morning oviposition times were randomly allocated to 11 treatments that were periods of time postoviposition ranging from 6 hr to 24 hr, in 2-hr increments (Experiment 2). At the end of each 2-hr period, eggs from 25 hens were removed from the uterus. The 18-, 20-, and 22-hr treatments were replicated three times. In Experiment 3, hens were fed either ad libitum or feed was withheld the last 5 or 6 hr before oviposition. In Experiment 4, hens were fed 10 microCi of 45 Ca for 15 days to label skeletal calcium. Hens were divided into two groups and fed a .08 or 3.75% calcium diet for 2 days. On the second day, 25 hens fed the 3.75% calcium diet were intubated with 7 g of the same diet containing .5 g calcium at 1700, 2100, 0100, 0500, and 0700 hr. The measurements used were egg weight, shell weight, and 45 Ca content of the egg shell. Results indicated a significant linear or quadratic regression of dietary calcium levels on 45 Ca accumulation in eggshells and eggshell weight (Experiment 1). As the calcium level of the diet increased, eggshell weight increased and 45 Ca recovery decreased. Utilization of skeletal calcium for shell formation ranged from 28 to 96%. In Experiment 2, the rate of shell calcification was not constant throughout the calcification process but varied significantly

  3. Proton NMR relaxivity of blood samples in the presence of some gadolinium and dysprosium compounds

    International Nuclear Information System (INIS)

    Coroiu, I.; Darabont, Al.; Bogdan, M.

    1999-01-01

    The use of some new compounds in MRI tissue and blood characterisation based on nuclear spin relaxation time measurements cannot be sustained until the molecular sources of these variations are understood. Tissues and blood are complex molecular systems with complex NMR properties. A better comprehension of the molecular basis of relaxation offers the possibility to predict the changes expected for a given pathology. The purpose of this contribution is to evidence the different relaxation characteristics of some gadolinium and dysprosium compounds in the presence and absence of the blood and to give a possible explanation about the molecular processes that cause occurrence of changes. Some gadolinium and dysprosium compounds such as: Gd-CIT (gadolinium citrate), Dy-DTPA (DTPA-diethylenetriamine pentaacetic acid), iron oxide - gadolinium oxide (or dysprosium oxide)- dextran complexes were prepared. The longitudinal T 1 -1 and transverse T 2 -1 'relaxation rates' measurements have been carried out as a function of molar concentrations. All measurements have been made at room temperature (about 25 deg.C) and the proton Larmor frequency ν o = 90 MHz. The pulsed NMR spectrometer utilised was a commercial Bruker SXP4/100 spectrometer. Transverse relaxation rate measurements have been made using the Carr-Purcell method, while longitudinal relaxation rate measurements using the inversion recovery pulse sequence, 180 angle-τ-90 angle. The accuracy was about 2-3% for the longitudinal relaxation rates and about 5-7% for the transverse relaxation rates. R 1 and R 2 relaxivities, in mM -1 s -1 were determined from the least square determination of the slopes of plots 1/T 1,2 versus compound molar concentration, using at least five independent measurements at several concentrations between 0 and 2 mM. Increased R 2 relaxivity observed for dysprosium compounds in the blood presence can be explained by PRE effect. The largest gain in R 2 relaxivity seems to imply a noncovalent

  4. Calcium D-saccharate

    DEFF Research Database (Denmark)

    Garcia, André Castilho; Hedegaard, Martina Vavrusova; Skibsted, Leif Horsfelt

    2016-01-01

    Molar conductivity of saturated aqueous solutions of calcium d-saccharate, used as a stabilizer of beverages fortified with calcium d-gluconate, increases strongly upon dilution, indicating complex formation between calcium and d-saccharate ions, for which, at 25 °C, Kassoc = 1032 ± 80, ΔHassoc......° = -34 ± 6 kJ mol-1, and ΔSassoc° = -55 ± 9 J mol-1 K-1, were determined electrochemically. Calcium d-saccharate is sparingly soluble, with a solubility product, Ksp, of (6.17 ± 0.32) × 10-7 at 25 °C, only moderately increasing with the temperature: ΔHsol° = 48 ± 2 kJ mol-1, and ΔSassoc° = 42 ± 7 J mol-1...... K-1. Equilibria in supersaturated solutions of calcium d-saccharate seem only to adjust slowly, as seen from calcium activity measurements in calcium d-saccharate solutions made supersaturated by cooling. Solutions formed by isothermal dissolution of calcium d-gluconate in aqueous potassium d...

  5. In vitro study of novel gadolinium-loaded liposomes guided by GBI-10 aptamer for promising tumor targeting and tumor diagnosis by magnetic resonance imaging

    Directory of Open Access Journals (Sweden)

    Gu MJ

    2015-08-01

    Full Text Available Meng-Jie Gu,1,* Kun-Feng Li,1,* Lan-Xin Zhang,1 Huan Wang,1 Li-Si Liu,2 Zhuo-Zhao Zheng,2 Nan-Yin Han,1 Zhen-Jun Yang,1 Tian-Yuan Fan1 1State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, 2Department of Radiology, Peking University Third Hospital, Beijing, People’s Republic of China *These authors contributed equally to this work Abstract: Novel gadolinium-loaded liposomes guided by GBI-10 aptamer were developed and evaluated in vitro to enhance magnetic resonance imaging (MRI diagnosis of tumor. Nontargeted gadolinium-loaded liposomes were achieved by incorporating amphipathic material, Gd (III [N,N-bis-stearylamidomethyl-N'-amidomethyl] diethylenetriamine tetraacetic acid, into the liposome membrane using lipid film hydration method. GBI-10, as the targeting ligand, was then conjugated onto the liposome surface to get GBI-10-targeted gadolinium-loaded liposomes (GTLs. Both nontargeted gadolinium-loaded liposomes and GTLs displayed good dispersion stability, optimal size, and zeta potential for tumor targeting, as well as favorable imaging properties with enhanced relaxivity compared with a commercial MRI contrast agent (CA, gadopentetate dimeglumine. The use of GBI-10 aptamer in this liposomal system was intended to result in increased accumulation of gadolinium at the periphery of C6 glioma cells, where the targeting extracellular matrix protein tenascin-C is overexpressed. Increased cellular binding of GTLs to C6 cells was confirmed by confocal microscopy, flow cytometry, and MRI, demonstrating the promise of this novel delivery system as a carrier of MRI contrast agent for the diagnosis of tumor. These studies provide a new strategy furthering the development of nanomedicine for both diagnosis and therapy of tumor. Keywords: magnetic resonance imaging, gadolinium, liposomes, tenascin-C, GBI-10 aptamer, tumor targeting

  6. Activation of calcium-sensing receptor increases TRPC3 expression in rat cardiomyocytes

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Shan-Li [Department of Clinical Laboratory, The Second Affiliated Hospital of Harbin Medical University, Harbin 150086 (China); Sun, Ming-Rui [Department of Pharmacology, Qiqihaer Medical College, Qiqihaer 160001 (China); Li, Ting-Ting; Yin, Xin [Department of Clinical Laboratory, The Second Affiliated Hospital of Harbin Medical University, Harbin 150086 (China); Xu, Chang-Qing [Department of Pathophysiology, Harbin Medical University, Harbin 150086 (China); Sun, Yi-Hua, E-mail: syh200415@126.com [Department of Clinical Laboratory, The Second Affiliated Hospital of Harbin Medical University, Harbin 150086 (China)

    2011-03-11

    Research highlights: {yields} Calcium-sensing receptor (CaR) activation stimulates TRP channels. {yields} CaR promoted transient receptor potential C3 (TRPC3) expression. {yields} Adult rat ventricular myocytes display capacitative calcium entry (CCE), which was operated by TRPCs. {yields} TRPC channels activation induced by CaR activator sustained the increased [Ca{sup 2+}]{sub i} to evoke cardiomyocytes apoptosis. -- Abstract: Transient receptor potential (TRP) channels are expressed in cardiomyocytes, which gate a type of influx of extracellular calcium, the capacitative calcium entry. TRP channels play a role in mediating Ca{sup 2+} overload in the heart. Calcium-sensing receptors (CaR) are also expressed in rat cardiac tissue and promote the apoptosis of cardiomyocytes by Ca{sup 2+} overload. However, data about the link between CaR and TRP channels in rat heart are few. In this study, reverse transcriptase polymerase chain reaction (RT-PCR) and Western blotting were used to examine the expression of the TRP canonical proteins TRPC1 and TRPC3 in adult and neonatal rat cardiomyocytes. Laser scan confocal microscopy was used to detect intracellular [Ca{sup 2+}]{sub i} levels in isolated adult rat ventricular myocytes. The results showed that, in adult rat cardiomyocytes, the depletion of Ca{sup 2+} stores in the endoplasmic/sarcoplasmic reticulum (ER/SR) by thapsigargin induced a transient increase in [Ca{sup 2+}]{sub i} in the absence of [Ca{sup 2+}]{sub o} and the subsequent restoration of [Ca{sup 2+}]{sub o} sustained the increased [Ca{sup 2+}]{sub i} for a few minutes, whereas, the persisting elevation of [Ca{sup 2+}]{sub i} was reduced in the presence of the TRPC inhibitor SKF96365. The stimulation of CaR by its activator gadolinium chloride (GdCl{sub 3}) or spermine also resulted in the same effect and the duration of [Ca{sup 2+}]{sub i} increase was also shortened in the absence of [Ca{sup 2+}]{sub o}. In adult and neonatal rat cardiomyocytes, GdCl{sub 3

  7. Estimation of presynaptic calcium currents and endogenous calcium buffers at the frog neuromuscular junction with two different calcium fluorescent dyes.

    Science.gov (United States)

    Samigullin, Dmitry; Fatikhov, Nijaz; Khaziev, Eduard; Skorinkin, Andrey; Nikolsky, Eugeny; Bukharaeva, Ellya

    2014-01-01

    At the frog neuromuscular junction, under physiological conditions, the direct measurement of calcium currents and of the concentration of intracellular calcium buffers-which determine the kinetics of calcium concentration and neurotransmitter release from the nerve terminal-has hitherto been technically impossible. With the aim of quantifying both Ca(2+) currents and the intracellular calcium buffers, we measured fluorescence signals from nerve terminals loaded with the low-affinity calcium dye Magnesium Green or the high-affinity dye Oregon Green BAPTA-1, simultaneously with microelectrode recordings of nerve-action potentials and end-plate currents. The action-potential-induced fluorescence signals in the nerve terminals developed much more slowly than the postsynaptic response. To clarify the reasons for this observation and to define a spatiotemporal profile of intracellular calcium and of the concentration of mobile and fixed calcium buffers, mathematical modeling was employed. The best approximations of the experimental calcium transients for both calcium dyes were obtained when the calcium current had an amplitude of 1.6 ± 0.08 pA and a half-decay time of 1.2 ± 0.06 ms, and when the concentrations of mobile and fixed calcium buffers were 250 ± 13 μM and 8 ± 0.4 mM, respectively. High concentrations of endogenous buffers define the time course of calcium transients after an action potential in the axoplasm, and may modify synaptic plasticity.

  8. High-pressure liquid chromatography of trace elements: Determination of terbium in terbium doped gadolinium oxide sulphide phosphors

    International Nuclear Information System (INIS)

    Mazzucotelli, A.; Dadone, A.; Frache, R.; Baffi, F.; Genoa Univ.

    1982-01-01

    A detailed study of isocratic and gradient elution separations of lanthanides has been carried out. Analyses of industrially and scientifically interesting products such as luminescent phosphors have been carried out by gradient elution with DL-2-hydroxyisobutyric acid. The determination of small amounts of terbium in gadolinium oxide sulphide phosphors is described in which an HCl solution was eluted through a stainless steel column packed with microparticulate silica, with bonded cation-exchange groups. Complete separation of gadolinium and terbium is achieved. Detection is with a variable wavelength detector following post-column complex formation with 4-(2-pyridylazo)-resorcinol monosodium salt. Results obtained on test solutions show good reproducilbity and sensitivtiy and the method may be considered sufficiently reliable to be used in routine quality control procedures. (orig.)

  9. Importance of timing of post-contrast MRI in rheumatoid arthritis: what happens during the first 60 minutes after IV gadolinium-DTPA?

    DEFF Research Database (Denmark)

    Østergaard, Mikkel; Klarlund, Mette

    2001-01-01

    compromises the differentiation of synovium from joint fluid. OBJECTIVE: To determine the time period after IV MRI contrast (gadolinium-DTPA (Gd)) injection in which synovial membrane volume determination is reliable. METHODS: MRI of five RA knees with clinical synovitis was carried out, with axial, T(1...... threshold. Thereafter, the measured volumes remained practically unchanged. CONCLUSION: This study suggests that MR image acquisition in arthritic knee joints should be performed within the initial approximately 10 minutes after gadolinium contrast injection to achieve the most accurate distinction between...

  10. Research of calcium oxide hydration in calcium nitrate solutions

    Directory of Open Access Journals (Sweden)

    M.A. Oliynyk

    2016-09-01

    Full Text Available Mineral fertilizers are one of the important factors of agriculture intensification and increasing of food products quantity. The volume of fertilizers production and its domestic consumption in Ukraine indicate that nitrogen fertilizer using only comes nearer to the required number of science-based. One of the most widespread artificial fertilizers is the calcium nitrate. Aim: The aim is to study and theoretically substantiate the processes occurring in the preparation of suspensions of calcium hydroxide Са(ОН2 in solution of calcium nitrate Ca(NО32. Materials and Methods: The technical calcium oxide (quicklime DSTU BV.2.7-90-99, solutions of calcium nitrate of 15, 20, 25, 30, 35 and 40% Ca(NО32 concentrations were used in the work. The content of lime in the preparation of a suspension in the solution changed (in terms of calcium oxide CaO from 150 g/dm3 to the maximum possible. Each of these solutions saturated at 40°С in lime to maximum concentration. Suitable for use in these experiments and in the technology of calcium nitrate obtaining are considered the solutions (suspensions that within 12 hours did not lose their mobility (transportability. Results: The experimental results show that increasing of the concentration of calcium nitrate in solution within the range 15...40%, the amount of lime that you can put into the solution without loss of transportability decreases. Further increasing of lime quantity in solutions concentrations causes to its solidifying, loss of mobility (transportability. Calculations showed that in the presence of calcium nitrate the solubility of Са(ОН2 is reduced nearly by order that can lead to the formation of calcium oxide CaO the solid phase Са(ОН2 on the surface, which also can form hydrogen bonds with the components of the solution. As the probability of formation of hydrogen bonds in solutions is high, there is a possibility of formation of clusters.

  11. Evaluation of the in vitro stability of gadolinium (III) polyoxometalates

    International Nuclear Information System (INIS)

    Crooks, William J.; Choppin, Gregory R.; Rogers, Buck E.; Welch, Michael

    1997-01-01

    The gadolinium chelates of lacunary polyoxometalates were evaluated for in vitro stability against rat serum, diethylenetriaminepentaacetic acid (DTPA), endogenous metal cations, and DTPA-doped rat serum. The chelates dissociated rapidly in rat serum. Challenges by DTPA gave relatively slower dissociation rates, whereas challenges by endogenous metal cations (Fe(III), Zn(II), and Cu(II)) occurred at a rate comparable to the serum challenge, suggesting the instability in serum is due to a transmetalation mechanism. Challenges by DTPA-doped serum gave slower rates of dissociation than in native serum, verifying the transmetalation mechanism

  12. Gadolinium-DTPA in MR imaging of intracranial and spinal tumors

    International Nuclear Information System (INIS)

    Kakitsubata, Yousuke; Harada, Kuniko; Mori, Yukiko; Kihara, Yasushi; Kakitsubata, Sachiko; Watanabe, Katsushi

    1988-01-01

    Magnetic resonance(MR) imaging was performed on 23 patients with intracranial and spinal tumors, before and after intravenous administration of gadolinium-DTPA (Gd-DTPA). Contrast enhancement was observed in 20 of the 23 tumors. Glioblastomas, intracranial metastases, meningiomas and hemangioblastomas were markedly enhanced by Gd-DTPA. In precontrast scan, tumor delineation was best shown by T 2 weighted images. But T 1 weighted images showed better tumor delineation than T 2 weighted images after administration of Gd-DTPA. No side effects were encountered following administration of Gd-DTPA. (author)

  13. Production of precipitated calcium carbonate from calcium silicates and carbon dioxide

    International Nuclear Information System (INIS)

    Teir, Sebastian; Eloneva, Sanni; Zevenhoven, Ron

    2005-01-01

    The possibilities for reducing carbon dioxide emissions from the pulp and paper industry by calcium carbonation are presented. The current precipitated calcium carbonate (PCC) production uses mined, crushed calcium carbonate as raw materials. If calcium silicates were used instead, carbon dioxide emissions from the calcination of carbonates would be eliminated. In Finland, there could, thus, be a potential for eliminating 200 kt of carbon dioxide emissions per year, considering only the PCC used in the pulp and paper industry. A preliminary investigation of the feasibility to produce PCC from calcium silicates and the potential to replace calcium carbonate as the raw material was made. Calcium carbonate can be manufactured from calcium silicates by various methods, but only a few have been experimentally verified. The possibility and feasibility of these methods as a replacement for the current PCC production process was studied by thermodynamic equilibrium calculations using HSC software and process modelling using Aspen Plus[reg]. The results from the process modelling showed that a process that uses acetic acid for extraction of the calcium ions is a high potential option for sequestering carbon dioxide by mineral carbonation. The main obstacle seems to be the limited availability and relatively high price of wollastonite, which is a mineral with high calcium silicate content. An alternative is to use the more common, but also more complex, basalt rock instead

  14. Estimation of presynaptic calcium currents and endogenous calcium buffers at the frog neuromuscular junction with two different calcium fluorescent dyes

    Directory of Open Access Journals (Sweden)

    Dmitry eSamigullin

    2015-01-01

    Full Text Available At the frog neuromuscular junction, under physiological conditions, the direct measurement of calcium currents and of the concentration of intracellular calcium buffers—which determine the kinetics of calcium concentration and neurotransmitter release from the nerve terminal—has hitherto been technically impossible. With the aim of quantifying both Ca2+ currents and the intracellular calcium buffers, we measured fluorescence signals from nerve terminals loaded with the low-affinity calcium dye Magnesium Green or the high-affinity dye Oregon Green BAPTA-1, simultaneously with microelectrode recordings of nerve-action potentials and end-plate currents. The action-potential-induced fluorescence signals in the nerve terminals developed much more slowly than the postsynaptic response. To clarify the reasons for this observation and to define a spatiotemporal profile of intracellular calcium and of the concentration of mobile and fixed calcium buffers, mathematical modeling was employed. The best approximations of the experimental calcium transients for both calcium dyes were obtained when the calcium current had an amplitude of 1.6 ± 0.08 рА and a half-decay time of 1.2 ± 0.06 ms, and when the concentrations of mobile and fixed calcium buffers were 250 ± 13 µM and 8 ± 0.4 mM, respectively. High concentrations of endogenous buffers define the time course of calcium transients after an action potential in the axoplasm, and may modify synaptic plasticity.

  15. Calcium electroporation in three cell lines; a comparison of bleomycin and calcium, calcium compounds, and pulsing conditions

    DEFF Research Database (Denmark)

    Frandsen, Stine Krog; Gissel, Hanne; Hojman, Pernille

    2013-01-01

    offers several advantages over standard treatment options: calcium is inexpensive and may readily be applied without special precautions, as is the case with cytostatic drugs. Therefore, details on the use of calcium electroporation are essential for carrying out clinical trials comparing calcium...

  16. Transcellular transport of calcium

    Energy Technology Data Exchange (ETDEWEB)

    Terepka, A R; Coleman, J R; Armbrecht, H J; Gunter, T E

    1976-01-01

    Studies of two calcium transporting epithelia, embryonic chick chorioallantoic membrane and the small intestine of rat and chick, have strongly suggested that the transfer of calcium across a cell involves processes distinctly different from intracellular calcium ion regulation. In the proposed model, transcellular calcium transport is considered as a specialized process developed only by certain cells in those tissues charged with bulk transfer of calcium. The overall effect of the endocytotic mechanism is bulk calcium movement across a cell, protection of mitochondria from exposure to high concentrations of calcium, and the avoidance of wide and potentially toxic fluctuations in cytosol ionic calcium levels. (MFB)

  17. Gadolinium enhanced cardiovascular magnetic resonance in Anderson-Fabry disease. Evidence for a disease specific abnormality of the myocardial interstitium.

    Science.gov (United States)

    Moon, James C C; Sachdev, Bhavesh; Elkington, Andrew G; McKenna, William J; Mehta, Atul; Pennell, Dudley J; Leed, Philip J; Elliott, Perry M

    2003-12-01

    Anderson-Fabry Disease (AFD), an X-linked disorder of sphingolipid metabolism, is a cause of idiopathic left ventricular hypertrophy but the mechanism of hypertrophy is poorly understood. Gadolinium enhanced cardiovascular magnetic resonance can detect focal myocardial fibrosis. We hypothesised that hyperenhancement would be present in AFD. Eighteen males (mean 43+/-14 years) and eight female heterozygotes (mean 48+/-12 years) with AFD underwent cine and late gadolinium cardiovascular magnetic resonance. Nine male (50%) had myocardial hyperenhancement ranging from 3.4% to 20.6% (mean 7.7+/-5.7%) of total myocardium; in males, percentage hyperenhancement related to LV mass index (r=0.78, P=0.0002) but not to ejection fraction or left ventricular volumes. Lesser hyperenhancement was also found in four (50%) heterozygous females (mean 4.6%). In 12 (92%) patients with abnormal gadolinium uptake, hyperenhancement occurred in the basal infero-lateral wall where, unlike myocardial infarction, it was not sub-endocardial. In two male patients with severe LVH (left ventricular hypertrophy) and systolic impairment there was additional hyperenhancement in other myocardial segments. These observations suggests that myocardial fibrosis occurs in AFD and may contribute to the hypertrophy and the natural history of the disease.

  18. 3D gadolinium-enhanced MRI venography: Evaluation of central chest veins and impact on patient management

    International Nuclear Information System (INIS)

    Oxtoby, J.W.; Widjaja, E.; Gibson, K.M.; Uzoka, K.

    2001-01-01

    AIM: To assess the value of a simplified 3D gadolinium-enhanced magnetic resonance imaging (MRI) venography for central chest veins. MATERIALS AND METHODS: In this retrospective study of 24 patients, the MRI findings and medical records were reviewed to determine whether MRI results correlated with subsequent findings, and to determine the effect on clinical management. 3D steady state gradient-echo sequence, fast imaging with steady state precession (FISP), was used. We employed a simplified protocol not requiring bolus timing or subtraction to achieve rapid data acquisition and hence good compliance in this group of frail patients. Following intravenous administration of a bolus of gadolinium, two acquisitions were obtained in order to ensure adequate opacification of all veins. Individual partitions and maximum intensity projections were then analysed to determine whether the veins were patent, stenosed or occluded. RESULTS: The indications for MRI were to assess the patency of central veins for the purpose of cannulation or arteriovenous fistula formation in 17 patients. Out of the 12 patients who proceeded to an intervention, MRI venography successfully predicted an appropriate site in 10 patients. In the remaining seven patients, MRI venography was valuable in confirming or excluding the clinical suspicion of central venous thrombosis and directly influenced the management in five patients. CONCLUSION: 3D gadolinium-enhanced MRI venography is a valuable means of providing a global representation of the central venous system and guiding subsequent central venous cannulation. Oxtoby, J.W. et al. (2001)

  19. Demonstration of multiple neurofibromas in gadolinium-DTPA enhanced MRI - a case report

    International Nuclear Information System (INIS)

    Kaminsky, S.; Schulz, B.

    1988-01-01

    Although magnetic resonance imaging has a high sensitivity for cerebral and spinal tumors, demonstration of small lesions can be difficult. In a patient with multiple extra- and intraspinal tumors due to neurofibromatosis generalisata, the use of the MRI contrast agent gadolinium-DTPA resulted in a better differentiation especially of small lesions. High tumor contrast facilitated a safe localisation of the widespread disease using a fast imaging sequence (FLASH). (orig.) [de

  20. Switching of the polarization of ferroelectric-ferroelastic gadolinium molybdate in a magnetic field

    Science.gov (United States)

    Yakushkin, E. D.

    2017-10-01

    A change in the character of the electric switching of polydomain ferroelectric-ferroelastic gadolinium molybdate in an external magnetic field has been detected. This change has been attributed to a magnetically stimulated increase in the pinning of domain walls. Under certain conditions, the loop of switchable polarization is degenerated into an ellipse characteristic of a linear insulator with leakage current.

  1. Calcium hydroxide poisoning

    Science.gov (United States)

    Hydrate - calcium; Lime milk; Slaked lime ... Calcium hydroxide ... These products contain calcium hydroxide: Cement Limewater Many industrial solvents and cleaners (hundreds to thousands of construction products, flooring strippers, brick cleaners, cement ...

  2. Study for the determination of samarium, europium,terbium, dysprosium and yttrium in gadolinium oxide matrix by means of atomic absorption spectrophotometry using a graphite furnace

    International Nuclear Information System (INIS)

    Caires, A.C.F.

    1985-01-01

    A study for determination of samarium, europium, terbium, dysprosium and yttrium in a gadolinium oxide matrix by atomic absorption spectrophotometry using a graphite furnace is presented. The best charrring and atomization conditions were estabilished for each element, the most convenient ressonance lines being selected as well. The study was carried out for the mentioned lanthanides both when pure and when in binary mixtures with gadolinium, besides those where all for them were together with gadolinium. The determination limits for pure lanthanides were found to be between 1.3 and 9.6 ng assuming a 20% relative standard deviation as acceptable. The detection limits were in the range 0.51 and 7.5 ng, assuming as positive any answer higher than twofold the standard deviation. (author) [pt

  3. Legg-Perthes-Calve disease: staging by MRI using gadolinium

    Energy Technology Data Exchange (ETDEWEB)

    Ducou le Pointe, H. (Dept. of Pediatric Radiology, Hopital d' Enfants Armand-Trousseau, 75 - Paris (France)); Haddad, S. (Dept. of Pediatric Radiology, Hopital d' Enfants Armand-Trousseau, 75 - Paris (France)); Silberman, B. (Dept. of Pediatric Radiology, Hopital d' Enfants Armand-Trousseau, 75 - Paris (France)); Filipe, G. (Dept. of Orthopedic Surgery, Hopital d' Enfants Armand-Trousseau, 75 - Paris (France)); Monroc, M. (Dept. of Pediatric Radiology, Hopital d' Enfants Armand-Trousseau, 75 - Paris (France)); Montagne, J.P. (Dept. of Pediatric Radiology, Hopital d' Enfants Armand-Trousseau, 75 - Paris (France))

    1994-04-01

    Twenty-one patients (26 hips) with typical signs of Legg-Perthes-Calve (LPC) disease on plain radiographs were explored by MRI. Patients were imaged with a 0.5 T MR unit. Gadolinium-enhanced spinecho MR images were obtained after nonenhanced T1-weighted (spin-echo) and T2[sup *]-weighted (gradient-echo) images. Four different areas were identified in the femoral epiphysis (necrosis, regenerative, cartilaginous and normal fatty bone tissue). The histological evolution of LPC is well described by Catterall and others. Comparing their descriptions with out MR findings, we suggest classification ofLPC into five phases: necrosis: regeneration, reconstruction, reossification and sequelae. (orig.)

