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Sample records for citrate buffer edta

  1. Ion exchange behaviour of citrate and EDTA anions on strong and weak base organic ion exchangers

    International Nuclear Information System (INIS)

    Askarieh, M.M.; White, D.A.

    1988-01-01

    The exchange of citrate and EDTA ions with two strong base and two weak base exchangers is considered. Citrate and EDTA analysis for this work was performed using a colorimetric method developed here. The ions most selectively exchanged on the resins are H 2 cit - and H 2 EDTA 2- , though EDTA is generally less strongly sorbed on strong base resins. In contact with weak base resins, deprotonation of the resin occurs during ion exchange with a noticeable drop in solution pH. Although EDTA sorption can be reversed by nitric acid, citrate ions are significantly held on the resin at low pH. The exchange of citrate can be made reversible if bicarbonate is added to the initial solutions. Alkaline regeneration of exchangers loaded with EDTA proved to be very effective. (author)

  2. Sodium citrate blood contamination by K2 -ethylenediaminetetraacetic acid (EDTA): impact on routine coagulation testing.

    Science.gov (United States)

    Lima-Oliveira, G; Salvagno, G L; Danese, E; Favaloro, E J; Guidi, G C; Lippi, G

    2015-06-01

    The potential cross-contamination of additives between primary blood tubes is a well-known problem during sample collection. The aim of this study was to assess the impact of citrated blood contamination with different amounts of dipotassium ethylenediaminetetraacetic (K2 EDTA blood) on activated partial thromboplastin time (APTT), prothrombin time (PT), and fibrinogen. Blood was collected from 15 ostensibly healthy volunteers into four 0.109 m citrate blood tubes followed by one K2 EDTA blood tube. The citrate tubes of each subject were pooled and divided in five aliquots. The whole blood of the K2 EDTA tube was then added in scalar amounts to autologous citrated blood aliquots, to obtain K2 EDTA contamination ranging from 0% to 43%, and thus mimic potential pre-analytical contamination. A statistically and clinically significant prolongation was observed for both APTT and PT between 29% and 43% K2 EDTA contamination, whereas the decrease of fibrinogen values became statistically and clinically significant at 43% K2 EDTA contamination. The results of this investigation show that contamination of citrated blood with as much as 29% of K2 EDTA blood generates a significant bias in results of routine clotting assays. This has serious implications for patient safety and management. © 2014 John Wiley & Sons Ltd.

  3. The influence of using anticoagulants (EDTA and citrate acid 3.8% toward the quantity of Platelet Rich Plasma (PRP

    Directory of Open Access Journals (Sweden)

    Lilies Anggarwati Astuti

    2016-06-01

    Full Text Available Platelet Rich Plasma (PRP is a blood concentrate that has a thrombocytes concentration several time higher than normal concentration of thrombocytes in normal human blood. PRP is a promising alternative to surgery with a safe and natural healing. The standard protocol for PRP preparation must be determined to get the right quantity and quality of the matrix of fibrin, leukocytes, platelets and growth factors. It could not be separated from the number of PRP produced. The use of PRP in the success of periodontal treatment would not be separated from methods to obtain it. To detect the influence of using anticoagulants (EDTA and citrate acid 3.8% toward the quantity of PRP. There are 41 subjects studied by taking 21 ml of venous blood in each of the seven tubes. Centrifugation performed twice with different speed, duration, use of anticoagulants then analyzed. This quantity between the two groups differed significantly between the PRP in EDTA group is higher 322.2 ml rather than citrate acid 3.8% group, then control group is higher 329.5 ml rather than citrate acid 3.8% group, while there is no difference between EDTA and control group. There is effect of the use of anticoagulants EDTA compared with citrate acid 3.8% in the quantity of PRP, and there was no effect using citrate acid 3.8% as anticoagulants in quantity of PRP.

  4. Corrosion behavior of Ti and TI6Al4V in citrate buffers containing