  4. Kinetics of calcium sulfoaluminate formation from tricalcium aluminate, calcium sulfate and calcium oxide

    International Nuclear Information System (INIS)

    Li, Xuerun; Zhang, Yu; Shen, Xiaodong; Wang, Qianqian; Pan, Zhigang

    2014-01-01

    The formation kinetics of tricalcium aluminate (C 3 A) and calcium sulfate yielding calcium sulfoaluminate (C 4 A 3 $) and the decomposition kinetics of calcium sulfoaluminate were investigated by sintering a mixture of synthetic C 3 A and gypsum. The quantitative analysis of the phase composition was performed by X-ray powder diffraction analysis using the Rietveld method. The results showed that the formation reaction 3Ca 3 Al 2 O 6 + CaSO 4 → Ca 4 Al 6 O 12 (SO 4 ) + 6CaO was the primary reaction 4 Al 6 O 12 (SO 4 ) + 10CaO → 6Ca 3 Al 2 O 6 + 2SO 2 ↑ + O 2 ↑ primarily occurred beyond 1350 °C with an activation energy of 792 ± 64 kJ/mol. The optimal formation region for C 4 A 3 $ was from 1150 °C to 1350 °C and from 6 h to 1 h, which could provide useful information on the formation of C 4 A 3 $ containing clinkers. The Jander diffusion model was feasible for the formation and decomposition of calcium sulfoaluminate. Ca 2+ and SO 4 2− were the diffusive species in both the formation and decomposition reactions. -- Highlights: •Formation and decomposition of calcium sulphoaluminate were studied. •Decomposition of calcium sulphoaluminate combined CaO and yielded C 3 A. •Activation energy for formation was 231 ± 42 kJ/mol. •Activation energy for decomposition was 792 ± 64 kJ/mol. •Both the formation and decomposition were controlled by diffusion

  5. Why Calcium? How Calcium Became the Best Communicator*

    Science.gov (United States)

    Carafoli, Ernesto; Krebs, Joachim

    2016-01-01

    Calcium carries messages to virtually all important functions of cells. Although it was already active in unicellular organisms, its role became universally important after the transition to multicellular life. In this Minireview, we explore how calcium ended up in this privileged position. Most likely its unique coordination chemistry was a decisive factor as it makes its binding by complex molecules particularly easy even in the presence of large excesses of other cations, e.g. magnesium. Its free concentration within cells can thus be maintained at the very low levels demanded by the signaling function. A large cadre of proteins has evolved to bind or transport calcium. They all contribute to buffer it within cells, but a number of them also decode its message for the benefit of the target. The most important of these “calcium sensors” are the EF-hand proteins. Calcium is an ambivalent messenger. Although essential to the correct functioning of cell processes, if not carefully controlled spatially and temporally within cells, it generates variously severe cell dysfunctions, and even cell death. PMID:27462077

  6. Neurosarcoidosis--demonstration of meningeal disease by gadolinium enhanced magnetic resonance imaging.

    Science.gov (United States)

    Khaw, K T; Manji, H; Britton, J; Schon, F

    1991-01-01

    Arriving at a firm diagnosis of neurosarcoidosis continues to pose serious problems, particularly when evidence of granulomatous disease outside the nervous system is lacking. The commonest mode of presentation of neurosarcoidosis is with cranial nerve palsies. Two cases of presumed neurosarcoidosis with cranial nerve palsies showed clear evidence of focal meningeal disease on gadolinium-DTPA enhanced MRI brain scans. Although not specific for sarcoidosis, this technique may be very useful in aiding the diagnosis in suspected cases. Images PMID:1880510

  7. Codissolution of calcium hydrogenphosphate and sodium hydrogencitrate in water. Spontaneous supersaturation of calcium citrate increasing calcium bioavailability

    DEFF Research Database (Denmark)

    Hedegaard, Martina Vavrusova; Danielsen, Bente Pia; Garcia, André Castilho

    2018-01-01

    The sparingly soluble calcium hydrogenphosphate dihydrate, co-dissolving in water during dissolution of freely soluble sodium hydrogencitrate sesquihydrate as caused by proton transfer from hydrogencitrate to hydrogenphosphate, was found to form homogenous solutions supersaturated by a factor up...... to 8 in calcium citrate tetrahydrate. A critical hydrogencitrate concentration for formation of homogeneous solutions was found to depend linearly on dissolved calcium hydrogenphosphate: [HCitr2-] = 14[CaHPO4] - 0.05 at 25 °C. The lag phase for precipitation of calcium citrate tetrahydrate......, as identified from FT-IR spectra, from these spontaneously formed supersaturated solutions was several hours, and the time to reach solubility equilibrium was several days. Initial calcium ion activity was found to be almost independent of the degree of supersaturation as determined electrochemically...

  8. Isotope shift studies in gadolinium spectra

    International Nuclear Information System (INIS)

    Ahmad, S.A.; Saksena, G.D.; Venugopalan, A.

    1975-01-01

    Isotope shift studies have been carried out in the gadolinium spectrum using a recording Fabry-Perot spectrometer and gadolinium samples enriched in 156 Gd and 160 Gd isotopes. The source used is a liquid-nitrogen-cooled hollow cathode with Ne as the carrier gas and operating at about 30 mA. Isotope shifts Δsigma (156-160) have been recorded in 350 transitions of Gd I and Gd II. In the case of the Gd I spectrum, the transitions studied presently involve almost all the reported configurations assigned to the energy levels of Gd I. The odd configurations are 4f 7 5d6s 2 , 4f 7 5d 2 6s, 4f 7 5d 3 , 4f 8 6s6p, 4f 7 5d6s7s and 4f 7 6s 2 6p, and the even ones are 4f 8 6s 2 , 4f 7 5d6s6p, 4f 7 6s 2 6p, 4f 8 5d6s and 4f 7 5d 2 6p. In the case of the Gd II spectrum isotope shifts in the lines of the newly classified transition 4f 8 6s - 4f 8 6p have been studied and isotope shift ΔT (156-160) 87 mK has been obtained for the 4f 8 6s configuration. The other transitions of Gd II involve the odd configurations 4f 7 5d6s, 4f 7 6s 2 , 4f 7 5d 2 and 4f 8 6p and the even ones 4f 7 6s6p, 4f 8 5d, 4f 7 5d6p and 4f 8 6p. The ΔT (156-160) of a large number of odd and even levels of Gd I and Gd II have been evaluated. Electronic configurations have been suggested for a number of energy levels and configuration mixing has been pointed out in certain cases. A number of hitherto unreported transitions have been found and using a monoisotopic sample of Gd, that is 160 Gd, their separations from the closest listed transitions have been measured. (author)

  9. Calcium blood test

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/003477.htm Calcium blood test To use the sharing features on this page, please enable JavaScript. The calcium blood test measures the level of calcium in the blood. ...

  10. High Relaxivity Gadolinium Hydroxypyridonate-Viral Capsid Conjugates: Nano-sized MRI Contrast Agents

    Energy Technology Data Exchange (ETDEWEB)

    Meux, Susan C.; Datta, Ankona; Hooker, Jacob M.; Botta, Mauro; Francis, Matthew B.; Aime, Silvio; Raymond, Kenneth N.

    2007-08-29

    High relaxivity macromolecular contrast agents based on the conjugation of gadolinium chelates to the interior and exterior surfaces of MS2 viral capsids are assessed. The proton nuclear magnetic relaxation dispersion (NMRD) profiles of the conjugates show up to a five-fold increase in relaxivity, leading to a peak relaxivity (per Gd{sup 3+} ion) of 41.6 mM{sup -1}s{sup -1} at 30 MHz for the internally modified capsids. Modification of the exterior was achieved through conjugation to flexible lysines, while internal modification was accomplished by conjugation to relatively rigid tyrosines. Higher relaxivities were obtained for the internally modified capsids, showing that (1) there is facile diffusion of water to the interior of capsids and (2) the rigidity of the linker attaching the complex to the macromolecule is important for obtaining high relaxivity enhancements. The viral capsid conjugated gadolinium hydroxypyridonate complexes appear to possess two inner-sphere water molecules (q = 2) and the NMRD fittings highlight the differences in the local motion for the internal ({tau}{sub RI} = 440 ps) and external ({tau}{sub RI} = 310 ps) conjugates. These results indicate that there are significant advantages of using the internal surface of the capsids for contrast agent attachment, leaving the exterior surface available for the installation of tissue targeting groups.

  11. Calcium carbonate overdose

    Science.gov (United States)

    Tums overdose; Calcium overdose ... Calcium carbonate can be dangerous in large amounts. ... Products that contain calcium carbonate are certain: Antacids (Tums, Chooz) Mineral supplements Hand lotions Vitamin and mineral supplements Other products may also contain ...

  12. Gadolinium(III Ion-Selective Electrode Based on 3-Methyl-1H-1,2,4-triazole-5-thiol

    Directory of Open Access Journals (Sweden)

    Hassan Ali Zamani

    2012-01-01

    Full Text Available The 3-methyl-1H-1,2,4-triazole-5-thiol (MTH was used as a suitable ionophore for fabrication of a new gadolinium(III ion selective potentiometric sensor. Nitrobenzene (NB was used as plasticizing solvent mediator and sodium tetraphenyl borate (NaTPB as an anion excluder. It displays a Nernstian response (19.8± 0.4 mV/decade in the concentration range of 1.0×10-7 to 1.0×10-2 M with the detection limit of 7.3×10-8 M. The sensor has a very short response time (<10s and can be used the pH range of 2.9-8.4. electrode was successfully applied as an indicator for gadolinium determination in titration with EDTA.

  13. Detection of liver lesions with gadolinium-enhanced VIBE sequence in comparison with SPIO-enhanced MRI; Detektion von Leberlaesionen mit der Gadolinium-verstaerkten VIBE-Sequenz im Vergleich zur SPIO-verstaerkten MRT

    Energy Technology Data Exchange (ETDEWEB)

    Heim, P.; Steiner, P.; Dieckmann, C.; Adam, G. [Universitaetsklinikum Hamburg-Eppendorf (Germany). Klinik und Poliklinik fuer Diagnostische und Interventionelle Radiologie; Schoder, V. [Universitaetsklinikum Hamburg-Eppendorf (Germany). Inst. fuer Medizinische Biometrie und Epidemiologie; Kuhlencordt, R. [Universitaetsklinikum Hamburg-Eppendorf (Germany). Klinik und Poliklinik fuer Allgemein-, Viszeral-, und Thoraxchirurgie

    2003-10-01

    Purpose: Detection of malignant liver lesions with gadolinium-enhanced volumetric interpolated breath-hold examination (VIBE) in comparison with SPIO-enhanced MRT (four different SPIO-enhanced T2w sequences) and histological and imaging follow-up in non-cirrhotic livers at 1.5 T. Patients and methods: Twenty-two patients with suspected focal liver lesions prospectively underwent a gadolinium-enhanced 3D VIBE. Four T2w sequences (HASTE sequence, fast spin-echo-sequence with and without fat-saturation, FLASH 2D gradient echo-sequence) after administration of superparamagnetic iron oxide (SPIO) served as gold standard combined with histological work-up in 17 patients and histological and imaging follow-up in five patients. The image quality was evaluated and the detectability of intrahepatic lesions was rated by the alternative free-response receiver operating characteristic (AFROC) analysis. In addition, the contrast-to-noise ration was compared. Results: Altogether 49 malignant and 35 benign liver lesions were found. Concerning the image quality, VIBE turned out to be of slightly poorer image quality than the SPIO-enhanced examination with HASTE sequence (4.95 vs. 5.0). The fast spin-echo-sequence without fat-saturation demonstrated the highest contrast-to-noise ratio. All sequences showed a comparable certainty in detecting lesion (area under the curve 0.68-0.74) and identifying malignant liver lesions. Conclusions: Despite the small number of patients, VIBE seems to be a comparable, inexpensive and fast method in diagnosing malignant liver lesions. (orig.) [German] Ziel: Detektion maligner Leberlaesionen mit der Gadolinium-verstaerkten 3D-Gradientenecho-Sequenz in Atemanhaltetechnik (VIBE-Sequenz) im Vergleich mit der SPIO-verstaerkten MRT (vier verschiedene SPIO-verstaerkte T2-gew. Sequenzen) sowie histologischen und bildgebenden (Verlaufs-) Untersuchungen in nicht-zirrhotischen Lebern bei 1,5 T. Patienten und Methoden: 22 Patienten mit Verdacht auf maligne

  14. Differentiation of recurrent breast cancer from radiation fibrosis with dynamic gadolinium-enhanced MR imaging

    International Nuclear Information System (INIS)

    Dao, T.H.; Campana, F.; Fourquet, A.; Rahmouni, A.

    1991-01-01

    This paper assesses the ability of dynamic gadolinium-enhanced MR imaging to differentiate radiation fibrosis from tumor recurrence of breast cancer after conservative treatment. Twenty-five women with previous breast cancer treated with radiation therapy underwent MR imaging examination. Tumor recurrence was suspected on palpation of masses (18 cases) or at mammography (7 cases). The MR imaging protocol was performed on a 0.5-T imager with a breast coil and included T1 and T2 spin-echo, short To inversion recovery (STIR), and dynamic gadolinium-enhanced T1-weighted sequenced to evaluate the hemokinetics of the lesion. Ratios of signal intensity of suspected lesions to that of fat, surrounding breast gland, and background noise were calculated. Percutaneous biopsies were performed in all cases after MR imaging. Curves of signal-to-noise ratio of recurrences (5 cases) showed an early enhancement within the first minutes after injection, although localized fibrosis (20 cases) was not significantly enhanced. T2 and STIR sequences were not contributive in differentiating fibrosis from tumor recurrence

  15. Rapid MR measurements of contrast medium dilution kinetics (gadolinium-DTPA) in a flow phantom

    International Nuclear Information System (INIS)

    Boeck, J.C.; Sander, B.; Frank, J.; Schoerner, W.

    1991-01-01

    We studied first-pass MRI-contrast dilution to compute flow and volume of distribution in a realistic flow phantom. Pulsatile flow was provided by a one-chamber artificial heart. Physiological stroke volume, rate, pressure, and flow were adjustable. An elastic tube with dimensions similar to that of the human aorta was imaged at a rate of 2.4 Hz. After contrast injection, an initial increase in signal intensity was followed by a decrease. Signal-intensity-time plots demonstrated slightly skewed curves as expected from dispersion theory. After calibration at different gadolinium-DTPA concentrations, signal intensities were converted into true gadolinium concentrations, and flow was calculated from the concentration-time curves. Flow was varied between 2.5 and 10.0 l/min and a significant correlation was found between the MRI-estimate and true flow. Volume of distribution between injection and detection site was reliably estimated. This study demonstrates rapid 2-D imaging of a paramagnetic contrast bolus in a realistic flow phantom. Reliable estimates of flow and volume are obtained. (orig.) [de

  16. Calcium: the molecular basis of calcium action in biology and medicine

    National Research Council Canada - National Science Library

    Pochet, Roland; Donato, Rosario

    2000-01-01

    ... of Calcium Calcium Signalling in Excitable Cells Ca2+ Release in Muscle Cells by N. Macrez and J. Mironneau Calcium Signalling in Neurons Exemplified by Rat Sympathetic Ganglion Cells by S.J. M...

  17. Calcium source (image)

    Science.gov (United States)

    Getting enough calcium to keep bones from thinning throughout a person's life may be made more difficult if that person has ... as a tendency toward kidney stones, for avoiding calcium-rich food sources. Calcium deficiency also effects the ...

  18. Use of gadolinium chelate to confirm epidural needle placement in patients with an iodinated contrast reaction

    International Nuclear Information System (INIS)

    Shetty, Sanjay K.; Nelson, Erik N.; Lawrimore, Tara M.; Palmer, William E.

    2007-01-01

    When performing epidural steroid injections for the management of chronic back pain, imaging guidance and a limited epidurogram improve accuracy of needle placement and ensure appropriate delivery of the injectate into the epidural space. We describe our experience using a gadolinium chelate as an alternative contrast agent for limited epidurography in patients with a history of an iodinated contrast reaction. Thirty-eight of 2,067 (1.8%) epidural steroid injections performed in our department over a 25-month period (December 2003-January 2006) employed gadolinium. All injections were performed in the lumbar spine employing a paramedian interlaminar approach. Procedural notes and patient charts were reviewed to evaluate for immediate or delayed complications related to incorrect intrathecal or intravascular needle placement. A retrospective analysis of selected fluoroscopic spot images was performed to evaluate confidence of epidural needle placement; this analysis compared these spot images against those obtained from age- and gender-matched control patients in whom iodinated contrast was used to confirm needle placement. Real-time fluoroscopic guidance permitted confident visualization of an epidurogram at the time of procedure in all 38 cases as documented in the procedural report, and no procedure resulted in a complication due to incorrect needle placement. Retrospective review of fluoroscopic spot images revealed at least moderate confidence of epidural needle placement by both readers in 29/38 cases (76.3%). Fluoroscopic spot images obtained using gadolinium yielded significantly less confidence than images obtained in control patients whose procedures were performed using iodinated contrast (P < 0.01). However, operators were sufficiently confident in needle placement based on real-time fluoroscopic images (not available in our subsequent review) to inject anesthestic in all 38 cases, despite the immediate consequences that could result from intrathecal

  19. Use of gadolinium chelate to confirm epidural needle placement in patients with an iodinated contrast reaction

    Energy Technology Data Exchange (ETDEWEB)

    Shetty, Sanjay K. [Massachusetts General Hospital, Harvard Medical School, Division of Musculoskeletal Radiology, Department of Radiology, Boston, MA (United States); Beth Israel Deaconess Medical Center, Harvard Medical School, Department of Radiology, Boston, MA (United States); Nelson, Erik N.; Lawrimore, Tara M.; Palmer, William E. [Massachusetts General Hospital, Harvard Medical School, Division of Musculoskeletal Radiology, Department of Radiology, Boston, MA (United States)

    2007-04-15

    When performing epidural steroid injections for the management of chronic back pain, imaging guidance and a limited epidurogram improve accuracy of needle placement and ensure appropriate delivery of the injectate into the epidural space. We describe our experience using a gadolinium chelate as an alternative contrast agent for limited epidurography in patients with a history of an iodinated contrast reaction. Thirty-eight of 2,067 (1.8%) epidural steroid injections performed in our department over a 25-month period (December 2003-January 2006) employed gadolinium. All injections were performed in the lumbar spine employing a paramedian interlaminar approach. Procedural notes and patient charts were reviewed to evaluate for immediate or delayed complications related to incorrect intrathecal or intravascular needle placement. A retrospective analysis of selected fluoroscopic spot images was performed to evaluate confidence of epidural needle placement; this analysis compared these spot images against those obtained from age- and gender-matched control patients in whom iodinated contrast was used to confirm needle placement. Real-time fluoroscopic guidance permitted confident visualization of an epidurogram at the time of procedure in all 38 cases as documented in the procedural report, and no procedure resulted in a complication due to incorrect needle placement. Retrospective review of fluoroscopic spot images revealed at least moderate confidence of epidural needle placement by both readers in 29/38 cases (76.3%). Fluoroscopic spot images obtained using gadolinium yielded significantly less confidence than images obtained in control patients whose procedures were performed using iodinated contrast (P < 0.01). However, operators were sufficiently confident in needle placement based on real-time fluoroscopic images (not available in our subsequent review) to inject anesthestic in all 38 cases, despite the immediate consequences that could result from intrathecal

  20. Calcium ferrite formation from the thermolysis of calcium tris (maleato)

    Indian Academy of Sciences (India)

    For preparing calcium ferrite, calcium tris (maleato) ferrate(III) precursor was prepared by mixing aqueous solutions of iron(III) maleate, calcium maleate and maleic acid. Various physico-chemical techniques i.e. TG, DTG, DTA, Mössbauer, XRD, IR etc have been used to study the decomposition behaviour from ambient to ...

  1. A comparison of the COG and MCNP codes in computational neutron capture therapy modeling, Part II: gadolinium neutron capture therapy models and therapeutic effects.

    Science.gov (United States)

    Wangerin, K; Culbertson, C N; Jevremovic, T

    2005-08-01

    The goal of this study was to evaluate the COG Monte Carlo radiation transport code, developed and tested by Lawrence Livermore National Laboratory, for gadolinium neutron capture therapy (GdNCT) related modeling. The validity of COG NCT model has been established for this model, and here the calculation was extended to analyze the effect of various gadolinium concentrations on dose distribution and cell-kill effect of the GdNCT modality and to determine the optimum therapeutic conditions for treating brain cancers. The computational results were compared with the widely used MCNP code. The differences between the COG and MCNP predictions were generally small and suggest that the COG code can be applied to similar research problems in NCT. Results for this study also showed that a concentration of 100 ppm gadolinium in the tumor was most beneficial when using an epithermal neutron beam.

  2. A novel cryogenic magnetic refrigerant metal-organic framework based on 1D gadolinium(III) chain

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Qun; Li, Peng-Fei [Guangxi Key Laboratory of Electrochemical and Magneto-chemical Functional Materials, College of Chemistry and Bioengineering, Guilin University of Technology, Guilin, Guangxi 541004 (China); Zou, Zhi-Ming, E-mail: 2014005@glut.edu.cn [Guangxi Key Laboratory of Electrochemical and Magneto-chemical Functional Materials, College of Chemistry and Bioengineering, Guilin University of Technology, Guilin, Guangxi 541004 (China); Liu, Zheng [Guangxi Key Laboratory of Electrochemical and Magneto-chemical Functional Materials, College of Chemistry and Bioengineering, Guilin University of Technology, Guilin, Guangxi 541004 (China); Liu, Shu-Xia, E-mail: liusx@nenu.edu.cn [Key Laboratory of Polyoxometalate Science of Ministry of Education, College of Chemistry, Northeast Normal University, Changchun, Jilin 130024 (China)

    2017-02-15

    A metal-organic framework (MOF) based on gadolinium ion (Gd{sup 3+}) and tricarboxylate ligand, [Gd(BTPCA)(H{sub 2}O)]·2DMF·3H{sub 2}O (Gd-BTPCA) (H{sub 3}BTPCA =1,1′,1′-(benzene-1,3,5-triyl)tripiperidine-4-carboxylic acid; DMF=dimethylformamide), was synthesized and structurally characterized. The adjacent Gd{sup 3+} ions are intraconnected by the carboxylate groups of the BTPCA{sup 3-} ligands to form a 1D Gd{sup 3+} ion chain. The 1D Gd{sup 3+} ion chains are interconnected by the BTPCA{sup 3-} ligands, giving rise to a 3D framework with 1D open channel. The magnetic studies indicate that Gd-BTPCA exhibits weak ferromagnetic interactions, and acts as a cryogenic magnetic refrigerant having the magnetic entropy change (−ΔS{sub m}) of 20.40 J kg{sup −1} K{sup −1} for ΔH =7 T at 3 K. - Graphical abstract: A 1D gadolinium(III) chains-based metal-organic framework performed ferromagnetic coupling on the magnetic property. Magnetic investigation reveals that Gd-BTPCA exhibits the entropy change (−ΔS{sub m}) of 20.40 J kg{sup −1} K{sup −1} for ΔH =7 T at 3 K. - Highlights: • The MOF based on gadolinium ion and tricarboxylate ligand was synthesized. • This MOF is connected with 1D Gd{sup 3+} ions chain and the carboxylate groups of BTPCA{sup 3-} ligands. • The magnetic studies indicate that the MOF exhibits the weak ferromagnetic interactions. • Magnetic investigation reveals that the MOF exhibits the high entropy change.

  3. In vitro uptake of 153gadolinium and gadolinium complexes by hyaline articular cartilage

    International Nuclear Information System (INIS)

    Engel, A.; Fleischmann, D.; Hamilton, G.; Hajek, P.

    1990-01-01

    This in vitro study evaluated whether Gadolinium (Gd) penetrates into hyaline cartilage and would be incorporated into vital chondrocytes. Hyaline joint cartilage of rabbits was exposed to radioactive 153 GdCl 3 and to a radioactive 153 Gd-DTPA-BSA-complex (DTPA, diethylene-triaminepentaacetic acid; BSA, bovine serum albumine). In addition an exchange experiment with radioactive 153 GdCl 3 versus Gd-DTPA-di-N-methylglucamine (Magnevist) was performed. Incorporation of 153 GdCl 3 into neuroblastoma cells, connective tissue cells and chondrocytes was tested. The results showed that the depth and extent of incorporation of Gd depends on the molecular mass and time of exposure. 153 Gd-DTPA-BSA complexes exhibited an incorporation rate of maximal 11 per cent ± 2.8 per cent up to the middle third of the cartilage within 24 h with almost no incorporation (2 ± 1.9 per cent) for the deep layer. The exchange experiment revealed no uptake of Gd for the deep layer. The maximal incorporation rate of 153 GdCl 3 into vital chondrocytes was 6.3 per cent. These data indicate that under the condition of MR-arthrography, Gd-DTPA-di-N-methylglucamine will not be absorbed into the deep layers of hyaline cartilage and will not be incorporated into vital chondrocytes. (author). 8 refs.; 3 tabs

  4. Gadolinium chloride as a contrast agent for imaging wood composite components by magnetic resonance

    Science.gov (United States)

    Thomas L. Eberhardt; Chi-Leung So; Andrea Protti; Po-Wah So

    2009-01-01

    Although paramagnetic contrast agents have an established track record in medical uses of magnetic resonance imaging (MRI), only recently has a contrast agent been used for enhancing MRI images of solid wood specimens. Expanding on this concept, wood veneers were treated with a gadolinium-based contrast agent and used in a model system comprising three-ply plywood...

  5. The effect of habitat geology on calcium intake and calcium status of wild rodents.

    Science.gov (United States)

    Shore, R F; Balment, R J; Yalden, D W

    1991-12-01

    Calcium is essential for normal physiological function, reproduction and growth in mammals but its distribution in the natural environment is heterogeneous. Spatial variation in calcium soil content is especially marked in the Peak District, United Kingdom, where both calcium-rich limestone and calcium-poor gritstone rock types occur. Wood mice Apodemus sylvaticus (L) and bank voles Clethrionomys glareolus (Schreber 1780) from limestone areas had significantly higher calcium concentrations in stomach contents and in faeces compared with their counterparts from gritstone areas. Calcium status was assessed from serum calcium concentration, femur weight, ash content of the body, calcium concentration in the femur and body ash. There was no significant difference in serum calcium concentration, femur calcium concentration and body ash calcium concentration between animals from the limestone and the gritstone. However, on the limestone, bank voles, but not wood mice, had significantly heavier femora and a greater proportion of ash in the body compared with their gritstone counterparts.

  6. Calcium fertilization increases the concentration of calcium in sapwood and calcium oxalate in foliage of red spruce

    Science.gov (United States)

    Kevin T. Smith; Walter C. Shortle; Jon H. Connolly; Rakesh Minocha; Jody Jellison

    2009-01-01

    Calcium cycling plays a key role in the health and productivity of red spruce forests in the northeastern US. A portion of the flowpath of calcium within forests includes translocation as Ca2+ in sapwood and accumulation as crystals of calcium oxalate in foliage. Concentrations of Ca in these tree tissues have been used as markers of...

  7. Why Calcium? How Calcium Became the Best Communicator.

    Science.gov (United States)

    Carafoli, Ernesto; Krebs, Joachim

    2016-09-30

    Calcium carries messages to virtually all important functions of cells. Although it was already active in unicellular organisms, its role became universally important after the transition to multicellular life. In this Minireview, we explore how calcium ended up in this privileged position. Most likely its unique coordination chemistry was a decisive factor as it makes its binding by complex molecules particularly easy even in the presence of large excesses of other cations, e.g. magnesium. Its free concentration within cells can thus be maintained at the very low levels demanded by the signaling function. A large cadre of proteins has evolved to bind or transport calcium. They all contribute to buffer it within cells, but a number of them also decode its message for the benefit of the target. The most important of these "calcium sensors" are the EF-hand proteins. Calcium is an ambivalent messenger. Although essential to the correct functioning of cell processes, if not carefully controlled spatially and temporally within cells, it generates variously severe cell dysfunctions, and even cell death. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  8. High-resolution, three-step resonance ionization mass spectrometry of gadolinium

    International Nuclear Information System (INIS)

    Blaum, K.; Wendt, K.; Bushaw, B.A.; Noertershaeuser, W.

    2001-01-01

    High-resolution resonance ionization mass spectrometry has been used to measure triple-resonance autoionization (AI) spectra of gadolinium. Al resonances as narrow as 10 MHz have been observed and isotope shifts and hyperfine structure have been measured in selected AI states. The strongest AI state observed at 49663.576 cm-1 with a photoionization cross section of >3.6x10 -15 cm 2 was found to have an overall detection efficiency of >3x10 -5 , allowing application to a number of ultratrace determination problems. Analytical measurements with a diode-laser-based system have been successfully performed on bio-medical tissue samples

  9. Arterial double-contrast dual-energy MDCT: in-vivo rabbit atherosclerosis with iodinated nanoparticles and gadolinium agents

    Science.gov (United States)

    Carmi, Raz; Kafri, Galit; Altman, Ami; Goshen, Liran; Planer, David; Sosna, Jacob

    2010-03-01

    An in-vivo feasibility study of potentially improved atherosclerosis CT imaging is presented. By administration of two different contrast agents to rabbits with induced atherosclerotic plaques we aim at identifying both soft plaque and vessel lumen simultaneously. Initial injection of iodinated nanoparticle (INP) contrast agent (N1177 - Nanoscan Imaging), two to four hours before scan, leads to its later accumulation in macrophage-rich soft plaque, while a second gadolinium contrast agent (Magnevist) injected immediately prior to the scan blends with the aortic blood. The distinction between the two agents in a single scan is achieved with a double-layer dual-energy MDCT (Philips Healthcare) following material separation analysis using the reconstructed images of the different x-ray spectra. A single contrast agent injection scan, where only INP was injected two hours prior to the scan, was compared to a double-contrast scan taken four hours after INP injection and immediately after gadolinium injection. On the single contrast agent scan we observed along the aorta walls, localized iodine accumulation which can point on INP uptake by atherosclerotic plaque. In the double-contrast scan the gadolinium contributes a clearer depiction of the vessel lumen in addition to the lasting INP presence. The material separation shows a good correlation to the pathologies inferred from the conventional CT images of the two different scans while performing only a single scan prevents miss-registration problems and reduces radiation dose. These results suggest that a double-contrast dual-energy CT may be used for advanced clinical diagnostic applications.

  10. Optimizing the use of gadolinium as burnable poison in nuclear fuel: towards a boron free PWR

    International Nuclear Information System (INIS)

    Pieck, D.

    2013-01-01

    Reactivity excess in Nuclear Power Plants is controlled by reactor's active systems: boric acid dilution and control rods. Alternatively, negative reactivity insertion can be made in a passive way using burnable poisons, i.e. neutron absorbers, this is the case of gadolinium (Gd). In the industrial framework of U 235 enrichment increase and boric acid restraint, the goal of this thesis is to optimize the distribution of gadolinium in UO 2 ceramics to obtain a high-performance provision of negative reactivity in Pressurized Water Reactors. In this sense, the work is focus on new gadolinium-rich materials. Thus, U-Gd-O phase diagram was explored in the field of high Gd contents. Two cubic phases were found and characterized: the C1 and C2 phases. With the aim of an industrial application, C1 phase was selected as candidate for Gd addition into UO 2 pellets. The optimal distribution of C1 phase within a nuclear fuel assembly was studied using APOLLO 2.8 neutron transport code. Parametric calculations were performed. These neutronic studies have ends in a successful 'concept of poisoned pellet'. Finally, some prototype pellets following this concept were made in laboratory to proof it feasibility. All the obtained results shows that the proposed concept of a neutro-phage C1-phase coating on UO 2 pellets is a convenient way to reduce reactivity excess within the framework of long irradiation cycles. This concept could be potentially applied in industrial scale. Consequently a patent application process was initiated.(author) [fr

  11. An overview of techniques for the measurement of calcium distribution, calcium fluxes, and cytosolic free calcium in mammalian cells

    International Nuclear Information System (INIS)

    Borle, A.B.

    1990-01-01

    An array of techniques can be used to study cell calcium metabolism that comprises several calcium compartments and many types of transport systems such as ion channels, ATP-dependent pumps, and antiporters. The measurement of total call calcium brings little information of value since 60 to 80% of total cell calcium is actually bound to the extracellular glycocalyx. Cell fractionation and differential centrifugation have been used to study intracellular Ca 2+ compartmentalization, but the methods suffer from the possibility of Ca 2+ loss or redistribution among cell fractions. Steady-state kinetic analyses of 45 Ca uptake or desaturation curves have been used to study the distribution of Ca 2+ among various kinetic pools in living cells and their rate of Ca 2+ exchange, but the analyses are constrained by many limitations. Nonsteady-state tracer studies can provide information about rapid changes in calcium influx or efflux in and out of the cell. Zero-time kinetics of 45 Ca uptake can detect instantaneous changes in calcium influx, while 45 Ca fractional efflux ratio, can detect rapid stimulations or inhibitions of calcium efflux out of cells. The best strategy to study cell calcium metabolism is to use several different methods that focus on a specific problem from widely different angles

  12. Use of gadolinium chloride as a contrast agent for imaging spruce knots by magnetic resonance

    Science.gov (United States)

    Thomas L. Eberhardt; Chi-Leung So; Amy H. Herlihy; Po-Wah So

    2006-01-01

    Treatments of knot-containing spruce wood blocks with a paramagnetic salt, gadolinium (III) chloride, in combination with solvent pretreatments, were evaluated as strategies to enhance the visualization of wood features by magnetic resonance imaging (MRI). Initial experiments with clear wood and excised knot samples showed differences in moisture uptake after...

  13. Comparison between gadolinium-enhanced 2D T1-weighted gradient-echo and spin-echo sequences in the detection of active multiple sclerosis lesions on 3.0T MRI

    Energy Technology Data Exchange (ETDEWEB)

    Aymerich, F.X. [Hospital Universitari Vall d' Hebron, Universitat Autonoma de Barcelona, MR Unit. Department of Radiology (IDI), Barcelona (Spain); Universitat Politecnica de Catalunya - Barcelona Tech (UPC), Department of Automatic Control (ESAII), Barcelona (Spain); Auger, C.; Alcaide-Leon, P.; Pareto, D.; Huerga, E.; Corral, J.F.; Mitjana, R.; Rovira, A. [Hospital Universitari Vall d' Hebron, Universitat Autonoma de Barcelona, MR Unit. Department of Radiology (IDI), Barcelona (Spain); Sastre-Garriga, J.; Montalban, X. [Hospital Universitari Vall d' Hebron, Universitat Autonoma de Barcelona, Centre d' Esclerosi Multiple de Catalunya (Cemcat), Department of Neurology/Neuroimmunology, Barcelona (Spain)

    2017-04-15

    To compare the sensitivity of enhancing multiple sclerosis (MS) lesions in gadolinium-enhanced 2D T1-weighted gradient-echo (GRE) and spin-echo (SE) sequences, and to assess the influence of visual conspicuity and laterality on detection of these lesions. One hundred MS patients underwent 3.0T brain MRI including gadolinium-enhanced 2D T1-weighted GRE and SE sequences. The two sets of contrast-enhanced scans were evaluated in random fashion by three experienced readers. Lesion conspicuity was assessed by the image contrast ratio (CR) and contrast-to-noise ratio (CNR). The intracranial region was divided into four quadrants and the impact of lesion location on detection was assessed in each slice. Six hundred and seven gadolinium-enhancing MS lesions were identified. GRE images were more sensitive for lesion detection (0.828) than SE images (0.767). Lesions showed a higher CR in SE than in GRE images, whereas the CNR was higher in GRE than SE. Most misclassifications occurred in the right posterior quadrant. The gadolinium-enhanced 2D T1-weighted GRE sequence at 3.0T MRI enables detection of enhancing MS lesions with higher sensitivity and better lesion conspicuity than 2D T1-weighted SE. Hence, we propose the use of gadolinium-enhanced GRE sequences rather than SE sequences for routine scanning of MS patients at 3.0T. (orig.)

  14. Gadolinium(III) ion selective sensor using a new synthesized Schiff's base as a sensing material

    Energy Technology Data Exchange (ETDEWEB)

    Zamani, Hassan Ali, E-mail: haszamani@yahoo.com [Department of Applied Chemistry, Mashhad Branch, Islamic Azad University, Mashhad (Iran, Islamic Republic of); Mohammadhosseini, Majid [Department of Chemistry, Faculty of Basic Sciences, Shahrood Branch, Islamic Azad University, Shahrood (Iran, Islamic Republic of); Haji-Mohammadrezazadeh, Saeed [Department of Chemistry, Payame Noor University, Ardakan (Iran, Islamic Republic of); Faridbod, Farnoush [Endocrinology and Metabolism Research Center, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Ganjali, Mohammad Reza [Endocrinology and Metabolism Research Center, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Center of Excellence in Electrochemistry, Faculty of Chemistry, University of Tehran, Tehran (Iran, Islamic Republic of); Meghdadi, Soraia [Department of Chemistry, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of); Davoodnia, Abolghasem [Department of Chemistry, Faculty of Sciences, Mashhad Branch, Islamic Azad University, Mashhad (Iran, Islamic Republic of)

    2012-05-01

    According to a solution study which showed a selective complexation between N,N Prime -bis(methylsalicylidene)-2-aminobenzylamine (MSAB) and gadolinium ions, MSAB was used as a sensing element in construction of a gadolinium(III) ion selective electrode. Acetophenon (AP) was used as solvent mediator and sodium tetraphenyl borate (NaTPB) as an anion excluder. The electrode showed a good selectivity towards Gd(III) ions over a wide variety of cations tested. The constructed sensor displayed a Nernstian behavior (19.7 {+-} 0.3 mV/decade) in the concentration range of 1.0 Multiplication-Sign 10{sup -6} to 1.0 Multiplication-Sign 10{sup -2} mol L{sup -1} with detection limit of 5.0 Multiplication-Sign 10{sup -7} mol L{sup -1} and a short response time (< 10 s). The working pH range of the electrode was 3.5-10.1 and lifetime of the sensor was at least 10 weeks. Analysis of certified reference materials confirmed the accuracy of the proposed sensor. The electrode was successfully applied as an indicator electrode in gadolinium titration with EDTA. - Highlights: Black-Right-Pointing-Pointer A Gd{sup 3+}-PVC membrane sensor based on an ion carrier as sensing material is introduced. Black-Right-Pointing-Pointer This technique is very simple and it's not necessary to use sophisticated equipment. Black-Right-Pointing-Pointer This sensor shows good selectivity against other metal ions.

  15. Calcium and Mitosis

    Science.gov (United States)

    Hepler, P.

    1983-01-01

    Although the mechanism of calcium regulation is not understood, there is evidence that calcium plays a role in mitosis. Experiments conducted show that: (1) the spindle apparatus contains a highly developed membrane system that has many characteristics of sarcoplasmic reticulum of muscle; (2) this membrane system contains calcium; and (3) there are ionic fluxes occurring during mitosis which can be seen by a variety of fluorescence probes. Whether the process of mitosis can be modulated by experimentally modulating calcium is discussed.

  16. Differential diagnosis between adrenal adenomas and non-adenomas with gadolinium MR in delayed scans: another diagnostic possibility

    International Nuclear Information System (INIS)

    Mondello, Eduardo J.; Eyheremendy, Eduardo P.; Stoisa, Daniela

    2001-01-01

    Purpose: To determine the value of measuring delayed post gadolinium signal intensity by displaying a curve, to make the differential diagnosis between adrenal adenomas and non-adenomas, and compare it to chemical shift MR imaging and unenhanced/delayed contrast enhanced CT. Material and methods: Nine adrenal masses have been evaluated by unenhanced/delayed contrast enhanced CT, chemical shift MR imaging and Dynamic Scan at 5, 15, 30 minutes or more, with measurement curves. The 'in phase' imaging have been compared to the 'out phase' ones. Results: Adenomas have shown drop of the curve at 30 minutes of the contrast injection. Non-adenomas have conserved an ascending curve with the same delay. Conclusion: Gadolinium-enhanced MR imaging at delayed scans can characterize adrenal masses as adenomas or non-adenomas. This technique could be considered as a new complementary diagnostic method. (author)

  17. Critical phenomena and exchange interactions of an amorphous ferromagnet: gadolinium--gold

    International Nuclear Information System (INIS)

    Poon, S.J.; Durand, J.

    1976-07-01

    Magnetization was measured between 4 and 290 0 K in fields up to 70 kOe on liquid-quenched Gd 80 Au 20 amorphous alloys. The Curie temperature and critical exponents β, γ and delta are found to be 149.45 0 K, 0.439, 1.294 and 3.948 respectively. These values are compared with the Heisenberg and molecular field values. The data are fitted to an equation of state previously derived for second order phase transition in fluid systems. The results illustrate clearly a second order phase transition in the amorphous state. A discussion in terms of the Heisenberg model is presented. The effective magnetic moment in the paramagnetic state has a value of 9.37 μ/sub B/ per gadolinium atom. The saturation moment extrapolated to 0 0 K is 7.0 μ/sub B/ per gadolinium atom. The low temperature saturation magnetization observes the T/sup 3 / 2 / law from 0.13 T/sub c/ to 0.80 T/sub c/. The effective exchange integrals J/sub n/ determined from the Rushbrooke--Wood formula and spin-wave theory are found to be 2.28 and 1.34 0 K respectively. The differences in J/sub n/ and that between the effective moment and saturation moment are attributed to the nearest-neighbor antiferromagnetic couplings below T/sub c/. Possible effects of structural disorder on the magnetic properties of Gd in the amorphous state are discussed

  18. SWI enhances vein detection using gadolinium in multiple sclerosis

    International Nuclear Information System (INIS)

    Maggi, Pietro; Mazzoni, Lorenzo N; Moretti, Marco; Grammatico, Matteo; Chiti, Stefano; Massacesi, Luca

    2015-01-01

    Susceptibility weighted imaging (SWI) combined with the FLAIR sequence provides the ability to depict in vivo the perivenous location of inflammatory demyelinating lesions – one of the most specific pathologic features of multiple sclerosis (MS). In addition, in MS white matter (WM) lesions, gadolinium-based contrast media (CM) can increase vein signal loss on SWI. This report focuses on two cases of WM inflammatory lesions enhancing on SWI images after CM injection. In these lesions in fact the CM increased the contrast between the parenchyma and the central vein allowing as well, in one of the two cases, the detection of a vein not visible on the same SWI sequence acquired before CM injection

  19. Calcium ion binding properties of Medicago truncatula calcium/calmodulin-dependent protein kinase.

    Science.gov (United States)

    Swainsbury, David J K; Zhou, Liang; Oldroyd, Giles E D; Bornemann, Stephen

    2012-09-04

    A calcium/calmodulin-dependent protein kinase (CCaMK) is essential in the interpretation of calcium oscillations in plant root cells for the establishment of symbiotic relationships with rhizobia and mycorrhizal fungi. Some of its properties have been studied in detail, but its calcium ion binding properties and subsequent conformational change have not. A biophysical approach was taken with constructs comprising either the visinin-like domain of Medicago truncatula CCaMK, which contains EF-hand motifs, or this domain together with the autoinhibitory domain. The visinin-like domain binds three calcium ions, leading to a conformational change involving the exposure of hydrophobic surfaces and a change in tertiary but not net secondary or quaternary structure. The affinity for calcium ions of visinin-like domain EF-hands 1 and 2 (K(d) = 200 ± 50 nM) was appropriate for the interpretation of calcium oscillations (~125-850 nM), while that of EF-hand 3 (K(d) ≤ 20 nM) implied occupancy at basal calcium ion levels. Calcium dissociation rate constants were determined for the visinin-like domain of CCaMK, M. truncatula calmodulin 1, and the complex between these two proteins (the slowest of which was 0.123 ± 0.002 s(-1)), suggesting the corresponding calcium association rate constants were at or near the diffusion-limited rate. In addition, the dissociation of calmodulin from the protein complex was shown to be on the same time scale as the dissociation of calcium ions. These observations suggest that the formation and dissociation of the complex between calmodulin and CCaMK would substantially mirror calcium oscillations, which typically have a 90 s periodicity.

  20. Calcium Carbonate

    Science.gov (United States)

    ... Calcium is needed by the body for healthy bones, muscles, nervous system, and heart. Calcium carbonate also ... to your pharmacist or contact your local garbage/recycling department to learn about take-back programs in ...

  1. Calcium en cardioplegie

    NARCIS (Netherlands)

    Ruigrok, T.J.C.; Meijler, F.L.

    1985-01-01

    Coronary perfusion with a calcium-free solution, followed by reperfusion with a calcium containing solution, may result in acute myocardial cell death and in irreversible loss of the e1ectrical and mechanical activity of the heart. This phenomenon is known as the calcium paradox. A number of

  2. Calcium Electroporation

    DEFF Research Database (Denmark)

    Frandsen, Stine Krog; Gibot, Laure; Madi, Moinecha

    2015-01-01

    BACKGROUND: Calcium electroporation describes the use of high voltage electric pulses to introduce supraphysiological calcium concentrations into cells. This promising method is currently in clinical trial as an anti-cancer treatment. One very important issue is the relation between tumor cell kill...... efficacy-and normal cell sensitivity. METHODS: Using a 3D spheroid cell culture model we have tested the effect of calcium electroporation and electrochemotherapy using bleomycin on three different human cancer cell lines: a colorectal adenocarcinoma (HT29), a bladder transitional cell carcinoma (SW780......), and a breast adenocarcinoma (MDA-MB231), as well as on primary normal human dermal fibroblasts (HDF-n). RESULTS: The results showed a clear reduction in spheroid size in all three cancer cell spheroids three days after treatment with respectively calcium electroporation (p

  3. One color multi-photon ionization of the Gadolinium atom in near UV region

    International Nuclear Information System (INIS)

    Kim, Jin Tae; Yi, Jong Hoon; Lhee, Yong Joo; Lee, Jong Min

    1999-01-01

    We have investigated the states of the gadolinium atom in near ultra-violet (UV) region (∼410 nm) using single photon excitation using resonance ionization mass spectrometry (RIMS). Around 70 transitions among observed 180 single color multi-photon ionization signals have been assigned. Most of the multi-photon processes of the assigned ion signals are through single photon resonant three photon ionization and through two photon resonant three photon ionization. (author)

  4. Low Temperature Synthesis and Properties of Gadolinium-Doped Cerium Oxide Nanoparticles

    DEFF Research Database (Denmark)

    Machado, Marina F. S.; P. R. Moraes, Leticia; Monteiro, Natalia K.

    2017-01-01

    Gadolinium-doped cerium oxide (GDC) is an attractive ceramic material for solid oxide fuel cells (SOFCs) both as the electrolyte or in composite electrodes. The Ni/GDC cermet can be tuned as a catalytic layer, added to the conventional Ni/yttria-stabilized zirconia (YSZ), for the internal steam...... sintering temperature needed to obtain a fully dense ceramic body, which can result in undesired reactions with YSZ. In this study, a green chemistry route for the synthesis of 10 mol% GDC nanoparticles is proposed. Such a low temperature synthesis provides control over particle size and sinterability...

  5. Low Temperature Synthesis and Properties of Gadolinium-Doped Cerium Oxide Nanoparticles

    DEFF Research Database (Denmark)

    Machado, M. F. S.; Moraes, L. P. R.; Monteiro, N. K.

    2017-01-01

    Gadolinium-doped cerium oxide (GDC) is an attractive ceramic material for solid oxide fuel cells (SOFCs) both as the electrolyte and in composite electrodes operating at low and intermediate temperatures. GDC exhibits high oxygen ion conductivity at a wide range of temperatures and displays a high...... resistance to carbon deposition when hydrocarbons are used as fuels. However, an inconvenience of ceria-based oxides is the high sintering temperature needed to obtain a fully dense ceramic body. In this study, a green chemistry route for the synthesis of 10 mol% GDC nanoparticles is proposed. The aqueous...

  6. Effect of calcium intake on urinary oxalate excretion in calcium stone-forming patients

    Directory of Open Access Journals (Sweden)

    Nishiura J.L.

    2002-01-01

    Full Text Available Dietary calcium lowers the risk of nephrolithiasis due to a decreased absorption of dietary oxalate that is bound by intestinal calcium. The aim of the present study was to evaluate oxaluria in normocalciuric and hypercalciuric lithiasic patients under different calcium intake. Fifty patients (26 females and 24 males, 41 ± 10 years old, whose 4-day dietary records revealed a regular low calcium intake (<=500 mg/day, received an oral calcium load (1 g/day for 7 days. A 24-h urine was obtained before and after load and according to the calciuria under both diets, patients were considered as normocalciuric (NC, N = 15, diet-dependent hypercalciuric (DDHC, N = 9 or diet-independent hypercalciuric (DIHC, N = 26. On regular diet, mean oxaluria was 30 ± 14 mg/24 h for all patients. The 7-day calcium load induced a significant decrease in mean oxaluria compared to the regular diet in NC and DIHC (20 ± 12 vs 26 ± 7 and 27 ± 18 vs 32 ± 15 mg/24 h, respectively, P<0.05 but not in DDHC patients (22 ± 10 vs 23 ± 5 mg/24 h. The lack of an oxalate decrease among DDHC patients after the calcium load might have been due to higher calcium absorption under higher calcium supply, with a consequent lower amount of calcium left in the intestine to bind with oxalate. These data suggest that a long-lasting regular calcium consumption <500 mg was not associated with high oxaluria and that a subpopulation of hypercalciuric patients who presented a higher intestinal calcium absorption (DDHC tended to hyperabsorb oxalate as well, so that oxaluria did not change under different calcium intake.

  7. Calcium - ionized

    Science.gov (United States)

    ... diuretics Thrombocytosis (high platelet count) Tumors Vitamin A excess Vitamin D excess Lower-than-normal levels may be due to: Hypoparathyroidism Malabsorption Osteomalacia Pancreatitis Renal failure Rickets Vitamin D deficiency Alternative Names Free calcium; Ionized calcium ...

  8. Calcium absorption and achlorhydria

    International Nuclear Information System (INIS)

    Recker, R.R.

    1985-01-01

    Defective absorption of calcium has been thought to exist in patients with achlorhydria. The author compared absorption of calcium in its carbonate form with that in a pH-adjusted citrate form in a group of 11 fasting patients with achlorhydria and in 9 fasting normal subjects. Fractional calcium absorption was measured by a modified double-isotope procedure with 0.25 g of calcium used as the carrier. Mean calcium absorption (+/- S.D.) in the patients with achlorhydria was 0.452 +/- 0.125 for citrate and 0.042 +/- 0.021 for carbonate (P less than 0.0001). Fractional calcium absorption in the normal subjects was 0.243 +/- 0.049 for citrate and 0.225 +/- 0.108 for carbonate (not significant). Absorption of calcium from carbonate in patients with achlorhydria was significantly lower than in the normal subjects and was lower than absorption from citrate in either group; absorption from citrate in those with achlorhydria was significantly higher than in the normal subjects, as well as higher than absorption from carbonate in either group. Administration of calcium carbonate as part of a normal breakfast resulted in completely normal absorption in the achlorhydric subjects. These results indicate that calcium absorption from carbonate is impaired in achlorhydria under fasting conditions. Since achlorhydria is common in older persons, calcium carbonate may not be the ideal dietary supplement

  9. Mediastinal lymphoma: quantitative changes in gadolinium enhancement at MR imaging after treatment.

    Science.gov (United States)

    Rahmouni, A; Divine, M; Lepage, E; Jazaerli, N; Belhadj, K; Gaulard, P; Golli, M; Reyes, F; Vasile, N

    2001-06-01

    To compare changes in gadolinium enhancement at magnetic resonance (MR) imaging with outcome in mediastinal lymphoma after treatment. Thirty-one patients with bulky mediastinal lymphoma (17 with Hodgkin disease, 14 with non-Hodgkin lymphoma) underwent serial MR imaging before and up to 50 months after treatment, with routine follow-up (including computed tomography). Signal intensity ratios between masses and muscle were calculated on T1-weighted, T2-weighted, and contrast material-enhanced T1-weighted spin-echo MR images. The percentage enhancement and signal intensity ratios of mediastinal masses on T2-weighted MR images were calculated at diagnosis and during and after treatment. Twenty-one patients with persistent complete remission had a mean percentage enhancement of residual masses (4%; range, -26% to 40%) that was significantly lower than that of initial masses (78%; range, 41%-124%). Although the mean signal intensity ratio of residual masses on T2-weighted images was significantly lower than that of initial masses, an increase in this ratio was observed in four patients after treatment. In seven patients with relapse, the percentage enhancement value of the residual mass was as high as that of the initial mass. Gadolinium enhancement of lymphomatous masses of the mediastinum decreased markedly after treatment in patients in continuous complete remission but not in patients with relapse.

  10. Study of calcium chloride and calcium nitrate purification on inorganic sorbents

    International Nuclear Information System (INIS)

    Vasil'eva, L.V.; Knyazeva, A.N.; Fakeev, A.A.; Belyaeva, N.A.; Morozov, V.I.; Kucherova, V.V.

    1986-01-01

    Purification of calcium chloride and calcium nitrate from iron, chromium, manganese and cobalt impurities by sorption on some inorganic collectors are considered in this article. Study was conducted by means of radioactive-tracer technique at concurrent use of several γ-radioactive isotopes. As a collectors were used hydrated aluminium and zirconium oxides. Dependence of effectiveness of precipitation by collectors on ph-value of medium, quantity of collector, nature and concentration of components is studied. Optimal parameters of purification of calcium chloride and calcium nitrate are defined.

  11. MRI evaluation of myometrial invasion by endometrial carcinoma. Comparison between fast-spin-echo T2W and coronal FMPSPGR Gadolinium-Dota-Enhanced Sequences

    International Nuclear Information System (INIS)

    Nasi, Francesca; Fiocchi, Federica; Pecchi, Annarita; Torricelli, Pietro; Rivasi, Francesco

    2005-01-01

    Purpose. The depth of myometrial invasion by endometrial carcinoma strongly affects the incidence of metastasis to regional nodes and influences the surgical strategies. The aim of this paper is to compare the results of FSE T2-w and Gadolinium-enhanced FMPSGR MR sequences in assessing the depth of myometrial invasion by endometrial cancer. Materials and methods. Forty-five women with histopathologically-proven endometrial carcinoma underwent preoperative MRI. Axial SE TI w, axial, sagittal and para-coronal FSE T2w and para-coronal Gadolinium enhanced FMPSGR sequences were performed using a high field strength magnet (1.5T). Within one month of MR all patients underwent hysterectomy, and anatomical evaluation of the surgical specimen was done sectioning the uterus along the short axis. Based upon the results of the histological evaluation the results of the FSE T2w and Gadolinium-enhanced sequences were compared and the statistical difference between the results obtained was statistically evaluated. Results. The histological evaluation showed intra mucosal neoplasm in 11 patients, myometrial infiltration less than 50% in 31 patients, myometrial infiltration more than 50% in 12 patients and transmural cancer 1 patient. Statistical evaluation showed that the FSE T2w sequence had a global sensitivity and specificity of 80.6% and 87.6%, respectively, with a mean Negative Predictive Value of 92.6% and a mean Positive Predictive Value of 86%. Gadolinium-enhanced FMPSPGR sequence had a global sensitivity and specificity of 90.6% and 93.3%, respectively, with a mean Negative Predictive Value of 96,3% and a mean Positive Predictive Value of 88%. The staging accuracy (χ 2 test) on FMPSPGR images (95%) was higher than that on FSE T2w images (78%). Conclusions. In our experience Gadolinium-enhanced dynamic sequences increase the accuracy of MR imaging in diagnosing the depth of myometrial invasion. In particular they improve the visualisation of the inner myometrium, the so

  12. Gadolinium as a CT contrast agent: an experimental study for the effects of injection parameters in the rabbit brain model

    International Nuclear Information System (INIS)

    Kim, Hyun Jin; Choi, Hye Young; Lee, Sun Wha; Hwang, Ji Young

    2005-01-01

    We wanted to investigate the use of gadolinium based contrast agent (Gd-DTPA) for computed tomography (CT), and we also wanted to assess the effects of valuable injection parameters on enhancement in an experimental rabbit brain model. In vitro, attenuation measurements of serial dilutions of Gd-DTPA and iopromide were compared. In five rabbits, single level dynamic gadolinium-enhanced brain CT studies were obtained using different injection parameters. A comparision CT scan after iopromide administration was performed. The time-attenuation curves of the brain vessel and parenchyma were obtained and the magnitude of enhancement (Hmax) and the time to peak enhancement (Tmax) were analyzed. In vitro, the attenuation coefficient of undiluted Gd-DTPA (2,578 HU) was higher than that of iopromide (1,761 HU) at equimolar concentrations. In 5 rabbits, the time-attenuation curve demonstrated a distinct pattern with peak enhancement only in the brain vessel, but not in the brain parenchyma. There was increasing linear relationship between the injection rate of Gd-DTPA and Hmax, and a declining linear relationship with Tmax. The higher the concentration of Gd-DTPA, the higher Hmax was, but no significant difference was found for the Tmax. Higher volumes of Gd-DTPA revealed a higher Hmax and a delayed Tmax. Enhancement of the brain parenchyma on gadolinium-enhanced CT is minimal, while enhancement of the brain vessels is distinctive. The most important factor affecting Hmax of the vessel is the concentration of the contrast medium and the most important factor affecting Tmax of the vessel is volume of the contrast medium. The gadolinium-based contrast agent may be an reasonable alternative contrast agent for brain CT, and especially in cerebral vessels, and it may also be advantageous for brain parenchyma of those patients with BBB dysfunction

  13. Gadolinium(III) ion selective sensor using a new synthesized Schiff's base as a sensing material

    International Nuclear Information System (INIS)

    Zamani, Hassan Ali; Mohammadhosseini, Majid; Haji-Mohammadrezazadeh, Saeed; Faridbod, Farnoush; Ganjali, Mohammad Reza; Meghdadi, Soraia; Davoodnia, Abolghasem

    2012-01-01

    According to a solution study which showed a selective complexation between N,N′-bis(methylsalicylidene)-2-aminobenzylamine (MSAB) and gadolinium ions, MSAB was used as a sensing element in construction of a gadolinium(III) ion selective electrode. Acetophenon (AP) was used as solvent mediator and sodium tetraphenyl borate (NaTPB) as an anion excluder. The electrode showed a good selectivity towards Gd(III) ions over a wide variety of cations tested. The constructed sensor displayed a Nernstian behavior (19.7 ± 0.3 mV/decade) in the concentration range of 1.0 × 10 −6 to 1.0 × 10 −2 mol L −1 with detection limit of 5.0 × 10 −7 mol L −1 and a short response time ( 3+ –PVC membrane sensor based on an ion carrier as sensing material is introduced. ► This technique is very simple and it's not necessary to use sophisticated equipment. ► This sensor shows good selectivity against other metal ions.

  14. Signal effects of various radiographic contrast media and their interaction with gadolinium DTPA during MRT

    International Nuclear Information System (INIS)

    Kopka, L.; Funke, M.; Fischer, U.; Vosshenrich, R.; Schroeder, M.; Grabbe, E.

    1994-01-01

    T 1 and T 2 weighted signals dereived from various radiological contrast media were studied during MRT spin-echo sequences. In addition, the interaction between radiological contrast media and Gadolinium-DTPA concerning T 1 signals was evaluated. Ionic (ioxitalaminic acid) and non-ionic radiological contrast media (Iopromid, Iotrolan) were used in diagnostic concentrations. Measurements were carried out with a superconductive magnet of 1.5 Tesla. Radiological contrast media produced significantly higher signals than a physiological sodium chloride solution in T 1 -weighted spin-echo sequences. Evn small amounts (15% of total volume) of radiological contrast media during T 1 -weighted spin-echo sequences led to a significant reduction (about 25%) of the signal intensity of a 2 mM Gadolinium-DTPA solution. This may lead to diagnostic problems, as was shown in a series of 25 MR arthrograms of the shoulder. It is recommended than an interval of at least 6 hours should elapse between the use of a radiological contrst medium and an MRT examination. (orig.) [de

  15. Thermal neutron capture cross section of gadolinium by pile-oscillation measurements in MINERVE

    International Nuclear Information System (INIS)

    Leconte, P.; Di-Salvo, J.; Antony, M.; Pepino, A.; Hentati, A.

    2012-01-01

    Natural gadolinium is used as a burnable poison in most LWR to account for the excess of reactivity of fresh fuels. For an accurate prediction of the cycle length, its nuclear data and especially its neutron capture cross section needs to be known with a high precision. Recent microscopic measurements at Rensselaer Polytechnic Inst. (RPI) suggest a 11% smaller value for the thermal capture cross section of 157 Gd, compared with most of evaluated nuclear data libraries. To solve this inconsistency, we have analyzed several pile-oscillation experiments, performed in the MINERVE reactor. They consist in the measurement of the reactivity variation involved by the introduction in the reactor of small-samples, containing different mass amounts of natural gadolinium. The analysis of these experiments is done through the exact perturbation theory, using the PIMS calculation tool, in order to link the reactivity effect to the thermal capture cross section. The measurement of reactivity effects is used to deduce the 2200 m.s-1 capture cross section of nat Gd which is (49360 ± 790) b. This result is in good agreement with the JEFF3.1.1 value (48630 b), within 1.6% uncertainty at 1σ, but is strongly inconsistent with the microscopic measurements at RPI which give (44200 ± 500) b. (authors)

  16. Investigation of Plutonium and Uranium Precipitation Behavior with Gadolinium as a Neutron Poison

    CERN Document Server

    Visser, A E

    2003-01-01

    The caustic precipitation of plutonium (Pu)-containing solutions has been investigated to determine whether the presence of 3:1 uranium (U):Pu in solutions stored in the H-Canyon Facility at the U.S. Department of Energy's (DOE) Savannah River Site (SRS) would adversely impact the use of gadolinium nitrate (Gd(NO3)3) as a neutron poison. In the past, this disposition strategy has been successfully used to discard solutions containing approximately 100 kg of Pu to the SRS high level waste (HLW) system. In the current experiments, gadolinium (as Gd(NO3)3) was added to samples of a 3:1 U:Pu solution, a surrogate 3 g/L U solution, and a surrogate 3 g/L U with 1 g/L Pu solution. A series of experiments was then performed to observe and characterize the precipitate at selected pH values. Solids formed at pH 4.5 and were found to contain at least 50 percent of the U and 94 percent of the Pu, but only 6 percent of the Gd. As the pH of the solution increased (e.g., pH greater than 14 with 1.2 or 3.6 M sodium hydroxide...

  17. Gamma ray induced thermoluminescence studies of yttrium (III oxide nanopowders doped with gadolinium

    Directory of Open Access Journals (Sweden)

    Raunak Kumar Tamrakar

    2014-10-01

    Full Text Available Y2O3:Gd3+ nanophosphor was prepared by the solid state reaction method. Systematic studies have been done to investigate the structural and optical properties of the gadolinium doped Y2O3 phosphor. The prepared phosphor was characterized by using X-ray diffractometer (XRD, scanning electron microscopy (SEM, transmission electron microscopy and UV–VIS–NIR spectrophotometer. The XRD patterns reveal that these prepared phosphors have cubic phase crystal structure. SEM and TEM images showed uniform doping of the material over the entire materials. The energy band gap for gadolinium doped Y2O3 phosphor was revealed from the optical studies and was found to 5.1 eV. The prepared phosphors were also examined by thermoluminescence technique. The kinetic parameters like trap depth, frequency factor were calculated by using the Peak shape method, which are discussed in details. The TL Glow curves were fitted in CGCD (computerized glow curve convolution deconvolution technique & trapping parameters calculated. The TL parameters such as activation energy for deconvoluted peak were found in the range of 0.82–2.24 eV. The frequency factor is of the order of between of 1.78 × 1012 and 9.84 × 1020 s−1.

  18. Thermal neutron capture cross section of gadolinium by pile-oscillation measurements in MINERVE

    Energy Technology Data Exchange (ETDEWEB)

    Leconte, P.; Di-Salvo, J.; Antony, M.; Pepino, A. [CEA, DEN, DER, Cadarache, F-13108 Saint-Paul-Lez-Durance (France); Hentati, A. [International School in Nuclear Engineering, Cadarache, F-13108 Saint-Paul-Lez-Durance (France)

    2012-07-01

    Natural gadolinium is used as a burnable poison in most LWR to account for the excess of reactivity of fresh fuels. For an accurate prediction of the cycle length, its nuclear data and especially its neutron capture cross section needs to be known with a high precision. Recent microscopic measurements at Rensselaer Polytechnic Inst. (RPI) suggest a 11% smaller value for the thermal capture cross section of {sup 157}Gd, compared with most of evaluated nuclear data libraries. To solve this inconsistency, we have analyzed several pile-oscillation experiments, performed in the MINERVE reactor. They consist in the measurement of the reactivity variation involved by the introduction in the reactor of small-samples, containing different mass amounts of natural gadolinium. The analysis of these experiments is done through the exact perturbation theory, using the PIMS calculation tool, in order to link the reactivity effect to the thermal capture cross section. The measurement of reactivity effects is used to deduce the 2200 m.s-1 capture cross section of {sup nat}Gd which is (49360 {+-} 790) b. This result is in good agreement with the JEFF3.1.1 value (48630 b), within 1.6% uncertainty at 1{sigma}, but is strongly inconsistent with the microscopic measurements at RPI which give (44200 {+-} 500) b. (authors)

  19. Neuroradiologic findings in leptomeningeal carcinomatosis: The value interest of gadolinium-enhanced MRI

    International Nuclear Information System (INIS)

    Rodesch, G.; Baleriaux, D.; Bogaert, P. van; Mavroudakis, N.; Hildebrand, J.; Parizel, P.M.; Martin, J.J.; Segebarth, C.; Vyve, M. van

    1990-01-01

    Four patients with leptomeningeal metastases documented by neuroradiological examinations are reported. All had central nervous system or systemic neoplasms and showed clinical signs of carcinomatous meningitis. Gadolinium-enhanced MRI (Gd-MRI) disclosed for each patient pathological foci, allowing delineation of the extent of meningeal disease. Although non-specific, these findings, combined with the clinical context and CSF analysis, may lead to a rapid diagnosis and treatment of carcinomatous meningitis, even when malignant cells are not detected in the cerebrospinal fluid. (orig.)

  20. Dielectric properties of gadolinium molybdate in low- and infralow frequency electric fields

    International Nuclear Information System (INIS)

    Galiyarova, N.M.; Gorin, S.V.; Dontsova, L.I.; Shil'nikov, A.V.; Shuvalov, L.A.; AN SSSR, Moscow

    1992-01-01

    Temperature dependences of complex dielectric permittivity of gadolinium molybdate (GMO) in low- (LF) and infralow-frequency (ILF) electric fields with 0.1 V·cm -1 amplitude within 0.25-10 4 Hz frequency range are studied. Substantial effect of the crystal prehistory on LF and ILF dielectric properties and domain structure state is revealed. An anomalous reduction of complex dielectric permittivity accompanied by the occurrence of the Debye LF-dispersion of permittivity is detected under the sample cooling from a nonpolar phase

  1. Atomic layer deposition of calcium oxide and calcium hafnium oxide films using calcium cyclopentadienyl precursor

    International Nuclear Information System (INIS)

    Kukli, Kaupo; Ritala, Mikko; Sajavaara, Timo; Haenninen, Timo; Leskelae, Markku

    2006-01-01

    Calcium oxide and calcium hafnium oxide thin films were grown by atomic layer deposition on borosilicate glass and silicon substrates in the temperature range of 205-300 o C. The calcium oxide films were grown from novel calcium cyclopentadienyl precursor and water. Calcium oxide films possessed refractive index 1.75-1.80. Calcium oxide films grown without Al 2 O 3 capping layer occurred hygroscopic and converted to Ca(OH) 2 after exposure to air. As-deposited CaO films were (200)-oriented. CaO covered with Al 2 O 3 capping layers contained relatively low amounts of hydrogen and re-oriented into (111) direction upon annealing at 900 o C. In order to examine the application of CaO in high-permittivity dielectric layers, mixtures of Ca and Hf oxides were grown by alternate CaO and HfO 2 growth cycles at 230 and 300 o C. HfCl 4 was used as a hafnium precursor. When grown at 230 o C, the films were amorphous with equal amounts of Ca and Hf constituents (15 at.%). These films crystallized upon annealing at 750 o C, showing X-ray diffraction peaks characteristic of hafnium-rich phases such as Ca 2 Hf 7 O 16 or Ca 6 Hf 19 O 44 . At 300 o C, the relative Ca content remained below 8 at.%. The crystallized phase well matched with rhombohedral Ca 2 Hf 7 O 16 . The dielectric films grown on Si(100) substrates possessed effective permittivity values in the range of 12.8-14.2

  2. Calcium sensing in exocytosis

    DEFF Research Database (Denmark)

    Gustavsson, Natalia; Wu, Bingbing; Han, Weiping

    2012-01-01

    an increase in intracellular calcium levels. Besides the triggering role, calcium signaling modulates the precise amount and kinetics of vesicle release. Thus, it is a central question to understand the molecular machineries responsible for calcium sensing in exocytosis. Here we provide an overview of our...... current understanding of calcium sensing in neurotransmitter release and hormone secretion....

  3. 77 FR 42317 - Establish a Patient-Based Registry To Evaluate the Association of Gadolinium Based Contrast...

    Science.gov (United States)

    2012-07-18

    ... Quality Assurance (QA) registry of patients with renal failure who received GBCAs as the basis for a... of the development of a patient-based registry to evaluate the association of gadolinium based..., and a copy to Ira Krefting, Center for Drug Evaluation and Research, Division of Medical Imaging...

  4. Investigation of suspected Guillain-Barre syndrome in childhood: what is the role for gadolinium enhanced magnetic resonance imaging of the spine?

    Science.gov (United States)

    Smith, Nicholas; Pereira, John; Grattan-Smith, Padraic

    2014-10-01

    To review the role of gadolinium-enhanced magnetic resonance imaging of the spine in the diagnosis of paediatric Guillain-Barre syndrome and compare it with nerve conduction studies and cerebrospinal fluid analysis. A retrospective review of investigations undertaken in children admitted to our institution with acute Guillain-Barre syndrome over a 10-year period was performed. Seven of eight children (88%) displayed post-gadolinium nerve root enhancement consistent with Guillain-Barre syndrome. This compared with supportive nerve conduction studies in 21/24 children (88%) and cerebrospinal fluid protein analysis consistent with the diagnosis in 16/20 children (80%). Nerve conduction studies are the recognised 'gold standard' technique for confirming a clinical diagnosis of Guillain-Barre syndrome. In this study, a high positive rate was demonstrated. While more experience is necessary, this study and the literature support gadolinium enhanced magnetic resonance imaging of the spine as a valuable, although not necessarily superior, investigation in the diagnosis of Guillain-Barre syndrome. It may be of particular benefit when specialist neurophysiology expertise is unavailable. © 2010 The Authors. Journal compilation © 2010 Paediatrics and Child Health Division (Royal Australasian College of Physicians).

  5. CALCIUM-RICH GAP TRANSIENTS: SOLVING THE CALCIUM CONUNDRUM IN THE INTRACLUSTER MEDIUM

    International Nuclear Information System (INIS)

    Mulchaey, John S.; Kollmeier, Juna A.; Kasliwal, Mansi M.

    2014-01-01

    X-ray measurements suggest that the abundance of calcium in the intracluster medium is higher than can be explained using favored models for core-collapse and Type Ia supernovae alone. We investigate whether the ''calcium conundrum'' in the intracluster medium can be alleviated by including a contribution from the recently discovered subclass of supernovae known as calcium-rich gap transients. Although the calcium-rich gap transients make up only a small fraction of all supernovae events, we find that their high calcium yields are sufficient to reproduce the X-ray measurements found for nearby rich clusters. We find the χ 2 goodness-of-fit metric improves from 84 to 2 by including this new class. Moreover, calcium-rich supernovae preferentially occur in the outskirts of galaxies making it easier for the nucleosynthesis products of these events to be incorporated in the intracluster medium via ram-pressure stripping. The discovery of calcium-rich gap transients in clusters and groups far from any individual galaxy suggests that supernovae associated with intracluster stars may play an important role in enriching the intracluster medium. Calcium-rich gap transients may also help explain anomalous calcium abundances in many other astrophysical systems including individual stars in the Milky Way, the halos of nearby galaxies, and the circumgalactic medium. Our work highlights the importance of considering the diversity of supernovae types and corresponding yields when modeling the abundance of the intracluster medium and other gas reservoirs

  6. Estimation of ionized calcium, total calcium and albumin corrected calcium for the diagnosis of hypocalcaemia of malignancy

    International Nuclear Information System (INIS)

    Ijaz, A.; Mehmood, T.; Qureshi, A.H.; Anwar, M.; Dilawar, M.; Hussain, I.; Khan, F.A.; Khan, D.A.; Hussain, S.; Khan, I.A.

    2006-01-01

    Objective: To measure levels of ionized calcium, total calcium and albumin corrected calcium in patients with different malignant disorders for the diagnosis of hypercalcaemia of malignancy. Design: A case control comparative study. Place and Duration of Study: The study was carried out in the Department of Pathology, Army Medical College Rawalpindi, Armed Forces Institute of Pathology and Department of Oncology CMH, Rawalpindi from March 2003 to December 2003. Subjects and Methods: Ninety-seven patients of various malignant disorders, admitted in the Department of Oncology, CMH, Rawalpindi, and 39 age and gender-matched disease-free persons (as control) were included in the study. Blood ionized calcium (Ca/sup ++/), pH, sodium (Na/sup +/) and potassium (K/sup +/) were analysed by Ion selective electrode (ISE) on Easylyte> auto analyser. Other related parameters were measured by colorimetric methods. Results: Blood Ca/sup ++/ levels in patients suffering from malignant disorders were found significantly high (mean +- j 1.30+017 mmoV/L) as compared to control subjects (mean +- 1.23+0.03 mmoV/L) (p<0.001). The number of patients with hypercalcaemia of malignancy detected by Ca/sup ++/ estimation was significantly higher (38%) as compared to total calcium (8.4%) and albumin corrected calcium ACC (10.6%) (p<0.001). There was no statistically significant difference in other parameters e.g. phosphate, urea, creatinine, pH, Na/sup +/ and K/sup +/ levels in study subjects and controls. Conclusion: Detection of hypercalcaemia can be markedly improved if ionized calcium estimation is used in patients with malignant disorders. (author)

  7. SR calcium handling and calcium after-transients in a rabbit model of heart failure

    NARCIS (Netherlands)

    Baartscheer, Antonius; Schumacher, Cees A.; Belterman, Charly N. W.; Coronel, Ruben; Fiolet, Jan W. T.

    2003-01-01

    Objective: After-depolarization associated arrhythmias are frequently observed in heart failure and associated with spontaneous calcium release from sarcoplasmic reticulum (SR), calcium after-transients. We hypothesize that disturbed SR calcium handling underlies calcium after-transients in heart

  8. Serial MRI studies using gadolinium DTPA in active multiple sclerosis

    International Nuclear Information System (INIS)

    Miller, D.H.; Johnson, G.; Barnes, D.; Rudge, P.; McDonald, W.I.

    1988-01-01

    It has been suggested that blood brain barrier (BBB) impairment is a necessary early event in the pathogenesis of the multiple sclerosis (MS) lesions. To evaluate such an hypothesis in vivo would require: (1) serial imaging studies using a modality with high sensitivity for detecting plaques; (2) a contrast enhancing agent which demonstrates BBB impairment. A serial magnetic resonance imaging (MRI) study was undertaken of a group of MS patients using the contrast agent gadolinium-DTPA. As it has been suggested that T 1 and T 2 relaxation times are longer in acute than chronic MS lesions, these were also measured. 3 refs.; 1 figure

  9. Calcium absorption from fortified ice cream formulations compared with calcium absorption from milk.

    Science.gov (United States)

    van der Hee, Regine M; Miret, Silvia; Slettenaar, Marieke; Duchateau, Guus S M J E; Rietveld, Anton G; Wilkinson, Joy E; Quail, Patricia J; Berry, Mark J; Dainty, Jack R; Teucher, Birgit; Fairweather-Tait, Susan J

    2009-05-01

    Optimal bone mass in early adulthood is achieved through appropriate diet and lifestyle, thereby protecting against osteoporosis and risk of bone fracture in later life. Calcium and vitamin D are essential to build adequate bones, but calcium intakes of many population groups do not meet dietary reference values. In addition, changes in dietary patterns are exacerbating the problem, thereby emphasizing the important role of calcium-rich food products. We have designed a calcium-fortified ice cream formulation that is lower in fat than regular ice cream and could provide a useful source of additional dietary calcium. Calcium absorption from two different ice cream formulations was determined in young adults and compared with milk. Sixteen healthy volunteers (25 to 45 years of age), recruited from the general public of The Netherlands, participated in a randomized, reference-controlled, double-blind cross-over study in which two test products and milk were consumed with a light standard breakfast on three separate occasions: a standard portion of ice cream (60 g) fortified with milk minerals and containing a low level (3%) of butter fat, ice cream (60 g) fortified with milk minerals and containing a typical level (9%) of coconut oil, and reduced-fat milk (1.7% milk fat) (200 mL). Calcium absorption was measured by the dual-label stable isotope technique. Effects on calcium absorption were evaluated by analysis of variance. Fractional absorption of calcium from the 3% butterfat ice cream, 9% coconut oil ice cream, and milk was 26%+/-8%, 28%+/-5%, and 31%+/-9%, respectively, and did not differ significantly (P=0.159). Results indicate that calcium bioavailability in the two calcium-fortified ice cream formulations used in this study is as high as milk, indicating that ice cream may be a good vehicle for delivery of calcium.

  10. Uptake of radiactive calcium by groundnut (Arachis hypogaea L. ) and efficiency of utilisation of applied calcium

    Energy Technology Data Exchange (ETDEWEB)

    Loganathan, S; Krishnamoorthy, K K [Tamil Nadu Agricultural Univ., Coimbatore (India). Dept. of Soil Science and Agricultural Chemistry

    1977-04-01

    A pot experiment was conducted with groundnut applying labelled calcium as its sulphate and carbonate at two levels namely 75 and 150 kg Ca per ha with varying levels of P, K and Mg. Plant samples were taken at different stages of crop growth and analysed for the content of radioactive calcium. Calcium sulphate treatment has resulted in larger uptake of calcium compared to calcium carbonate. An application of 150 kg Ca per ha has caused significantly higher uptake by groundnut plant than 75 kg Ca per ha. The percentage of utilisation of added calcium ranged from 2.2 to 5.4 Recovery of calcium by plants was more in calcium sulphate treatment rather than in calcium carbonate. The plants showed a preference for absorbing applied calcium rather than native calcium.

  11. Uptake of radiactive calcium by groundnut (Arachis hypogaea L.) and efficiency of utilisation of applied calcium

    International Nuclear Information System (INIS)

    Loganathan, S.; Krishnamoorthy, K.K.

    1977-01-01

    A pot experiment was conducted with groundnut applying labelled calcium as its sulphate and carbonate at two levels namely 75 and 150 kg Ca per ha with varying levels of P, K and Mg. Plant samples were taken at different stages of crop growth and analysed for the content of radioactive calcium. Calcium sulphate treatment has resulted in larger uptake of calcium compared to calcium carbonate. An application of 150 kg Ca per ha has caused significantly higher uptake by groundnut plant than 75 kg Ca per ha. The percentage of utilisation of added calcium ranged from 2.2 to 5.4 Recovery of calcium by plants was more in calcium sulphate treatment rather than in calcium carbonate. The plants showed a preference for absorbing applied calcium rather than native calcium

  12. Calcium in plant cells

    Directory of Open Access Journals (Sweden)

    V. V. Schwartau

    2014-04-01

    Full Text Available The paper gives the review on the role of calcium in many physiological processes of plant organisms, including growth and development, protection from pathogenic influences, response to changing environmental factors, and many other aspects of plant physiology. Initial intake of calcium ions is carried out by Ca2+-channels of plasma membrane and they are further transported by the xylem owing to auxins’ attractive ability. The level of intake and selectivity of calcium transport to ove-ground parts of the plant is controlled by a symplast. Ca2+enters to the cytoplasm of endoderm cells through calcium channels on the cortical side of Kaspary bands, and is redistributed inside the stele by the symplast, with the use of Ca2+-АТPases and Ca2+/Н+-antiports. Owing to regulated expression and activity of these calcium transporters, calclum can be selectively delivered to the xylem. Important role in supporting calcium homeostasis is given to the vacuole which is the largest depo of calcium. Regulated quantity of calcium movement through the tonoplast is provided by a number of potential-, ligand-gated active transporters and channels, like Ca2+-ATPase and Ca2+/H+ exchanger. They are actively involved in the inactivation of the calcium signal by pumping Ca2+ to the depo of cells. Calcium ATPases are high affinity pumps that efficiently transfer calcium ions against the concentration gradient in their presence in the solution in nanomolar concentrations. Calcium exchangers are low affinity, high capacity Ca2+ transporters that are effectively transporting calcium after raising its concentration in the cell cytosol through the use of protons gradients. Maintaining constant concentration and participation in the response to stimuli of different types also involves EPR, plastids, mitochondria, and cell wall. Calcium binding proteins contain several conserved sequences that provide sensitivity to changes in the concentration of Ca2+ and when you

  13. Magnetic resonance arthrography of the shoulder: accuracy of gadolinium versus saline for rotator cuff and labral pathology

    Energy Technology Data Exchange (ETDEWEB)

    Helms, Clyde A.; McGonegle, Shane J.; Vinson, Emily N.; Whiteside, Michael B. [Duke University Medical Center, Department of Radiology, Durham, NC (United States)

    2011-02-15

    The purpose of this study was to evaluate the necessity of intra-articular gadolinium versus saline alone in magnetic resonance arthrography (MRA) of the shoulder. Our database was reviewed for 100 consecutive shoulder MRA examinations performed between January 2007 and December 2007. Patient information was blinded and images were retrospectively reviewed by at least two radiologists with dedicated musculoskeletal training. T2-weighted (T2W) images were initially analyzed in isolation to simulate MRA with saline alone. After a delay, the full study was analyzed including T1-weighted (T1W) and T2W images. If there was a significant discordance between the two analyses with regard to rotator cuff or labral pathology, the study was again reviewed by all evaluators in consensus to determine if the T1W images offered additional diagnostic information and increased diagnostic confidence. Of the 100 MRA examinations, there were 15 discordant cases. Two cases were discordant with regard to rotator cuff pathology and 13 were discordant on the basis of labral pathology. When the discordant cases were reviewed in consensus, the T2W images appeared to display rotator cuff and labral pathology as definitively as the T1W images. Interobserver and intraobserver variability was favored to have played a role in causing the discordances. MRA of the shoulder performed with joint distention provided by saline alone appears to offer equivalent diagnostic information to MRA performed with gadolinium enhancement. This protocol modification improves efficiency by eliminating several image series and provides a small cost savings by eliminating gadolinium. (orig.)

  14. Magnetic resonance arthrography of the shoulder: accuracy of gadolinium versus saline for rotator cuff and labral pathology

    International Nuclear Information System (INIS)

    Helms, Clyde A.; McGonegle, Shane J.; Vinson, Emily N.; Whiteside, Michael B.

    2011-01-01

    The purpose of this study was to evaluate the necessity of intra-articular gadolinium versus saline alone in magnetic resonance arthrography (MRA) of the shoulder. Our database was reviewed for 100 consecutive shoulder MRA examinations performed between January 2007 and December 2007. Patient information was blinded and images were retrospectively reviewed by at least two radiologists with dedicated musculoskeletal training. T2-weighted (T2W) images were initially analyzed in isolation to simulate MRA with saline alone. After a delay, the full study was analyzed including T1-weighted (T1W) and T2W images. If there was a significant discordance between the two analyses with regard to rotator cuff or labral pathology, the study was again reviewed by all evaluators in consensus to determine if the T1W images offered additional diagnostic information and increased diagnostic confidence. Of the 100 MRA examinations, there were 15 discordant cases. Two cases were discordant with regard to rotator cuff pathology and 13 were discordant on the basis of labral pathology. When the discordant cases were reviewed in consensus, the T2W images appeared to display rotator cuff and labral pathology as definitively as the T1W images. Interobserver and intraobserver variability was favored to have played a role in causing the discordances. MRA of the shoulder performed with joint distention provided by saline alone appears to offer equivalent diagnostic information to MRA performed with gadolinium enhancement. This protocol modification improves efficiency by eliminating several image series and provides a small cost savings by eliminating gadolinium. (orig.)

  15. Characterization of composite metal-ceramic of nickel-oxide cerium doped gadolinium; Caracterizacao de compositos ceramica-metal de niquel e oxido de cerio dopado com gadolinio

    Energy Technology Data Exchange (ETDEWEB)

    Silva, M.L.A. da, E-mail: maria.andrade@pro.unifacs.br [Universidade Salvador (UNIFACS), BA (Brazil). Escola de Engenharia, Arquitetura e TI; Universidade Federal da Bahia (UFBA), BA (Brazil); Varela, M.C.R.S. [Universidade Federal da Bahia (UFBA), BA (Brazil)

    2016-07-01

    Composite nickel doped cerium oxide are used in SOFC anode materials. In this study we evaluated the effect of the presence of gadolinium on the properties of composite nickel and ceria and. The supports were synthesized by sol-gel method. The impregnation with nickel nitrate was taken sequentially, followed by calcination. The materials were characterized by X-ray diffraction, measurement of specific surface area, temperature programmed reduction, Raman spectroscopy. The presence of gadolinium retained the fluorite structure of ceria by forming a solid solution, also not influencing significantly on the specific surface area of the support. On the other hand, there was a decrease in the area catalysts, which can be attributed to sintering of nickel. Furthermore, addition of gadolinium favored the formation of intrinsic and extrinsic vacancies in cerium oxide, which leads to an increase in the ionic conductivity of the solid, desirable property for an SOFC anode catalyst. (author)

  16. Hyperintense hepatocellular carcinoma on gadolinium-enhanced hepatic MRI

    International Nuclear Information System (INIS)

    Yoshikawa, Jun; Matsui, Osamu; Kadoya, Masumi; Gabata, Toshifumi; Arai, Kazunori; Takashima, Tsutomu

    1992-01-01

    We reported a phenomenon in which some hepatocellular carcinomas (HHCs) visualized as hypointense on plain T1 weighted MR images became hyperintense on gadolinium-DTPA (Gd-DTPA) (0.06∼0.23 mmol/kg) enhanced delayed images. Gd-DTPA enhanced images (using a super conducting magnet operating at 1.5T) of 44 HCCs were studied in comparison with contrast enhanced CT using 30∼80g of iodine. Six of 44 HCCs (14%) which were visualized as hypointense on plain T1 weighted image became hyperintense on delayed Gd-DTPA enhanced images. Although these were visualized as low intensity areas on both plain and enhanced CT, the contrast between HCC and the surrounding liver was small on post contrast CT. These findings were thought to be due to a stronger enhancement effect of Gd-DTPA than that of iodine. (author)

  17. An Exploration of the Calcium-Binding Mode of Egg White Peptide, Asp-His-Thr-Lys-Glu, and In Vitro Calcium Absorption Studies of Peptide-Calcium Complex.

    Science.gov (United States)

    Sun, Na; Jin, Ziqi; Li, Dongmei; Yin, Hongjie; Lin, Songyi

    2017-11-08

    The binding mode between the pentapeptide (DHTKE) from egg white hydrolysates and calcium ions was elucidated upon its structural and thermodynamics characteristics. The present study demonstrated that the DHTKE peptide could spontaneously bind calcium with a 1:1 stoichiometry, and that the calcium-binding site corresponded to the carboxyl oxygen, amino nitrogen, and imidazole nitrogen atoms of the DHTKE peptide. Moreover, the effect of the DHTKE-calcium complex on improving the calcium absorption was investigated in vitro using Caco-2 cells. Results showed that the DHTKE-calcium complex could facilitate the calcium influx into the cytosol and further improve calcium absorption across Caco-2 cell monolayers by more than 7 times when compared to calcium-free control. This study facilitates the understanding about the binding mechanism between peptides and calcium ions as well as suggests a potential application of egg white peptides as nutraceuticals to improve calcium absorption.

  18. Evaluation of Novel 64Cu-Labeled Theranostic Gadolinium-Based Nanoprobes in HepG2 Tumor-Bearing Nude Mice

    Science.gov (United States)

    Hu, Pengcheng; Cheng, Dengfeng; Huang, Tao; Banizs, Anna B.; Xiao, Jie; Liu, Guobing; Chen, Quan; Wang, Yuenan; He, Jiang; Shi, Hongcheng

    2017-09-01

    Radiation therapy of liver cancer is limited by low tolerance of the liver to radiation. Radiosensitizers can effectively reduce the required radiation dose. AGuIX nanoparticles are small, multifunctional gadolinium-based nanoparticles that can carry radioisotopes or fluorescent markers for single-photon emission computed tomography (SPECT), positron emission tomography (PET), fluorescence imaging, and even multimodality imaging. In addition, due to the high atomic number of gadolinium, it can also serve as a tumor radiation sensitizer. It is critical to define the biodistribution and pharmacokinetics of these gadolinium-based nanoparticles to quantitate the magnitude and duration of their retention within the tumor microenvironment during radiotherapy. Therefore, in this study, we successfully labeled AGuIX with 64Cu through the convenient built-in chelator. The biodistribution studies indicated that the radiotracer 64Cu-AGuIX accumulates to high levels in the HepG2 xenograft of nude mice, suggesting that it would be a potential theranostic nanoprobe for image-guided radiotherapy in HCC. We also used a transmission electron microscope to confirm AGuIX uptake in the HepG2 cells. In radiation therapy studies, a decrease in 18F-FDG uptake was observed in the xenografts of the nude mice irradiated with AGuIX, which was injected 1 h before. These results provide proof-of-concept that AGuIX can be used as a theranostic radiosensitizer for PET imaging to guide radiotherapy for liver cancer.

  19. First results on study of gadolinium as burnable absorber

    International Nuclear Information System (INIS)

    Abbate, Maximo J.; Sbaffoni, Maria M.

    2000-01-01

    Following on with the work included in the 'Burnable absorbers research plan' several experiments were carried out oriented to determine Ga 2 O 3 burn up. Cold tests were performed and samples were irradiated in the RA-3 reactor. In this paper, some calculated values are presented together with their comparisons with experimental ones. The parameters foreseen for performing the experiments were verified and also the predictions on burn up of uranium and gadolinium isotopes concentrations. These results imply that the nuclear data of these isotopes included in the library are satisfactory. Next steps will be to measure other isotopes concentrations, gamma spectrum, and the irradiation of one pellet to determine self shielding effects in order to obtain effective cross sections i.e. for CAREM geometry. (author)

  20. Incidence of immediate adverse effects of gadolinium contrast media

    International Nuclear Information System (INIS)

    Ujita, Kouishi; Matsui, Satomi; Oikawa, Satoko; Habano, Youji; Ozaki, Daisuke; Ootake, Hidenori; Amanuma, Makoto; Endo, Keigo

    2010-01-01

    We investigated the adverse effects of intravenous injection of one of 4 types of gadolinium contrast media in 6550 patients: gadopentate dimeglumine (Gd-DTPA), 4299 patients; gadodiamide (Gd-DTPA-BMA), 1612; gadoteridol (Gd (HP-DO3A)), 565; and gadoterate meglumin (Gd-DOTA), 74. Thirty-two (0.49%) patients experienced adverse effects, which included rash (18.8%), nausea (40.6%), vomiting (34.4%), and an unpleasant sensation in the throat (6.3%). No patient required hospitalization. We compared the incidence of adverse effects from the 4 types of contrast media and found no difference in sex, age, body region examined, or method of contrast administration. Incidence was significantly higher for Gd (HP-DO3A) than Gd-DTPA and Gd-DTPA-BMA (P<0.000001). (author)

  1. Oral calcium carbonate affects calcium but not phosphorus balance in stage 3–4 chronic kidney disease

    Science.gov (United States)

    Hill, Kathleen M.; Martin, Berdine R.; Wastney, Meryl; McCabe, George P.; Moe, Sharon M.; Weaver, Connie M.; Peacock, Munro

    2014-01-01

    Chronic kidney disease (CKD) patients are given calcium carbonate to bind dietary phosphorus and reduce phosphorus retention, and to prevent negative calcium balance. Data are limited on calcium and phosphorus balance in CKD to support this. The aim of this study was to determine calcium and phosphorus balance and calcium kinetics with and without calcium carbonate in CKD patients. Eight stage 3/4 CKD patients, eGFR 36 mL/min, participated in two 3-week balances in a randomized placebo-controlled cross-over study of calcium carbonate (1500 mg/d calcium). Calcium and phosphorus balance were determined on a controlled diet. Oral and intravenous 45calcium with blood sampling and urine and fecal collections were used for calcium kinetics. Fasting blood and urine were collected at baseline and end of each week of each balance period for biochemical analyses. Results showed that patients were in neutral calcium and phosphorus balance while on placebo. Calcium carbonate produced positive calcium balance, did not affect phosphorus balance, and produced only a modest reduction in urine phosphorus excretion compared with placebo. Calcium kinetics demonstrated positive net bone balance but less than overall calcium balance suggesting tissue deposition. Fasting biochemistries of calcium and phosphate homeostasis were unaffected by calcium carbonate. If they can be extrapolated to effects of chronic therapy, these data caution against the use of calcium carbonate as a phosphate binder. PMID:23254903

  2. Neutron detector with own power supply, with an emitter made of gadolinium foil and two concentric collectors

    International Nuclear Information System (INIS)

    Brixy, H.; Spillekothen, H.G.; Benninghofen, G.; Serafin, N.

    1985-01-01

    The emitter consists of a material with a high absorption crossection for thermal neutrons, particularly gadolinium, and is provided with an auxiliary emitter layer on the inside and/or the outside. This increases the electron yield with suitable dimensions and material. (orig./HP) [de

  3. Calcium carbonate scaling kinetics determined from radiotracer experiments with calcium-47

    International Nuclear Information System (INIS)

    Turner, C.W.; Smith, D.W.

    1998-01-01

    The deposition rate of calcium carbonate on a heat-transfer surface has been measured using a calcium-47 radiotracer and compared to the measured rate of thermal fouling. The crystalline phase of calcium carbonate that precipitates depends on the degree of supersaturation at the heat-transfer surface, with aragonite precipitating at higher supersaturations and calcite precipitating at lower supersaturations. Whereas the mass deposition rates were constant with time, the thermal fouling rates decreased throughout the course of each experiment as a result of densification of the deposit. It is proposed that the densification was driven by the temperature gradient across the deposit together with the retrograde solubility of calcium carbonate. The temperature dependence of the deposition rate yielded an activation energy of 79 ± 4 kJ/mol for the precipitation of calcium carbonate on a heat-transfer surface. (author)

  4. Calcium Signaling in Taste Cells

    Science.gov (United States)

    Medler, Kathryn F.

    2014-01-01

    The sense of taste is a common ability shared by all organisms and is used to detect nutrients as well as potentially harmful compounds. Thus taste is critical to survival. Despite its importance, surprisingly little is known about the mechanisms generating and regulating responses to taste stimuli. All taste responses depend on calcium signals to generate appropriate responses which are relayed to the brain. Some taste cells have conventional synapses and rely on calcium influx through voltage-gated calcium channels. Other taste cells lack these synapses and depend on calcium release to formulate an output signal through a hemichannel. Beyond establishing these characteristics, few studies have focused on understanding how these calcium signals are formed. We identified multiple calcium clearance mechanisms that regulate calcium levels in taste cells as well as a calcium influx that contributes to maintaining appropriate calcium homeostasis in these cells. Multiple factors regulate the evoked taste signals with varying roles in different cell populations. Clearly, calcium signaling is a dynamic process in taste cells and is more complex than has previously been appreciated. PMID:25450977

  5. Calcium Pyrophosphate Deposition (CPPD)

    Science.gov (United States)

    ... Patient / Caregiver Diseases & Conditions Calcium Pyrophosphate Deposition (CPPD) Calcium Pyrophosphate Deposition (CPPD) Fast Facts The risk of ... young people, too. Proper diagnosis depends on detecting calcium pyrophosphate crystals in the fluid of an affected ...

  6. Calcium and bones (image)

    Science.gov (United States)

    Calcium is one of the most important minerals for the growth, maintenance, and reproduction of the human ... body, are continually being re-formed and incorporate calcium into their structure. Calcium is essential for the ...

  7. Antenatal calcium intake in Malaysia.

    Science.gov (United States)

    Mahdy, Zaleha Abdullah; Basri, Hashimah; Md Isa, Zaleha; Ahmad, Shuhaila; Shamsuddin, Khadijah; Mohd Amin, Rahmah

    2014-04-01

    To determine the adequacy of antenatal calcium intake in Malaysia, and the influencing factors. A cross-sectional study was conducted among postnatal women who delivered in two tertiary hospitals. Data were collected from antenatal cards, hospital documents and diet recall on daily milk and calcium intake during pregnancy. SPSS version 19.0 was used for statistical analyses. A total of 150 women were studied. The total daily calcium intake was 834 ± 43 mg (mean ± standard error of the mean), but the calcium intake distribution curve was skewed to the right with a median intake of 725 mg daily. When calcium intake from milk and calcium supplements was excluded, the daily dietary calcium intake was only 478 ± 25 mg. Even with inclusion of milk and calcium supplements, more than a third (n=55 or 36.7%) of the women consumed less than 600 mg calcium in their daily diet. The adequacy of daily calcium intake was not influenced by maternal age, ethnicity, income or maternal job or educational status as well as parity. The daily dietary calcium intake of the Malaysian antenatal population is far from adequate without the addition of calcium supplements and milk. © 2013 The Authors. Journal of Obstetrics and Gynaecology Research © 2013 Japan Society of Obstetrics and Gynecology.

  8. Calcium channel blocker poisoning

    Directory of Open Access Journals (Sweden)

    Miran Brvar

    2005-04-01

    Full Text Available Background: Calcium channel blockers act at L-type calcium channels in cardiac and vascular smooth muscles by preventing calcium influx into cells with resultant decrease in vascular tone and cardiac inotropy, chronotropy and dromotropy. Poisoning with calcium channel blockers results in reduced cardiac output, bradycardia, atrioventricular block, hypotension and shock. The findings of hypotension and bradycardia should suggest poisoning with calcium channel blockers.Conclusions: Treatment includes immediate gastric lavage and whole-bowel irrigation in case of ingestion of sustainedrelease products. All patients should receive an activated charcoal orally. Specific treatment includes calcium, glucagone and insulin, which proved especially useful in shocked patients. Supportive care including the use of catecholamines is not always effective. In the setting of failure of pharmacological therapy transvenous pacing, balloon pump and cardiopulmonary by-pass may be necessary.

  9. The Hepatitis B Virus X Protein Elevates Cytosolic Calcium Signals by Modulating Mitochondrial Calcium Uptake

    Science.gov (United States)

    Yang, Bei

    2012-01-01

    Chronic hepatitis B virus (HBV) infections are associated with the development of hepatocellular carcinoma (HCC). The HBV X protein (HBx) is thought to play an important role in the development of HBV-associated HCC. One fundamental HBx function is elevation of cytosolic calcium signals; this HBx activity has been linked to HBx stimulation of cell proliferation and transcription pathways, as well as HBV replication. Exactly how HBx elevates cytosolic calcium signals is not clear. The studies described here show that HBx stimulates calcium entry into cells, resulting in an increased plateau level of inositol 1,4,5-triphosphate (IP3)-linked calcium signals. This increased calcium plateau can be inhibited by blocking mitochondrial calcium uptake and store-operated calcium entry (SOCE). Blocking SOCE also reduced HBV replication. Finally, these studies also demonstrate that there is increased mitochondrial calcium uptake in HBx-expressing cells. Cumulatively, these studies suggest that HBx can increase mitochondrial calcium uptake and promote increased SOCE to sustain higher cytosolic calcium and stimulate HBV replication. PMID:22031934

  10. Liver acquisition with acceleration volume acquisition gadolinium-enhanced magnetic resonance combined with T2 sequences in the diagnosis of local recurrence of rectal cancer.

    Science.gov (United States)

    Cao, Wuteng; Li, Fangqian; Gong, Jiaying; Liu, Dechao; Deng, Yanhong; Kang, Liang; Zhou, Zhiyang

    2016-11-22

    To investigate the efficacy of liver acquisition with acceleration volume acquisition (LAVA) gadolinium-enhanced magnetic resonance (MR) sequences and to assess its added accuracy in diagnosing local recurrence (LR) of rectal cancer with conventional T2-weighted fast spin echo (FSE) sequences. Pelvic MRI, including T2-weighted FSE sequences, gadolinium-enhanced sequences of LAVA and T1-weighted FSE with fat suppression, was performed on 225 patients with postoperative rectal cancer. Two readers evaluated the presence of LR according to "T2" (T2 sequences only), "T2 + LAVA-Gad" (LAVA and T2 imaging), and "T2 + T1-fs-Gad" (T1 fat suppression-enhanced sequence with T2 images). To evaluate diagnostic efficiency, imaging quality with LAVA and T1-fs-Gad by subjective scores and the signal intensity (SI) ratio. In the result, the SI ratio of LAVA was significantly higher than that of T1-fs-Gad (p = 0.0001). The diagnostic efficiency of "T2 + LAVA-Gad" was better than that of "T2 + T1-fs-Gad" (p = 0.0016 for Reader 1, p = 0.0001 for Reader 2) and T2 imaging only (p = 0.0001 for Reader 1; p = 0.0001 for Reader 2). Therefore, LAVA gadolinium-enhanced MR increases the accuracy of diagnosis of LR from rectal cancer and could replace conventional T1 gadolinium-enhanced sequences in the postoperative pelvic follow-up of rectal cancer.

  11. Effect of anions or foods on absolute bioavailability of calcium from calcium salts in mice by pharmacokinetics

    OpenAIRE

    Zenei Taira, Zenei; Ueda,Yukari

    2013-01-01

    Yukari Ueda, Zenei TairaFaculty of Pharmaceutical Sciences, Tokushima Bunri University, Tokushima, JapanAbstract: We studied the absolute bioavailability of calcium from calcium L-lactate in mice using pharmacokinetics, and reviewed the absolute bioavailability of calcium from three other calcium salts in mice previously studied: calcium chloride, calcium acetate, and calcium ascorbate. The results showed that calcium metabolism is linear between intravenous administration of 15 mg/kg and 30 ...

  12. Differentiation between benign and malignant colon tumors using fast dynamic gadolinium-enhanced MR colonography; a feasibility study

    DEFF Research Database (Denmark)

    Achiam, M P; Andersen, L P H; Klein, M

    2010-01-01

    Colorectal cancer will present itself as a bowel obstruction in 16-23% of all cases. However, not all obstructing tumors are malignant and the differentiation between a benign and a malignant tumor can be difficult. The purpose of our study was to determine whether fast dynamic gadolinium...

  13. Gadolinium-DTPA in magnetic resonance tomography

    International Nuclear Information System (INIS)

    Prayer, L.; Imhof, H.; Stiglbauer, R.; Kramer, J.; Wimberger, D.

    1989-01-01

    Magnetic resonance tomography was performed on 158 patients with different indications before and after the administration of contrast medium. The MR examination included various plain T 1 and T 2 weighted spin echo sequences as well as T 1 weighted examinations after intravenous application of gadolinium-DTPA ('Magnevist', Schering AG) in a dosage of 0.1 mmol/kg body weight. The following conclusions were drawn: The sensitivity of MR in detecting brain tumors, acoustic neuromas and pituitary adenomas was improved considerably after the administration of 'Magnevist'. To diagnose the type of tumor, the criteria which apply to Gd-DPTA are similar to those used for iodine-containing contrast medium in CT. In about 2/3 rds of the cases, delineation of pathological tissues from surrounding edema and normal structures was better than in plain films. Hence, accurate, pretherapeutic staging of bronchial carcinomas and an exact definition of the expansion of the malignancies in the muscle-skeleton system were possible. In respect of tumors in the region of the base of the skull, we could omit T 2 -weighted sequences without noticeable loss of diagnostically relevant information; the examination time could thus be shortened by about 12 minutes. (orig.) [de

  14. Voltage-Gated Calcium Channels

    Science.gov (United States)

    Zamponi, Gerald Werner

    Voltage Gated Calcium Channels is the first comprehensive book in the calcium channel field, encompassing over thirty years of progress towards our understanding of calcium channel structure, function, regulation, physiology, pharmacology, and genetics. This book balances contributions from many of the leading authorities in the calcium channel field with fresh perspectives from risings stars in the area, taking into account the most recent literature and concepts. This is the only all-encompassing calcium channel book currently available, and is an essential resource for academic researchers at all levels in the areas neuroscience, biophysics, and cardiovascular sciences, as well as to researchers in the drug discovery area.

  15. Structural study of some gadolinium glass ceramics obtained by sol-gel method

    International Nuclear Information System (INIS)

    Coroiu, Ilioara; Simiti, Vida I.; Bratu, I.; Borodi, Gh.; Darabont, Al.

    2004-01-01

    Increased interest in silicate systems containing different rare earth oxides has resulted from their important applications in various fields of technology including laser, optical fiber and optical waveguides in telecommunication applications, microelectronics and catalysis. Glass-ceramics of 0.95 SiO 2 -0.05 Na 2 O composition containing up to 15% molar Gd 2 O 3 were obtained by the sol-gel method. We chose the sol-gel method because this offers the advantage of a good chemical homogeneity and a better control of physical and chemical properties in comparison with traditional methods used to obtain glasses and ceramics. The obtained samples were pressed at 200 kgf/cm 2 as disks with a diameter of Φ=22 mm and a thickness of around 1 mm. Then, they were heat-treated at 250 deg C, 500 deg C and 1000 deg C for about 48 hours. The structural study was made using X-ray diffraction, scanning electron microscopy (SEM) and IR spectroscopy. The X-ray diffraction patterns show that addition of Gd 2 O 3 exerts an important influence on the crystallization process of the studied samples. The crystalline phase decreases with increasing the Gd 2 O 3 concentration. SEM data support this assertion. IR spectra point out also that the increasing of the gadolinium oxide content and the thermal treatment temperature produce the strengthening of the glass ceramic network. Thus, the gadolinium ions play the role of network modifier of the glass ceramic structure. (authors)

  16. The influence of calcium-45 on the inhibitive effect of calcium hexameta-phosphate combination and the electrocapillary effect of calcium-45

    International Nuclear Information System (INIS)

    Subramanyan, N.; Venkatakrishna Iyer, S.; Kapali, V.

    1978-01-01

    Corrosion of steel in an aqueous chloride solution is significantly accelerated if calcium (NaHMP)-45 is substituted for ordinary calcium when calcium and sodium metaphosphate combination was investigated for inhibiting action. In this investigation it is seen that the anodic polarisation of steel is brought down when 45 Ca is present in the different solutions containing Ca, non radioactive calcium and (NaHMP) at pH 5.5, 7.5 and 9.0 except in one case when 45 Ca is present alone in the solution of pH 5.5. The uptake of 45 Ca is more at the positive potentials than at the negative. Electrocapillary measurements with calcium chloride solution show that the electrocapillary curve is lifted above that for the base solution particularly on the positive side of the electrocapillary maximum. These interesting observations are explained by the postulate that radioactive calcium behaves like an anion and the acceleration of corrosion is attributed essentially to radiolytically produced hydrogen peroxide. (author)

  17. Calcium binding by dietary fibre

    International Nuclear Information System (INIS)

    James, W.P.T.; Branch, W.J.; Southgate, D.A.T.

    1978-01-01

    Dietary fibre from plants low in phytate bound calcium in proportion to its uronic-acid content. This binding by the non-cellulosic fraction of fibre reduces the availability of calcium for small-intestinal absorption, but the colonic microbial digestion of uronic acids liberates the calcium. Thus the ability to maintain calcium balance on high-fibre diets may depend on the adaptive capacity on the colon for calcium. (author)

  18. Dengue and Calcium

    OpenAIRE

    Shivanthan, Mitrakrishnan C; Rajapakse, Senaka

    2014-01-01

    Dengue is potentially fatal unless managed appropriately. No specific treatment is available and the mainstay of treatment is fluid management with careful monitoring, organ support, and correction of metabolic derangement. Evidence with regards to the role of calcium homeostasis in dengue is limited. Low blood calcium levels have been demonstrated in dengue infection and hypocalcemia maybe more pronounced in more severe forms. The cause of hypocalcemia is likely to be multifactorial. Calcium...

  19. Temperature profiles on the gadolinium surface during electron beam evaporation

    Energy Technology Data Exchange (ETDEWEB)

    Ohba, Hironori; Shibata, Takemasa [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1995-03-01

    The distributions of surface temperature of gadolinium in a water-cooled copper crucible during electron beam evaporation were measured by optical pyrometry. The surface temperatures were obtained from the radiation intensity ratio of the evaporating surface and a reference light source using Planck`s law of radiation. The emitted radiation from the evaporating surface and a reference source was detected by a CCD sensor through a band pass filter of 650 nm. The measured surface temperature generally agreed with those estimated from the deposition rate and the data of the saturated vapor pressure. At high input powers, it was found that the measured value had small difference with the estimated one due to variation of the surface condition. (author).

  20. Temperature profiles on the gadolinium surface during electron beam evaporation

    International Nuclear Information System (INIS)

    Ohba, Hironori; Shibata, Takemasa

    1995-01-01

    The distributions of surface temperature of gadolinium in a water-cooled copper crucible during electron beam evaporation were measured by optical pyrometry. The surface temperatures were obtained from the radiation intensity ratio of the evaporating surface and a reference light source using Planck's law of radiation. The emitted radiation from the evaporating surface and a reference source was detected by a CCD sensor through a band pass filter of 650 nm. The measured surface temperature generally agreed with those estimated from the deposition rate and the data of the saturated vapor pressure. At high input powers, it was found that the measured value had small difference with the estimated one due to variation of the surface condition. (author)

  1. Tracing the spatial propagation of river inlet water into an agricultural polder area using anthropogenic gadolinium

    Directory of Open Access Journals (Sweden)

    J. Rozemeijer

    2012-08-01

    Full Text Available Diverting river water into agricultural areas or nature reserves is a frequently applied management strategy to prevent fresh water shortage. However, the river water might have negative consequences for chemical and ecological water quality in the receiving water bodies. This study aimed to obtain a spatial image of the diverted river water propagation into a hydrologically complex polder area, the polder Quarles van Ufford in The Netherlands. We used anthropogenic gadolinium (Gd-anomaly as a tracer for river water that was diverted into the polder. A clear reduction in the river water contribution was found between very dry conditions on 5 August 2010 and very wet conditions on 22 October. Despite the large river water impact on 5 August, the diverted river water did not propagate up into the small agricultural headwater ditches. Gadolinium proved to be an effective tracer for diverted river water in a polder system. We applied our results to upgrade the interpretation of water quality monitoring data and to validate an integrated nutrient transport model.

  2. High temperature interaction studies on equimolar nitrate mixture of uranyl nitrate hexahydrate and gadolinium nitrate hexahydrate

    International Nuclear Information System (INIS)

    Kalekar, Bhupesh B.; Raje, Naina; Reddy, A.V.R.

    2015-01-01

    Rare earths including gadolinium form a sizeable fraction of the fission products in the nuclear fission of fissile material in the reactor. These fission products can interact with uranium dioxide fuel and can form various compounds which can alter the thermal behavior of the fuel. The mixed oxide formed due to the high temperature interactions of mixture of uranyl nitrate hexahydrate (UNH) and gadolinium nitrate hexahydrate (GdNH) has been studied using thermal and X- ray diffraction techniques. The equimolar mixture of UNH and GdNH was prepared by mixing the weighed amount of individual nitrates and grinding gently with mortar and pestle. Thermogravimetry (TG) measurements were carried out by separately heating 100 mg of mixture and individual nitrates at heating rate of 10°C min -1 using Netzsch thermal analyzer (Model No.: STA 409 PC Luxx) in high purity nitrogen atmosphere with a flow rate of 120 mL min -1 . The XRD measurement was carried out on a Philips X-ray diffractometer (Model PW1710) using nickel-filtered Cu-Kα radiation

  3. Combined use of contrast media containing iodine and gadolinium for imaging and intervention. A hitherto widely ignored topic in radiological practice

    International Nuclear Information System (INIS)

    Golder, W.

    2012-01-01

    The synchronous use of chemically different contrast media in the same body compartment is a challenge for the radiologist, whether it is scheduled or unexpected. However, to inject contrast media containing iodine and gadolinium at the same time can be a prerequisite for the examination of several organs or organ systems. Unlike other topics of contrast-enhanced imaging procedures, the difficulties encountered with double contrast injections have been widely ignored in the literature. In the absence of reliable data from experimental and clinical studies the radiologist is dependent on case reports, information provided by the contrast media manufacturers, personal communications, mostly scanty personal experiences and a skilful time management, in order to overcome the situation. Only the combination of X-ray, computed tomography and magnetic resonance arthrography can be performed without another thought. However, the more or less synchronous vascular application of contrast media containing iodine and gadolinium requires vigilance. The more seriously ill the patient is, the more caution is advised even if the decision on the combined administration has to be reached urgently. The following overview gives a description of the properties of contrast media containing iodine and gadolinium as far as interactions following simultaneous administration are concerned. Subsequently, the clinically relevant situations and constellations are outlined and analyzed. (orig.) [de

  4. Gadolinium-enhanced MRI features of acute gouty arthritis on top of chronic gouty involvement in different joints

    NARCIS (Netherlands)

    Emad, Yasser; Ragab, Yasser; El-Naggar, Ahmed; El Shaarawy, Nashwa; Abd-Allah, Mayada A.; Gamal, Rania M.; Fathy, Ahmed; Hawass, Mona; Rasker, Johannes J.

    2015-01-01

    The aims of the current study are to describe gadolinium-enhanced MRI features of an acute flare of established gouty arthritis in different joints and to examine a possible association between serum uric acid and MRI signs indicative of ongoing inflammation and/or structural joint damage as well as

  5. Differentiation between benign and malignant colon tumors using fast dynamic gadolinium-enhanced MR colonography; a feasibility study

    DEFF Research Database (Denmark)

    Achiam, M P; Andersen, L P H; Klein, M

    2010-01-01

    Colorectal cancer will present itself as a bowel obstruction in 16-23% of all cases. However, not all obstructing tumors are malignant and the differentiation between a benign and a malignant tumor can be difficult. The purpose of our study was to determine whether fast dynamic gadolinium-enhance...

  6. Rapid colorimetric sensing of gadolinium by EGCG-derived AgNPs: the development of a nanohybrid bioimaging probe.

    Science.gov (United States)

    Singh, Rohit Kumar; Mishra, Sourav; Jena, Satyapriya; Panigrahi, Bijayananda; Das, Bhaskar; Jayabalan, Rasu; Parhi, Pankaj Kumar; Mandal, Dindyal

    2018-04-17

    Polyphenol functionalized silver nanoparticles (AgNPs) have been developed and demonstrated as colorimetric sensors for the selective detection of gadolinium. The newly obtained AgNP-Gd3+ conjugates exhibit high aqueous dispersibility and excitation dependent fluorescence emission. The conjugates offer multicolor bioimaging potential owing to their excellent luminescence properties.

  7. Magnetically Active and Coated Gadolinium-Filled Carbon Nanotubes

    KAUST Repository

    Fidiani, Elok; Da Costa, Pedro M. F. J.; Wolter, Anja U. B.; Maier, Diana; Buechner, Bernd; Hampel, Silke

    2013-01-01

    Gd-filled carbon nanotubes (which include the so-called gadonanotubes(1)) have been attracting much interest due to their potential use in medical diagnostic applications. In the present work, a vacuum filling method was performed to confine gadolinium(III) iodide in carbon nanotubes (CNTs). Filling yields in excess of 50% were obtained. Cleaning and dosing of the external walls was undertaken, as well as the study of the filled CNT magnetic properties. Overall, we found that the encapsulating procedure can lead to reduction of the lanthanide metal and induce disorder in the initial GdI3-type structure. Notwithstanding, the magnetic response of the material is not compromised, retaining a strong paramagnetic response and an effective magnetic moment of similar to 6 mu B. Our results may entice further investigation into whether an analogous Gd3+ to Gd2+ reduction takes place in other Gd-filled CNT systems.

  8. Magnetically Active and Coated Gadolinium-Filled Carbon Nanotubes

    KAUST Repository

    Fidiani, Elok

    2013-08-15

    Gd-filled carbon nanotubes (which include the so-called gadonanotubes(1)) have been attracting much interest due to their potential use in medical diagnostic applications. In the present work, a vacuum filling method was performed to confine gadolinium(III) iodide in carbon nanotubes (CNTs). Filling yields in excess of 50% were obtained. Cleaning and dosing of the external walls was undertaken, as well as the study of the filled CNT magnetic properties. Overall, we found that the encapsulating procedure can lead to reduction of the lanthanide metal and induce disorder in the initial GdI3-type structure. Notwithstanding, the magnetic response of the material is not compromised, retaining a strong paramagnetic response and an effective magnetic moment of similar to 6 mu B. Our results may entice further investigation into whether an analogous Gd3+ to Gd2+ reduction takes place in other Gd-filled CNT systems.

  9. Synthesis of calcium hydroxyapatite from calcium carbonate and different orthophosphate sources: A comparative study

    International Nuclear Information System (INIS)

    Pham Minh, Doan; Lyczko, Nathalie; Sebei, Haroun; Nzihou, Ange; Sharrock, Patrick

    2012-01-01

    Highlights: ► Calcium hydroxyapatite was synthesized from CaCO 3 and four orthophosphates. ► Only H 3 PO 4 led to the complete precipitation of orthophosphate species. ► H 3 PO 4 was also the most efficient for calcium dissolution. ► Reaction pathway was dissolution-precipitation accompanied by agglomeration step. - Abstract: The synthesis of calcium hydroxyapatite (Ca-HA) starting from calcium carbonate and different orthophosphate sources, including orthophosphoric acid, potassium, sodium and ammonium dihydrogen orthophosphates, was investigated under ambient conditions. The reaction started with calcium carbonate dissolution in an acid medium, followed by rapid precipitation of calcium cations with orthophosphate species to form calcium phosphate based particles which were in the size range of 0.4–1 μm. These particles then agglomerated into much larger ones, up to 350 μm in diameter (aggregates). These aggregates possessed an unstable porous structure which was responsible for the porosity of the final products. The highest specific surface area and pore volume were obtained with potassium dihydrogen orthophosphate. On the other hand, orthophosphoric acid led to the highest dissolution of calcium carbonate and the complete precipitation of orthophosphate species. Under ambient conditions, calcium phosphate based solid products of low crystallinity were formed. Different intermediates were identified and a reaction pathway proposed.

  10. Testosterone increases urinary calcium excretion and inhibits expression of renal calcium transport proteins.

    NARCIS (Netherlands)

    Hsu, Y.J.; Dimke, H.; Schoeber, J.P.H.; Hsu, S.C.; Lin, S.H.; Chu, P.; Hoenderop, J.G.J.; Bindels, R.J.M.

    2010-01-01

    Although gender differences in the renal handling of calcium have been reported, the overall contribution of androgens to these differences remains uncertain. We determined here whether testosterone affects active renal calcium reabsorption by regulating calcium transport proteins. Male mice had

  11. Calcium metabolism in birds.

    Science.gov (United States)

    de Matos, Ricardo

    2008-01-01

    Calcium is one of the most important plasma constituents in mammals and birds. It provides structural strength and support (bones and eggshell) and plays vital roles in many of the biochemical reactions in the body. The control of calcium metabolism in birds is highly efficient and closely regulated in a number of tissues, primarily parathyroid gland, intestine, kidney, and bone. The hormones with the greatest involvement in calcium regulation in birds are parathyroid hormone, 1,25-dihydroxyvitamin D(3) (calcitriol), and estrogen, with calcitonin playing a minor and uncertain role. The special characteristics of calcium metabolism in birds, mainly associated with egg production, are discussed, along with common clinical disorders secondary to derangements in calcium homeostasis.

  12. Gadolinium(III-DOTA Complex Functionalized with BODIPY as a Potential Bimodal Contrast Agent for MRI and Optical Imaging

    Directory of Open Access Journals (Sweden)

    Matthias Ceulemans

    2015-11-01

    Full Text Available The synthesis and characterization of a novel gadolinium(III DOTA complex functionalized with a boron-dipyrromethene derivative (BODIPY is described. The assembly of the complex relies on azide diazotransfer chemistry in a copper tube flow reactor. The azide thus formed is coupled directly with an alkyne via click chemistry, resulting into a paramagnetic and luminescent gadolinium(III complex. Luminescent data and relaxometric properties of the complex have been evaluated, suggesting the potential applicability of the complexes as a bimodal contrast agent for magnetic resonance and optical imaging. The complex displays a bright emission at 523 nm with an absorption maximum of 507 nm and high quantum yields of up to 83% in water. The proton relaxivity of the complex measured at 310 K and at frequencies of 20 and 60 MHz had the values of 3.9 and 3.6 s−1·mM−1, respectively.

  13. Late gadolinium enhancement and adverse outcomes in a contemporary cohort of adult survivors of tetralogy of Fallot.

    Science.gov (United States)

    Dobson, Richard J; Mordi, Ify; Danton, Mark H; Walker, Niki L; Walker, Hamish A; Tzemos, Nikolaos

    2017-01-01

    Myocardial fibrosis has been associated with poorer outcomes in tetralogy of Fallot, however only a handful of studies have assessed its significance in the current era. Our aim was to quantify the amount of late gadolinium enhancement in both the LV and RV in a contemporary cohort of adults with surgically repaired tetralogy of Fallot, and assess the relationship with adverse clinical outcomes. Single centre cohort study SETTING: National tertiary referral center Patients: One hundred fourteen patients with surgically repaired tetralogy of Fallot with median age 29.5 years (range 17.5-64.2). Prospective follow-up for mean 2.4 years (SD 1.29). Cardiovascular magnetic resonance was performed, and late gadolinium enhancement mass was estimated for the LV using the 5-SD remote myocardium method, and for the RV using a segmental scoring system. Cohort characterization was determined through the use of a computerized database. Survival analysis from time of scan to first adverse event, defined as an episode of atrial arrhythmia, sustained ventricular arrhythmia, hospitalization with heart failure, or implantable cardioverter-defibrillator insertion. Eleven patients experienced an adverse outcome in the follow-up period, although there were no deaths. LV late gadolinium enhancement was associated with adverse outcomes in a univariate model (P = .027). However, when adjusted for age at scan the significant variables included NYHA class (P = .006), peak oxygen uptake (P = .028), number of prior sternotomies (P = .044), and higher indexed RV and LV end diastolic volumes (P = .002 and P tetralogy of Fallot survivors, however assessment particularly of the LV holds promise for the future. © 2016 Wiley Periodicals, Inc.

  14. A first principles kinetic Monte Carlo investigation of the adsorption and mobility of gadolinium on the (100) surface of tungsten

    International Nuclear Information System (INIS)

    Samin, Adib J.; Zhang, Jinsuo

    2017-01-01

    An accurate characterization of lanthanide adsorption and mobility on tungsten surfaces is important for pyroprocessing. In the present study, the adsorption and diffusion of gadolinium on the (100) surface of tungsten was investigated. It was found that the hollow sites were the most energetically favorable for the adsorption. It was further observed that a magnetic moment was induced following the adsorption of gadolinium on the tungsten surface and that the system with adsorbed hollow sites had the largest magnetization. A pathway for the surface diffusion of gadolinium was determined to occur by hopping between the nearest neighbor hollow sites via the bridge site and the activation energy for the hop was calculated to be 0.75 eV. The surface diffusion process was further assessed using two distinct kinetic Monte Carlo models; one that accounted for lateral adsorbate interactions up to the second nearest neighbor and one that did not account for such interatomic interactions in the adlayer. When the lateral interactions were included in the simulations, the diffusivity was observed to have a strong dependence on coverage (for the coverage values being studied). The effects of lateral interactions were further observed in a one-dimensional simulation of the diffusion equation where the asymmetry in the surface coverage profile upon its approach to a steady state distribution was clear in comparison with the simulations which did not account for those interactions.

  15. A first principles kinetic Monte Carlo investigation of the adsorption and mobility of gadolinium on the (100) surface of tungsten

    Energy Technology Data Exchange (ETDEWEB)

    Samin, Adib J., E-mail: samin.2@osu.edu; Zhang, Jinsuo

    2017-05-15

    An accurate characterization of lanthanide adsorption and mobility on tungsten surfaces is important for pyroprocessing. In the present study, the adsorption and diffusion of gadolinium on the (100) surface of tungsten was investigated. It was found that the hollow sites were the most energetically favorable for the adsorption. It was further observed that a magnetic moment was induced following the adsorption of gadolinium on the tungsten surface and that the system with adsorbed hollow sites had the largest magnetization. A pathway for the surface diffusion of gadolinium was determined to occur by hopping between the nearest neighbor hollow sites via the bridge site and the activation energy for the hop was calculated to be 0.75 eV. The surface diffusion process was further assessed using two distinct kinetic Monte Carlo models; one that accounted for lateral adsorbate interactions up to the second nearest neighbor and one that did not account for such interatomic interactions in the adlayer. When the lateral interactions were included in the simulations, the diffusivity was observed to have a strong dependence on coverage (for the coverage values being studied). The effects of lateral interactions were further observed in a one-dimensional simulation of the diffusion equation where the asymmetry in the surface coverage profile upon its approach to a steady state distribution was clear in comparison with the simulations which did not account for those interactions.

  16. Calcium Balance in Chronic Kidney Disease.

    Science.gov (United States)

    Hill Gallant, Kathleen M; Spiegel, David M

    2017-06-01

    The kidneys play a critical role in the balance between the internal milieu and external environment. Kidney failure is known to disrupt a number of homeostatic mechanisms that control serum calcium and normal bone metabolism. However, our understanding of calcium balance throughout the stages of chronic kidney disease is limited and the concept of balance itself, especially with a cation as complex as calcium, is often misunderstood. Both negative and positive calcium balance have important implications in patients with chronic kidney disease, where negative balance may increase risk of osteoporosis and fracture and positive balance may increase risk of vascular calcification and cardiovascular events. Here, we examine the state of current knowledge about calcium balance in adults throughout the stages of chronic kidney disease and discuss recommendations for clinical strategies to maintain balance as well as future research needs in this area. Recent calcium balance studies in adult patients with chronic kidney disease show that neutral calcium balance is achieved with calcium intake near the recommended daily allowance. Increases in calcium through diet or supplements cause high positive calcium balance, which may put patients at risk for vascular calcification. However, heterogeneity in calcium balance exists among these patients. Given the available calcium balance data in this population, it appears clinically prudent to aim for recommended calcium intakes around 1000 mg/day to achieve neutral calcium balance and avoid adverse effects of either negative or positive calcium balance. Assessment of patients' dietary calcium intake could further equip clinicians to make individualized recommendations for meeting recommended intakes.

  17. Gadolinium DTPA-monoamide complexes incorporated into mixed micelles as possible MRI contrast agents

    OpenAIRE

    Parac-Vogt, Tatjana; Kimpe, Kristof; Laurent, Sophie; Pierart, Corinne; Vander Elst, Luce; Muller, Robert N.; Binnemans, Koen

    2004-01-01

    Four monoamide derivatives of Gd-DTPA with alkyl chains consisting of 12, 14, 16, or 18 carbon atoms were synthesized. The gadolinium(III) complexes with chain lengths of 14, 16 or 18 carbon atoms were efficiently incorporated into mixed micelles whereas the complex with a chain length of 12 carbon atoms was not incorporated into a micellar structure. The size distribution of the micelles was measured by photon correlation spectroscopy. The mean sizes of the micelles for all the complexes lay...

  18. Extreme ultra-violet emission spectroscopy of highly charged gadolinium ions with an electron beam ion trap

    International Nuclear Information System (INIS)

    Ohashi, Hayato; Nakamura, Nobuyuki; Sakaue, Hiroyuki A

    2013-01-01

    We present extreme ultra-violet emission spectra of highly charged gadolinium ions obtained with an electron beam ion trap at electron energies of 0.53–1.51 keV. The electron energy dependence of the spectra in the 5.7–11.3 nm range is compared with calculation with the flexible atomic code. (paper)

  19. Evaluation of three-dimensional gadolinium-enhanced MR angiography using the timing monitoring function of contrast material (Smart Prep technique)

    International Nuclear Information System (INIS)

    Tsuchihashi, Toshio; Sasaki, Sadayuki; Yoshizawa, Satoshi; Maki, Toshio; Kitagawa, Matsuo; Suzuki, Takeshi

    1998-01-01

    The Smart Prep technique for gadolinium-enhanced three-dimensional MR angiography (3D-MRA) was evaluated in clinical practice. By monitoring signal intensity in the region of interest (tracking volume) in the target vessel, start timing after contrast injection can be optimized using the Smart Prep technique. Successful triggering was obtained in the chest, abdomen, and pelvic areas in about 80% of the cases in this study. Failures with this technique were mainly due to changes in tracking volume caused by patient motion and respiration. We noted that the scan started earlier than expected in the thoracic aorta when part of the heart or pulmonary artery was included in the tracking volume. Thus, care must be taken in defining the size and location of the tracking volume in gadolinium-enhanced 3D-MRA using the Smart Prep technique. (author)

  20. Fenoprofen calcium overdose

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/002649.htm Fenoprofen calcium overdose To use the sharing features on this page, please enable JavaScript. Fenoprofen calcium is a type of medicine called a nonsteroidal ...

  1. Effect of oral calcium and calcium + fluoride treatments on mouse bone properties during suspension

    Science.gov (United States)

    Simske, S. J.; Luttges, M. W.; Allen, K. A.; Spooner, B. S. (Principal Investigator)

    1992-01-01

    The bone effects of oral dosages of calcium chloride with or without supplementary sodium fluoride were assessed in antiorthostatically suspended mice. Two calcium dosages were used to replace half (3.1 mM) or all(6.3 mM) of the dietary calcium lost due to reduced food intake by the suspended mice. Two groups of 6.3 mM CaCl2-treated mice were additionally treated with 0.25 or 2.5 mM NaF. The results indicate that supplementation of the mouse drinking water with calcium salts prevents bone changes induced by short-term suspension, while calcium salts in combination with fluoride are less effective as fluoride dosage increases. However, the calcium supplements change the relationship between the femur mechanical properties and the mineral composition of the bone. Because of this, it appears that oral calcium supplements are effective through a mechanism other than simple dietary supplementation and may indicate a dependence of bone consistency on systemic and local fluid conditions.

  2. Delayed Gadolinium-Enhanced Magnetic Resonance Imaging (dGEMRIC) of Hip Joint Cartilage: Better Cartilage Delineation after Intra-Articular than Intravenous Gadolinium Injection

    DEFF Research Database (Denmark)

    Boesen, M.; Jensen, K.E.; Quistgaard, E.

    2006-01-01

    years) with clinical and radiographic hip osteoarthritis (OA; Kellgren score II-III), MRI of the hip was performed twice on a clinical 1.5T MR scanner: On day 1, before and 90-180 min after 0.3 mmol/kg body weight i.v. Gd-DTPA and, on day 8, 90-180 min after ultrasound-guided i.a. injection of a 4 mmol......PURPOSE: To investigate and compare delayed gadolinium (Gd-DTPA)-enhanced magnetic resonance imaging (MRI) of cartilage (dGEMRIC) in the hip joint using intravenous (i.v.) or ultrasound-guided intra-articular (i.a.) Gd-DTPA injection. MATERIAL AND METHODS: In 10 patients (50% males, mean age 58......) in the joint cartilage compared to the non-enhanced images (P I.a. Gd-DTPA provided significantly higher SNR and CNR compared to i.v. Gd-DTPA (P

  3. Synthesis and characterization of nano structures of Silica SBA-16 containing Gadolinium-159 as potential nanoparticulated system for cancer therapy

    International Nuclear Information System (INIS)

    Oliveira, Andre Felipe de

    2013-01-01

    Cancer is a leading cause of death worldwide, and malignant neoplasms of the lung, stomach, liver, colon and breast in greater numbers. And recently observed in the literature a large number of reviews where new materials, especially nanoparticle, has been studied as drug carriers and radioisotopes applied to cancer treatment. How mesoporous materials based on silica, thanks to its huge surface area and biocompatibility, have been studied intensively providing broad applications in various areas, the use of nanostructured silica SBA-16 might be a carrier specific radioisotope accumulate in the cells malignant. Thus the aim of this study is to develop in vitro studies using SBA-16 can selectively concentrate in malignant cells therapeutic amounts of the radioisotope Gadolinium-159 escorting them to death. This work was performed orderly synthesis of mesoporous silica, SBA-16 and incorporating the complex Gd-DTPA-BMA, as well as chemical and structural characterization. The techniques used to analyze the occurrence of the incorporation of the gadolinium complex in the silica matrix were elemental analysis (CHN), atomic emission spectroscopy (ICP-AES), infrared spectroscopy (FTIR), nitrogen adsorption (BET), small-angle X-ray scattering (SAXS) and thermogravimetric analysis (TG). To analyze the morphology of pure silica used the scanning electron microscopy (SEM) and transmission electron microscopy (TEM). By photon correlation spectroscopy (PCS) it was possible to obtain a measure of mean particle size, the polydispersity index (PDI) of the silica SBA-16, and the zeta potential by laser Doppler anemometry (LDA). The results of incorporation analyzed by ICP-AES indicated that the material SBA-16 had a higher rate of incorporation of gadolinium (93%). The release kinetics in simulated body fluid, showed considerable stability and low release (1%). The mesoporous silica SBA-16 showed cell viability in direct contact with cell culture. Samples with gadolinium

  4. Penetration and distribution of gadolinium-based contrast agents into the cerebrospinal fluid in healthy rats: a potential pathway of entry into the brain tissue.

    Science.gov (United States)

    Jost, Gregor; Frenzel, Thomas; Lohrke, Jessica; Lenhard, Diana Constanze; Naganawa, Shinji; Pietsch, Hubertus

    2017-07-01

    Signal hyperintensity on unenhanced MRI in certain brain regions has been reported after multiple administrations of some, but not all, gadolinium-based contrast agents (GBCAs). One potential initial pathway of GBCA entry into the brain, infiltration from blood into the cerebrospinal fluid (CSF), was systematically evaluated in this preclinical study. GBCA infiltration and distribution in the CSF were investigated in healthy rats using repeated fluid-attenuated MRI up to 4 h after high-dose (1.8 mmol/kg) administration of six marketed and one experimental GBCA. Additionally, gadolinium measurements in CSF, blood and brain tissue samples (after 24 h) were performed using inductively coupled plasma mass spectrometry. Enhanced MRI signals in the CSF spaces with similar distribution kinetics were observed for all GBCAs. No substantial differences in the gadolinium concentrations among the marketed GBCAs were found in the CSF, blood or brain tissue. After 4.5 h, the concentration in the CSF was clearly higher than in blood but was almost completely cleared and lower than the brain tissue concentration after 24 h. In contrast to the brain signal hyperintensities, no differences in penetration and distribution into the CSF of healthy rats exist among the marketed GBCAs. • Gadolinium-based contrast agents can cross the blood-CSF barrier. • Fluid-attenuated MRI shows GBCA distribution with CSF flow. • GBCA structure and physicochemical properties do not impact CSF penetration and distribution. • GBCA clearance from CSF was almost complete within 24 h in rats. • CSF is a potential pathway of GBCA entry into the brain.

  5. Structures of apicomplexan calcium-dependent protein kinases reveal mechanism of activation by calcium

    Energy Technology Data Exchange (ETDEWEB)

    Wernimont, Amy K; Artz, Jennifer D.; Jr, Patrick Finerty; Lin, Yu-Hui; Amani, Mehrnaz; Allali-Hassani, Abdellah; Senisterra, Guillermo; Vedadi, Masoud; Tempel, Wolfram; Mackenzie, Farrell; Chau, Irene; Lourido, Sebastian; Sibley, L. David; Hui, Raymond (Toronto); (WU-MED)

    2010-09-21

    Calcium-dependent protein kinases (CDPKs) have pivotal roles in the calcium-signaling pathway in plants, ciliates and apicomplexan parasites and comprise a calmodulin-dependent kinase (CaMK)-like kinase domain regulated by a calcium-binding domain in the C terminus. To understand this intramolecular mechanism of activation, we solved the structures of the autoinhibited (apo) and activated (calcium-bound) conformations of CDPKs from the apicomplexan parasites Toxoplasma gondii and Cryptosporidium parvum. In the apo form, the C-terminal CDPK activation domain (CAD) resembles a calmodulin protein with an unexpected long helix in the N terminus that inhibits the kinase domain in the same manner as CaMKII. Calcium binding triggers the reorganization of the CAD into a highly intricate fold, leading to its relocation around the base of the kinase domain to a site remote from the substrate binding site. This large conformational change constitutes a distinct mechanism in calcium signal-transduction pathways.

  6. Live Imaging of Calcium Dynamics during Axon Degeneration Reveals Two Functionally Distinct Phases of Calcium Influx

    Science.gov (United States)

    Yamagishi, Yuya; Tessier-Lavigne, Marc

    2015-01-01

    Calcium is a key regulator of axon degeneration caused by trauma and disease, but its specific spatial and temporal dynamics in injured axons remain unclear. To clarify the function of calcium in axon degeneration, we observed calcium dynamics in single injured neurons in live zebrafish larvae and tested the temporal requirement for calcium in zebrafish neurons and cultured mouse DRG neurons. Using laser axotomy to induce Wallerian degeneration (WD) in zebrafish peripheral sensory axons, we monitored calcium dynamics from injury to fragmentation, revealing two stereotyped phases of axonal calcium influx. First, axotomy triggered a transient local calcium wave originating at the injury site. This initial calcium wave only disrupted mitochondria near the injury site and was not altered by expression of the protective WD slow (WldS) protein. Inducing multiple waves with additional axotomies did not change the kinetics of degeneration. In contrast, a second phase of calcium influx occurring minutes before fragmentation spread as a wave throughout the axon, entered mitochondria, and was abolished by WldS expression. In live zebrafish, chelating calcium after the first wave, but before the second wave, delayed the progress of fragmentation. In cultured DRG neurons, chelating calcium early in the process of WD did not alter degeneration, but chelating calcium late in WD delayed fragmentation. We propose that a terminal calcium wave is a key instructive component of the axon degeneration program. SIGNIFICANCE STATEMENT Axon degeneration resulting from trauma or neurodegenerative disease can cause devastating deficits in neural function. Understanding the molecular and cellular events that execute axon degeneration is essential for developing treatments to address these conditions. Calcium is known to contribute to axon degeneration, but its temporal requirements in this process have been unclear. Live calcium imaging in severed zebrafish neurons and temporally controlled

  7. Calcium isotope fractionation between soft and mineralized tissues as a monitor of calcium use in vertebrates

    Science.gov (United States)

    Skulan, Joseph; DePaolo, Donald J.

    1999-01-01

    Calcium from bone and shell is isotopically lighter than calcium of soft tissue from the same organism and isotopically lighter than source (dietary) calcium. When measured as the 44Ca/40Ca isotopic ratio, the total range of variation observed is 5.5‰, and as much as 4‰ variation is found in a single organism. The observed intraorganismal calcium isotopic variations and the isotopic differences between tissues and diet indicate that isotopic fractionation occurs mainly as a result of mineralization. Soft tissue calcium becomes heavier or lighter than source calcium during periods when there is net gain or loss of mineral mass, respectively. These results suggest that variations of natural calcium isotope ratios in tissues may be useful for assessing the calcium and mineral balance of organisms without introducing isotopic tracers. PMID:10570137

  8. Cardiovascular Effects of Calcium Supplements

    Directory of Open Access Journals (Sweden)

    Ian R. Reid

    2013-07-01

    Full Text Available Calcium supplements reduce bone turnover and slow the rate of bone loss. However, few studies have demonstrated reduced fracture incidence with calcium supplements, and meta-analyses show only a 10% decrease in fractures, which is of borderline statistical and clinical significance. Trials in normal older women and in patients with renal impairment suggest that calcium supplements increase the risk of cardiovascular disease. To further assess their safety, we recently conducted a meta-analysis of trials of calcium supplements, and found a 27%–31% increase in risk of myocardial infarction, and a 12%–20% increase in risk of stroke. These findings are robust because they are based on pre-specified analyses of randomized, placebo-controlled trials and are consistent across the trials. Co-administration of vitamin D with calcium does not lessen these adverse effects. The increased cardiovascular risk with calcium supplements is consistent with epidemiological data relating higher circulating calcium concentrations to cardiovascular disease in normal populations. There are several possible pathophysiological mechanisms for these effects, including effects on vascular calcification, vascular cells, blood coagulation and calcium-sensing receptors. Thus, the non-skeletal risks of calcium supplements appear to outweigh any skeletal benefits, and are they appear to be unnecessary for the efficacy of other osteoporosis treatments.

  9. Dietary Calcium Intake and Calcium Supplementation in Hungarian Patients with Osteoporosis

    Directory of Open Access Journals (Sweden)

    Gábor Speer

    2013-01-01

    Full Text Available Purpose. Adequate calcium intake is the basis of osteoporosis therapy—when this proves insufficient, even specific antiosteoporotic agents cannot exert their actions properly. Methods. Our representative survey analyzed the dietary intake and supplementation of calcium in 8033 Hungarian female and male (mean age: 68 years (68.01 (CI95: 67.81–68.21 patients with osteoporosis. Results. Mean intake from dietary sources was 665±7.9 mg (68.01 (CI95: 67.81–68.21 daily. A significant positive relationship could be detected between total dietary calcium intake and lumbar spine BMD (P=0.045, whereas such correlation could not be demonstrated with femoral T-score. Milk consumption positively correlated with femur (P=0.041, but not with lumbar BMD. The ingestion of one liter of milk daily increased the T-score by 0.133. Average intake from supplementation was 558±6.2 mg (68.01 (CI95: 67.81–68.21 daily. The cumulative dose of calcium—from both dietary intake and supplementation—was significantly associated with lumbar (r=0.024, P=0.049, but not with femur BMD (r=0.021, P=0.107. The currently recommended 1000–1500 mg total daily calcium intake was achieved in 34.5% of patients only. It was lower than recommended in 47.8% of the cases and substantially higher in 17.7% of subjects. Conclusions. We conclude that calcium intake in Hungarian osteoporotic patients is much lower than the current recommendation, while routinely applied calcium supplementation will result in inappropriately high calcium intake in numerous patients.

  10. Calcium oxalate stone and gout.

    Science.gov (United States)

    Marickar, Y M Fazil

    2009-12-01

    Gout is well known to be produced by increased uric acid level in blood. The objective of this paper is to assess the relationship between gout and calcium oxalate stone formation in the humans. 48 patients with combination of gout and calcium oxalate stone problem were included. The biochemical values of this group were compared with 38 randomly selected uric acid stone patients with gout, 43 stone patients with gout alone, 100 calcium oxalate stone patients without gout and 30 controls, making a total of 259 patients. Various biochemical parameters, namely serum calcium, phosphorus and uric acid and 24-h urine calcium, phosphorus, uric acid, oxalate, citrate and magnesium were analysed. ANOVA and Duncan's multiple-range tests were performed to assess statistical significance of the variations. The promoters of stone formation, namely serum calcium (P stone patients and gouty calcium oxalate stone patients compared to the non-gouty patients and controls. Urine oxalate (P stones patients. The inhibitor urine citrate (P stone gouty patients, followed by the gouty uric acid stone formers and gouty calcium oxalate stone patients. The high values of promoters, namely uric acid and calcium in the gouty stone patients indicate the tendency for urinary stone formation in the gouty stone patients. There is probably a correlation between gout and calcium oxalate urinary stone. We presume this mechanism is achieved through the uric acid metabolism. The findings point to the summation effect of metabolic changes in development of stone disease.

  11. Purification and reconstitution of the calcium antagonist receptor of the voltage-sensitive calcium channel

    International Nuclear Information System (INIS)

    Curtis, B.M.

    1986-01-01

    Treatment with digitonin solubilized the calcium antagonist receptor as a stable complex with [ 3 H]nitrendipine from rat brain membranes. The solubilized complex retains allosteric coupling to binding sites for diltiazem, verapamil, and inorganic calcium antagonist sites. The calcium antagonist receptor from cardiac sarcolemma and the transverse-tubule membrane of skeletal muscle is also efficiently solubilized with digitonin and the receptor in all three tissues is a large glycoprotein with a sedimentation coefficient of 20 S. The T-tubule calcium antagonist receptor complex was extensively purified by a combination of chromatography on WGA-Sepharose, ion exchange chromatography, and sedimentation on sucrose gradients to yield preparations estimated to be 41% homogeneous by specific activity and 63% homogeneous by SDS gel electrophoresis. Analysis of SDS gels detect three polypeptides termed α(Mr 135,000), β(Mr 50,000), and γ(Mr 32,000) as noncovalently associated subunits of the calcium antagonist receptor. The α and γ subunits are glycosylated polypeptides, and the molecular weight of the core polypeptides are 108,000 and 24,000 respectively. The calcium antagonist receptor was reconstituted into a phospholipid bilayer by adding CHAPS and exogeneous lipid to the purified receptor followed by rapid detergent removal. This procedure resulted in the incorporation of 45% of the calcium antagonist receptor into closed phospholipid vesicles. Data suggests that the α, β, and γ subunits of the T-tubule calcium antagonist receptor are sufficient to form a functional calcium channel

  12. Self-consistent, relativistic, ferromagnetic band structure of gadolinium

    International Nuclear Information System (INIS)

    Harmon, B.N.; Schirber, J.; Koelling, D.D.

    1977-01-01

    An initial self-consistent calculation of the ground state magnetic band structure of gadolinium is described. A linearized APW method was used which included all single particle relativistic effects except spin-orbit coupling. The spin polarized potential was obtained in the muffin-tin form using the local spin density approximation for exchange and correlation. The most striking and unorthodox aspect of the results is the position of the 4f spin-down ''bands'' which are required to float just on top of the Fermi level in order to obtain convergence. If the 4f states (l = 3 resonance) are removed from the occupied region of the conduction bands the magnetic moment is approximately .75 μ/sub B//atom; however, as the 4f spin-down states are allowed to find their own position they hybridize with the conduction bands at the Fermi level and the moment becomes smaller. Means of improving the calculation are discussed

  13. Nephrogenic systemic fibrosis after application of gadolinium-based contrast agents - a status paper; Nephrogene systemische Fibrose nach Anwendung gadoliniumhaltiger Kontrastmittel - ein Statuspapier zum aktuellen Stand des Wissens

    Energy Technology Data Exchange (ETDEWEB)

    Heinrich, M.; Uder, M. [Erlangen-Nuernberg Univ., Erlangen (Germany). Inst. fuer Radiologie

    2007-06-15

    Recently the association of a rare disease named ''nephrogenic systemic fibrosis'' (NSF) with the administration of gadolinium-containing contrast media, especially gadodiamide (Omniscan, GE-Healthcare), was described. NSF is a scleroderma-like disease characterised by widespread tissue fibrosis. Until now, NSF cases were observed only in patients with kidney disease. Almost all patients were suffering from chronic renal insufficiency, 90 % of them required renal replacement therapy. The true incidence of the disease is unknown. First retrospective analyses of selected collectives of patients with end-stage renal disease showed 2 - 5 % cases of NSF after administration of Gadolinium-containing contrast agents with an odds ratio of 20 - 50 in comparison to non-exposed controls. NSF is a serious adverse reaction, which may result in severe disabilities and even death. Therefore all radiologists applying gadolinium-based contrast agents should be informed about this disease and the recent recommendations for its prevention. On the basis of the published data, Omniscan should not be used in patients with severe renal impairment (GFR < 30 ml/min/1.73 m{sup 2}) and those who have had or are undergoing liver transplantation. In neonates and infants up to 1 year of age, Omniscan should only be used after careful consideration. Also the other gadolinium-based contrast agents should be used in high-risk patients only after careful consideration using the lowest dose possible.

  14. Gadolinium Enhanced MR Coronary Vessel Wall Imaging at 3.0 Tesla

    Directory of Open Access Journals (Sweden)

    Sebastian Kelle

    2010-01-01

    Full Text Available Purpose. We evaluated the influence of the time between low-dose gadolinium (Gd contrast administration and coronary vessel wall enhancement (LGE detected by 3T magnetic resonance imaging (MRI in healthy subjects and patients with coronary artery disease (CAD. Materials and Methods. Four healthy subjects (4 men, mean age 29  ±  3 years and eleven CAD patients (6 women, mean age 61±10 years were studied on a commercial 3.0 Tesla (T whole-body MR imaging system (Achieva 3.0 T; Philips, Best, The Netherlands. T1-weighted inversion-recovery coronary magnetic resonance imaging (MRI was repeated up to 75 minutes after administration of low-dose Gadolinium (Gd (0.1 mmol/kg Gd-DTPA. Results. LGE was seen in none of the healthy subjects, however in all of the CAD patients. In CAD patients, fifty-six of 62 (90.3% segments showed LGE of the coronary artery vessel wall at time-interval 1 after contrast. At time-interval 2, 34 of 42 (81.0% and at time-interval 3, 29 of 39 evaluable segments (74.4% were enhanced. Conclusion. In this work, we demonstrate LGE of the coronary artery vessel wall using 3.0 T MRI after a single, low-dose Gd contrast injection in CAD patients but not in healthy subjects. In the majority of the evaluated coronary segments in CAD patients, LGE of the coronary vessel wall was already detectable 30–45 minutes after administration of the contrast agent.

  15. Self-assembled gemcitabine-gadolinium nanoparticles for magnetic resonance imaging and cancer therapy.

    Science.gov (United States)

    Li, Lele; Tong, Rong; Li, Mengyuan; Kohane, Daniel S

    2016-03-01

    Nanoparticles with combined diagnostic and therapeutic functions are promising tools for cancer diagnosis and treatment. Here, we demonstrate a theranostic nanoparticle that integrates an active gemcitabine metabolite and a gadolinium-based magnetic resonance imaging agent via a facile supramolecular self-assembly synthesis, where the anti-cancer drug gemcitabine-5'-monophosphate (a phosphorylated active metabolite of the anti-cancer drug gemcitabine) was used to coordinate with Gd(III) to self-assemble into theranostic nanoparticles. The formulation exhibits a strong T1 contrast signal for magnetic resonance imaging of tumors in vivo, with enhanced retention time. Furthermore, the nanoparticles did not require other inert nanocarriers or excipients and thus had an exceptionally high drug loading (55 wt%), resulting in the inhibition of MDA-MB-231 tumor growth in mice. Recent advances in nanoparticle-based drug delivery systems have spurred the development of "theranostic" multifunctional nanoparticles, which combine therapeutic and diagnostic functionalities in a single formulation. Developing simple and efficient synthetic strategies for the construction of nanotheranostics with high drug loading remains a challenge. Here, we demonstrate a theranostic nanoparticle that integrates high loadings of an active gemcitabine metabolite and a gadolinium-based magnetic resonance imaging agent via a facile synthesis. The nanoparticles were better T1 contrast agents than currently used Gd-DTPA and had prolonged retention in tumor. Moreover they exhibited enhanced in vivo antitumor activity compared to free drug in a breast cancer xenograft mouse model. The strategy provides a scalable way to fabricate nanoparticles that enables enhancement of both therapeutic and diagnostic capabilities. Published by Elsevier Ltd.

  16. Why Calcium? How Calcium Became the Best Communicator*

    OpenAIRE

    Carafoli, Ernesto; Krebs, Joachim

    2016-01-01

    Calcium carries messages to virtually all important functions of cells. Although it was already active in unicellular organisms, its role became universally important after the transition to multicellular life. In this Minireview, we explore how calcium ended up in this privileged position. Most likely its unique coordination chemistry was a decisive factor as it makes its binding by complex molecules particularly easy even in the presence of large excesses of other cations,...

  17. Calcium-Induced calcium release during action potential firing in developing inner hair cells.

    Science.gov (United States)

    Iosub, Radu; Avitabile, Daniele; Grant, Lisa; Tsaneva-Atanasova, Krasimira; Kennedy, Helen J

    2015-03-10

    In the mature auditory system, inner hair cells (IHCs) convert sound-induced vibrations into electrical signals that are relayed to the central nervous system via auditory afferents. Before the cochlea can respond to normal sound levels, developing IHCs fire calcium-based action potentials that disappear close to the onset of hearing. Action potential firing triggers transmitter release from the immature IHC that in turn generates experience-independent firing in auditory neurons. These early signaling events are thought to be essential for the organization and development of the auditory system and hair cells. A critical component of the action potential is the rise in intracellular calcium that activates both small conductance potassium channels essential during membrane repolarization, and triggers transmitter release from the cell. Whether this calcium signal is generated by calcium influx or requires calcium-induced calcium release (CICR) is not yet known. IHCs can generate CICR, but to date its physiological role has remained unclear. Here, we used high and low concentrations of ryanodine to block or enhance CICR to determine whether calcium release from intracellular stores affected action potential waveform, interspike interval, or changes in membrane capacitance during development of mouse IHCs. Blocking CICR resulted in mixed action potential waveforms with both brief and prolonged oscillations in membrane potential and intracellular calcium. This mixed behavior is captured well by our mathematical model of IHC electrical activity. We perform two-parameter bifurcation analysis of the model that predicts the dependence of IHCs firing patterns on the level of activation of two parameters, the SK2 channels activation and CICR rate. Our data show that CICR forms an important component of the calcium signal that shapes action potentials and regulates firing patterns, but is not involved directly in triggering exocytosis. These data provide important insights

  18. 21 CFR 573.260 - Calcium silicate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Calcium silicate. 573.260 Section 573.260 Food and... Listing § 573.260 Calcium silicate. Calcium silicate, including synthetic calcium silicate, may be safely used as an anticaking agent in animal feed, provided that the amount of calcium silicate does not...

  19. 21 CFR 573.240 - Calcium periodate.

    Science.gov (United States)

    2010-04-01

    ... with calcium hydroxide or calcium oxide to form a substance consisting of not less than 60 percent by... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Calcium periodate. 573.240 Section 573.240 Food... Additive Listing § 573.240 Calcium periodate. The food additive calcium periodate may be safely used in...

  20. The complex fate in plasma of gadolinium incorporated into high-density lipoproteins used for magnetic imaging of atherosclerotic plaques

    NARCIS (Netherlands)

    Barazza, Alessandra; Blachford, Courtney; Even-Or, Orli; Joaquin, Victor A.; Briley-Saebo, Karen C.; Chen, Wei; Jiang, Xian-Cheng; Mulder, Willem J. M.; Cormode, David P.; Fayad, Zahi A.; Fisher, Edward A.

    2013-01-01

    We have previously reported enhancing the imaging of atherosclerotic plaques in mice using reconstituted high density lipoproteins (HDL) as nanocarriers for the MRI contrast agent gadolinium (Gd). This study focuses on the underlying mechanisms of Gd delivery to atherosclerotic plaques. HDL, LDL,

  1. Modeling systemic and renal gadolinium chelate transport with MRI

    Energy Technology Data Exchange (ETDEWEB)

    Votaw, John R.; Martin, Diego [Emory University Hospital, Department of Radiology, Atlanta, GA (United States)

    2008-01-15

    The advent of modern MRI scanners and computer equipment permits the rapid sequential collection of images of gadolinium chelate (Gd) transit through the kidney. The excellent spatial and temporal (0.9 s) resolution permits analyzing the shape of the recovered curves with a sophisticated model that includes both space and time. The purpose of this manuscript is to present such a mathematical model. By building into the model significant physical processes that contribute to the shape of the measured curve, quantitative values can be assigned to important parameters. In this work, quantitative values are determined for blood dispersion through the cardio-pulmonary system, systemic clearance rate of Gd, blood flow into each kidney, blood transit time in each kidney, the extraction rate of Gd across the capillary membrane, interstitial distribution volume, and the GFR for each kidney. (orig.)

  2. Role of gadolinium in MR imaging of sinonasal masses

    International Nuclear Information System (INIS)

    Lanzieri, C.F.; Shah, M.; Smith, A.S.; Tarr, R.; Van Dyke, C.; Kaufman, B.; Krauss, D.; Lavertu, P.

    1990-01-01

    This paper determines whether additional clinically useful information can be obtained with the use of contrast-enhanced MR imaging, compared with nonenhanced MR imaging and enhanced CT, in the evaluation of patients with sinonasal masses. Twenty-one patients with CT evidence of a sinonasal mass were imaged at 1.5 T with T1 and T2 weighting and without and with gadolinium injection. The studies were interpreted independently and correlated with the surgical and pathologic findings. The contrast-enhanced MR images yielded additional clinically useful information in 13 of 21 cases. It was the only way to separate tumor from a mucocele in four of 13 cases. In two of 13 instances, it was the only modality that identified encephalocele as distinct from a tumor. In the remaining seven cases, more accurate delineation of the tumor margins was obtained

  3. Calcium chromate process related investigations

    International Nuclear Information System (INIS)

    Dillard, B.M.

    1979-01-01

    A pilot plant for production of calcium chromate has been scaled up to a small production facility at the General Electric Neutron Devices Department. In preparation for this scale-up, the process and final product were studied in order to evaluate problems not considered previously. The variables and processes studied included: (1) the determination of optimum drying temperature and time for product analysis; (2) the effect of the grade of lime used as the precipitating agent on the purity of the calcium chromate; (3) product purity when calcium chromate is precipitated by the addition of ammonium chromate to slaked lime; (4) the reagents best suited for cleaning calcium chromate spills; and (5) methods for determining hydroxide ion concentration in calcium chromate. The optimum drying time for the product before analysis is four hours at 600 0 C. Gases evolved at various temperatures during the drying process were carbon dioxide and water vapor. Technical grade lime produced calcium chromate of the highest purity. Both nitric and acetic acids were efficient dissolvers of calcium chromate spills. Direct titration of hydroxide ion with sulfuric acid gave an average recovery of 93% for samples spiked with calcium hydroxide. 1 figure, 17 tables

  4. [The fasting calcium/creatinine ratio in patients with calcium stones and the relation with hypercalciuria and phosphocalcium metabolism].

    Science.gov (United States)

    Arrabal-Polo, Miguel Ángel; del Carmen Cano-García, María; Arrabal-Martín, Miguel

    2016-04-01

    To determine the importance of fasting calcium/creatinine ratio in patients with calcium stones and its relation with hypercalciuria and phospho-calcium metabolism. Cross-sectional study including 143 patients divided into two groups according to fasting calcium/creatinine. Group 1: 66 patients (calcium/ creatininecreatinine>0.11). A comparative study is performed between groups including phospho-calcium metabolism parameters and excretion of urinary lithogenic markers. Linear correlation studying calciuria and fasting calcium/ creatinine was performed. SPSS 17.0 statistical analysis software was used, considering p≤0.05. It is noteworthy that group 2 had increased 24 h urine calcium excretion in comparison to group 1 (229.3 vs 158.1; p=0.0001) and calcium/citrate (0.47 vs 0.34; p=0.001). There is a positive and significant correlation between calcium levels in 24 h urine and fasting calcium/creatinine (R=0.455; p=0.0001) and a cutoff is set at 0.127 (sensitivity 72%, specificity 66%) to determine hypercalciuria (>260 mg in 24 h). Increased fasting calcium/creatinine determines increased 24 hours calcium excretion, although the sensitivity and specificity to determine hypercalciuria is not high.

  5. Left Ventricular Function Evaluation on a 3T MR Scanner with Parallel RF Transmission Technique: Prospective Comparison of Cine Sequences Acquired before and after Gadolinium Injection.

    Science.gov (United States)

    Caspar, Thibault; Schultz, Anthony; Schaeffer, Mickaël; Labani, Aïssam; Jeung, Mi-Young; Jurgens, Paul Thomas; El Ghannudi, Soraya; Roy, Catherine; Ohana, Mickaël

    To compare cine MR b-TFE sequences acquired before and after gadolinium injection, on a 3T scanner with a parallel RF transmission technique in order to potentially improve scanning time efficiency when evaluating LV function. 25 consecutive patients scheduled for a cardiac MRI were prospectively included and had their b-TFE cine sequences acquired before and right after gadobutrol injection. Images were assessed qualitatively (overall image quality, LV edge sharpness, artifacts and LV wall motion) and quantitatively with measurement of LVEF, LV mass, and telediastolic volume and contrast-to-noise ratio (CNR) between the myocardium and the cardiac chamber. Statistical analysis was conducted using a Bayesian paradigm. No difference was found before or after injection for the LVEF, LV mass and telediastolic volume evaluations. Overall image quality and CNR were significantly lower after injection (estimated coefficient cine after > cine before gadolinium: -1.75 CI = [-3.78;-0.0305], prob(coef>0) = 0% and -0.23 CI = [-0.49;0.04], prob(coef>0) = 4%) respectively), but this decrease did not affect the visual assessment of LV wall motion (cine after > cine before gadolinium: -1.46 CI = [-4.72;1.13], prob(coef>0) = 15%). In 3T cardiac MRI acquired with parallel RF transmission technique, qualitative and quantitative assessment of LV function can reliably be performed with cine sequences acquired after gadolinium injection, despite a significant decrease in the CNR and the overall image quality.

  6. Calcium regulation and Alzheimer’s disease

    Directory of Open Access Journals (Sweden)

    Deepthi Rapaka

    2014-09-01

    Full Text Available Activation of the neuron induces transient fluctuations in [Ca2+]i. This transient rise in [Ca2+]i is dependent on calcium entry via calcium channels and release of calcium from intracellular stores, finally resulting in increase in calcium levels, which activates calcium regulatory proteins to restore the resting calcium levels by binding to the calcium-binding proteins, sequestration into the endoplasmic reticulum and the mitochondria, and finally extrusion of calcium spike potential from the cell by adenosine triphosphate-driven Ca2+ pumps and the Na+/Ca2+ exchanger. Improper regulation of calcium signaling, sequentially, likely contributes to synaptic dysfunction and excitotoxic and/or apoptotic death of the vulnerable neuronal populations. The cognitive decline associated with normal aging is not only due to neuronal loss, but is fairly the result of synaptic connectivity. Many evidences support that Ca2+ dyshomeostasis is implicated in normal brain aging. Thus the chief factor associated with Alzheimer’s disease was found to be increase in the levels of free intracellular calcium, demonstrating that the excessive levels might lead to cell death, which provides a key target for the calcium channel blockers might be used as the neuroprotective agents in Alzheimer’s disease.

  7. 21 CFR 184.1207 - Calcium lactate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Calcium lactate. 184.1207 Section 184.1207 Food and... Substances Affirmed as GRAS § 184.1207 Calcium lactate. (a) Calcium lactate (C6H10CaO6.xH2O, where x is any... calcium carbonate or calcium hydroxide. (b) The ingredient meets the specifications of the Food Chemicals...

  8. Structural, kinetic, and thermodynamic characterization of the interconverting isomers of MS-325, a gadolinium(III)-based magnetic resonance angiography contrast agent.

    Science.gov (United States)

    Tyeklar, Zoltan; Dunham, Stephen U; Midelfort, Katarina; Scott, Daniel M; Sajiki, Hirano; Ong, Karen; Lauffer, Randall B; Caravan, Peter; McMurry, Thomas J

    2007-08-06

    The amphiphilic gadolinium complex MS-325 ((trisodium-{(2-(R)-[(4,4-diphenylcyclohexyl) phosphonooxymethyl] diethylenetriaminepentaacetato) (aquo)gadolinium(III)}) is a contrast agent for magnetic resonance angiography (MRA). MS-325 comprises a GdDTPA core with an appended phosphodiester moiety linked to a diphenylcyclohexyl group to facilitate noncovalent binding to serum albumin and extension of the plasma half-life in vivo. The chiral DTPA ligand (R) was derived from L-serine, and upon complexation with gadolinium, forms two interconvertible diastereomers, denoted herein as isomers A and B. X-ray crystallography of the tris(ethylenediamine)cobalt(III) salt derivative of isomer A revealed a structure in the polar acentric space group P32. The structure consisted of three independent molecules of the gadolinium complex in the asymmetric unit along with three Delta-[Co(en)3]3+ cations, and it represents an unusual example of spontaneous Pasteur resolution of the cobalt cation. The geometry of the coordination core was best described as a distorted trigonal prism, and the final R factor was 5.6%. The configuration of the chiral central nitrogen of the DTPA core was S. The Gd-water (2.47-2.48 A), the Gd-acetate oxygens (2.34-2.42 A), and the Gd-N bond distances (central N, 2.59-2.63 A; terminal N, 2.74-2.80 A) were similar to other reported GdDTPA structures. The structurally characterized single crystal was one of two interconvertable diastereomers (isomers A and B) that equilibrated to a ratio of 1.81 to 1 at pH 7.4 and were separable at elevated pH by ion-exchange chromatography. The rate of isomerization was highly pH dependent: k1 = (1.45 +/- 0.08) x 102[H+] + (4.16 +/- 0.30) x 105[H+]2; k-1 = (2.57 +/- 0.17) x 102[H+] + (7.54 +/- 0.60) x 105[H+]2.

  9. Calcium Occupancy of N-terminal Sites within Calmodulin Induces Inhibition of the Ryanodine Receptor Calcium Release Channel

    Energy Technology Data Exchange (ETDEWEB)

    Boschek, Curt B; Jones, Terry E; Squier, Thomas C; Bigelow, Diana J

    2007-08-01

    Calmodulin (CaM) regulates calcium release from intracellular stores in skeletal muscle through its association with the ryanodine receptor (RyR1) calcium release channel, where CaM association enhances channel opening at resting calcium levels and its closing at micromolar calcium levels associated with muscle contraction. A high-affinity CaM-binding sequence (RyRp) has been identified in RyR1, which corresponds to a 30-residue sequence (i.e., K3614 – N3643) located within the central portion of the primary sequence. However, it is currently unclear whether the identified CaM-binding sequence a) senses calcium over the physiological range of calcium-concentrations associated with RyR1 regulation or b) plays a structural role unrelated to the calcium-dependent modulation of RyR1 function. Therefore, we have measured the calcium-dependent activation of the individual domains of CaM in association with RyRp and their relationship to the CaM-dependent regulation of RyR1. These measurements utilize an engineered CaM, permitting the site-specific incorporation of N-(1-pyrene) maleimide at either T34C (PyN-CaM) or T110C (PyC-CaM) in the N- and C-domains, respectively. Consistent with prior measurements, we observe a high-affinity association between both apo- and calcium-activated CaM and RyRp. Upon association with RyRp, fluorescence changes in PyN-CaM or PyC-CaM permit the measurement of the calcium-activation of these individual domains. Fluorescence changes upon calcium-activation of PyC-CaM in association with RyRp are indicative of high-affinity calcium-dependent activation of the C-terminal domain of CaM bound to RyRp at resting calcium levels and the activation of the N-terminal domain at levels of calcium associated cellular activation. In comparison, occupancy of calcium-binding sites in the N-domain of CaM mirrors the calcium-dependence of RyR1 inhibition observed at activating calcium levels, where [Ca]1/2 = 4.3 0.4 μM, suggesting a direct regulation of Ry

  10. Penetration and distribution of gadolinium-based contrast agents into the cerebrospinal fluid in healthy rats: a potential pathway of entry into the brain tissue

    Energy Technology Data Exchange (ETDEWEB)

    Jost, Gregor; Frenzel, Thomas; Lohrke, Jessica; Pietsch, Hubertus [MR and CT Contrast Media Research, Bayer Pharma AG, Berlin (Germany); Lenhard, Diana Constanze [Charite, Institute of Vegetative Physiology, Berlin (Germany); Naganawa, Shinji [Nagoya University Graduate School of Medicine, Department of Radiology, Nagoya (Japan)

    2017-07-15

    Signal hyperintensity on unenhanced MRI in certain brain regions has been reported after multiple administrations of some, but not all, gadolinium-based contrast agents (GBCAs). One potential initial pathway of GBCA entry into the brain, infiltration from blood into the cerebrospinal fluid (CSF), was systematically evaluated in this preclinical study. GBCA infiltration and distribution in the CSF were investigated in healthy rats using repeated fluid-attenuated MRI up to 4 h after high-dose (1.8 mmol/kg) administration of six marketed and one experimental GBCA. Additionally, gadolinium measurements in CSF, blood and brain tissue samples (after 24 h) were performed using inductively coupled plasma mass spectrometry. Enhanced MRI signals in the CSF spaces with similar distribution kinetics were observed for all GBCAs. No substantial differences in the gadolinium concentrations among the marketed GBCAs were found in the CSF, blood or brain tissue. After 4.5 h, the concentration in the CSF was clearly higher than in blood but was almost completely cleared and lower than the brain tissue concentration after 24 h. In contrast to the brain signal hyperintensities, no differences in penetration and distribution into the CSF of healthy rats exist among the marketed GBCAs. (orig.)

  11. Penetration and distribution of gadolinium-based contrast agents into the cerebrospinal fluid in healthy rats: a potential pathway of entry into the brain tissue

    International Nuclear Information System (INIS)

    Jost, Gregor; Frenzel, Thomas; Lohrke, Jessica; Pietsch, Hubertus; Lenhard, Diana Constanze; Naganawa, Shinji

    2017-01-01

    Signal hyperintensity on unenhanced MRI in certain brain regions has been reported after multiple administrations of some, but not all, gadolinium-based contrast agents (GBCAs). One potential initial pathway of GBCA entry into the brain, infiltration from blood into the cerebrospinal fluid (CSF), was systematically evaluated in this preclinical study. GBCA infiltration and distribution in the CSF were investigated in healthy rats using repeated fluid-attenuated MRI up to 4 h after high-dose (1.8 mmol/kg) administration of six marketed and one experimental GBCA. Additionally, gadolinium measurements in CSF, blood and brain tissue samples (after 24 h) were performed using inductively coupled plasma mass spectrometry. Enhanced MRI signals in the CSF spaces with similar distribution kinetics were observed for all GBCAs. No substantial differences in the gadolinium concentrations among the marketed GBCAs were found in the CSF, blood or brain tissue. After 4.5 h, the concentration in the CSF was clearly higher than in blood but was almost completely cleared and lower than the brain tissue concentration after 24 h. In contrast to the brain signal hyperintensities, no differences in penetration and distribution into the CSF of healthy rats exist among the marketed GBCAs. (orig.)

  12. MR imaging of the knee joint plain, after intraarticular administration of gadolinium DTPA, common salt and air

    International Nuclear Information System (INIS)

    Baum, H.; Kuehnert, A.; Sundermeyer, R.

    1987-01-01

    Noninvasive MRI of the knee joint yields a great deal of information on soft parts (ligaments, capsule, free fluid, menisci, cartilage) and bones. The image is changed by intraarticular administration of air and of small quantities of fluids that supply many signals, such as gadolinium DTPA solution. The results and possibilities of application are discussed. (orig.) [de

  13. Gadolinium for neutron detection in current nuclear instrumentation research: A review

    Science.gov (United States)

    Dumazert, J.; Coulon, R.; Lecomte, Q.; Bertrand, G. H. V.; Hamel, M.

    2018-02-01

    Natural gadolinium displays a number of remarkable physical properties: it is a rare earth element, composed of seven stable or quasi-stable isotopes, with an exceptionally high magnetization and a Curie point near room temperature. Its use in the field of nuclear instrumentation historically relates to its efficiency as a neutron poison in power reactors. Gadolinium is indeed the naturally occurring element with the highest interaction probability with neutrons at thermal energy, shared between Gd-157 (15.65%, 254000 b cross section) and Gd-155 (14.8%, 60900 b) isotopes. Considering that neutron capture results in an isotopic change, followed by a radiative rearrangement of nuclear and atomic structures, Gd may be embodied not merely as a neutron poison but as a neutron converter into a prompt photon and an electron source term. Depending on the nature and energy of the reaction products (from a few-keV Auger electrons up to 8 MeV gamma rays) that the detector aims at isolating as an indirect neutron signature, a variety of sensor media and counting methods have been introduced during the last decades. This review first draws a theoretical description of the radiative cascade following Gd(n , γ) capture. The cascade may be subdivided into regions of interest, each corresponding to dedicated detection designs and optimizations whose current status is detailed. This inventory has allowed the authors to extract and benchmark key figures of merit for the definition of a detection scheme: neutron attenuation, neutron sensitivity (cps/nv), gamma rejection, neutron detection limit in a mixed field, intrinsic or extrinsic moderation, and transportability. On this basis, the authors have identified promising paths for Gd-based neutron detection in contemporary instrumentation.

  14. Acidosis and Urinary Calcium Excretion

    DEFF Research Database (Denmark)

    Alexander, R Todd; Cordat, Emmanuelle; Chambrey, Régine

    2016-01-01

    Metabolic acidosis is associated with increased urinary calcium excretion and related sequelae, including nephrocalcinosis and nephrolithiasis. The increased urinary calcium excretion induced by metabolic acidosis predominantly results from increased mobilization of calcium out of bone and inhibi...

  15. Calcium microdomains near R-type calcium channels control the induction of presynaptic LTP at parallel fiber to Purkinje cell synapses

    Science.gov (United States)

    Myoga, Michael H.; Regehr, Wade G.

    2011-01-01

    R-type calcium channels in postsynaptic spines signal through functional calcium microdomains to regulate a calcium-calmodulin sensitive potassium channel that in turn regulates postsynaptic hippocampal LTP. Here we ask whether R-type calcium channels in presynaptic terminals also signal through calcium microdomains to control presynaptic LTP. We focus on presynaptic LTP at parallel fiber to Purkinje cell synapses in the cerebellum (PF-LTP), which is mediated by calcium/calmodulin-stimulated adenylyl cyclases. Although most presynaptic calcium influx is through N-type and P/Q-type calcium channels, blocking these channels does not disrupt PF-LTP, but blocking R-type calcium channels does. Moreover, global calcium signaling cannot account for the calcium dependence of PF-LTP because R-type channels contribute modestly to overall calcium entry. These findings indicate that within presynaptic terminals, R-type calcium channels produce calcium microdomains that evoke presynaptic LTP at moderate frequencies that do not greatly increase global calcium levels,. PMID:21471358

  16. Liver nodules. MR imaging using extracellular gadolinium agent

    International Nuclear Information System (INIS)

    Yoshimitsu, Kengo; Honda, Hiroshi

    2009-01-01

    Extracellular gadolinium (Gd)-containing contrast medium, including gadopentetate dimeglumine (Gd-DTPA), has been playing a main role in the diagnostic MR imaging of the liver. Its significance is two-fold: assessment of the degree of neovascularity or angiogenesis in its early dynamic phase, and that of bulk of interstitium in its equilibrium phase. With the advent of gadolinium ethoxybenzyl diethylenetriamine-pentaacetic acid (Gd-EOB-DTPA), which can be used as a dynamic study agent by bolus injection in addition to its original use as a tissue-specific agent, some possibility has been suggested that extracellular Gd agent would be no longer available in the near future in the field of liver MR imaging. Neovascularity or arterial supply of a lesion may well be assessed by Gd-EOB-DTPA, when carefully selected pulse sequence and well designed injection protocol are used, as well as by Gd-DTPA. However, the pertinent assessment of interstitium or stroma can never be achieved by Gd-EOB-DTPA or any other contrast medium present. The interstitium of neoplasm, typically called as stromal fibrosis, is generated through the interaction between the neoplasm per se and its host, and its clinicopathological significance related to disease prognosis has well been established in some disease entities. Extracellular Gd agent is the only contrast medium that can provide information regarding the tumor stroma in a simple, easy, safe and non-invasive fashion, when properly used. This review article discusses, dynamic MR imaging features of representative liver diseases, including several recent topics. From technical point of view, 3D gradient-echo sequence with fat suppression should be used for dynamic studies along with tailored injection protocol using autoinjector and saline flush. Vascularity of hepatocellular carcinoma (HCC) can now be properly assessed by dynamic MR with approximately 90% concordance with CT during hepatic arteriography. Portal phase images can be used to

  17. The role of calcium utilization of intestinal flora on urinary calcium excretion

    International Nuclear Information System (INIS)

    Yurt Lambrecht, F.; Uenak, P.; Kavukcu, S.; Soylu, A.; Tuerkmen, M.; Kasap, B.; Yucesoy, M.; Esen, N.

    2005-01-01

    Aim: To investigate whether calcium utilization of intestinal flora has any effect on urinary calcium excretion, like oxalate degrading effect of Oxalobacter formigenes. Materials and Methods: The data of urinary calcium excretion examinations were evaluated. 0.1 g/ml of feces samples were implanted in broths. 5 μL of 45 Ca solution was added to the samples and they were incubated for 24 hours at 37 degree C. The amount of bacteriae in the samples was determined as colony forming unit (CFU). 200 μL of the samples were filtrated by 0.45 μm membrane and rinsed by 200 μL pure water. 45 Ca activity ( 45 Ca) of bacteria in the membrane was counted by GM detector for 100 seconds. Then, activity per CFU ( 45 Ca/CFU) was calculated and compared in hypercalciuric (calciuria >4; mg/kg/hour and/or calcium/creatinine ratio>0.21; Group I) and normocalciuric (Group II) patients. Results: Samples of 29 patients with a mean age of 7.50±4.28 (1.5-16) years were evaluated. 11 of them were female (M/F: 18/11). There were 14 patients in Group I and 15 patients in Group II, 45 Ca/CFU was not different for neither aerobic nor anaerobic bacteries between the two groups (p:0.983, p:0.601, respectively). 24-hour urine calcium levels were negatively but not significantly correlated to aerobic and anaerobic 45 Ca/CFU (p:0.079, r:-0.145; p:0.260, r:-0.420, respectively) in hypercalciuric patients. Besides, in normocalciuric patients, 24-hour urine calcium levels were correlated positively to aerobic and negatively to anaerobic 45 Ca/CFU again in an insignificant manner (p:0.509, r: 0.223; p:0623, r:-0.257, respectively). Conclusion: In this, study, similar 45 Ca/CFU levels in both hypercalciuric and normocalciuric patients imply that calcium utilization of intestinal flora does not have a distinct effect on urinary calcium excretion but, although not significant, there was a negative correlation between urine calcium levels and bacterial 45 Ca/CFU levels especially in hypercalciuric

  18. Movement of calcium signals and calcium-binding proteins: firewalls, traps and tunnels.

    Science.gov (United States)

    Barrow, S L; Sherwood, M W; Dolman, N J; Gerasimenko, O V; Voronina, S G; Tepikin, A V

    2006-06-01

    In the board game 'Snakes and Ladders', placed on the image of a pancreatic acinar cell, calcium ions have to move from release sites in the secretory region to the nucleus. There is another important contraflow - from calcium entry channels in the basal part of the cell to ER (endoplasmic reticulum) terminals in the secretory granule region. Both transport routes are perilous as the messenger can disappear in any place on the game board. It can be grabbed by calcium ATPases of the ER (masquerading as a snake but functioning like a ladder) and tunnelled through its low buffering environment, it can be lured into the whirlpools of mitochondria uniporters and forced to regulate the tricarboxylic acid cycle, and it can be permanently placed inside the matrix of secretory granules and released only outside the cell. The organelles could trade calcium (e.g. from the ER to mitochondria and vice versa) almost depriving this ion the light of the cytosol and noble company of cytosolic calcium buffers. Altogether it is a rich and colourful story.

  19. The use of innovative gadolinium-based contrast agent for MR-diagnosis of cancer in the experiment

    International Nuclear Information System (INIS)

    Chernov, V; Medvedeva, A; Sinilkin, I; Zelchan, R; Grigorev, E; Frolova, I; Nam, I

    2016-01-01

    The present study of the functional suitability and specific activity of the contrast agent gadolinium-based for magnetic resonance imaging demonstrated that the investigated contrast agent intensively accumulates in organs and anatomical structures of the experimental animals. In the model of tumor lesions in animals, study have shown that investigational contrast agent accumulates in the tumor tissue and retained there in for a long enough time. (paper)

  20. Can aquatic macrophytes be biofilters for gadolinium based contrasting agents?

    Science.gov (United States)

    Braun, Mihály; Zavanyi, Györgyi; Laczovics, Attila; Berényi, Ervin; Szabó, Sándor

    2018-05-15

    The use of gadolinium-based contrasting agents (GBCA) is increasing because of the intensive usage of these agents in magnetic resonance imaging (MRI). Waste-water treatment does not reduce anthropogenic Gd-concentration significantly. Anomalous Gd-concentration in surface waters have been reported worldwide. However, removal of GBCA-s by aquatic macrophytes has still hardly been investigated. Four aquatic plant species (Lemna gibba, Ceratophyllum demersum, Elodea nuttallii, E. canadensis) were investigated as potential biological filters for removal of commonly used but structurally different GBCA-s (Omniscan, Dotarem) from water. These plant species are known to accumulate heavy metals and are used for removing pollutants in constructed wetlands. The Gd uptake and release of the plants was examined under laboratory conditions. Concentration-dependent infiltration of Gd into the body of the macrophytes was measured, however significant bioaccumulation was not observed. The tissue concentration of Gd reached its maximum value between day one and four in L. gibba and C. demersum, respectively, and its volume was significantly higher in C. demersum than in L. gibba. In C. demersum, the open-chain ligand Omniscan causes two-times higher tissue Gd concentration than the macrocyclic ligand Dotarem. Gadolinium was released from Gd-treated duckweeds into the water as they were grown further in Gd-free nutrient solution. Tissue Gd concentration dropped by 50% in duckweed treated by Omniscan and by Dotarem within 1.9 and 2.9 days respectively. None of the macrophytes had a significant impact on the Gd concentration of water in low and medium concentration levels (1-256 μg L -1 ). Biofiltration of GBCA-s by common macrophytes could not be detected in our experiments. Therefore it seems that in constructed wetlands, aquatic plants are not able to reduce the concentration of GBCA-s in the water. Furthermore there is a low risk that these plants cause the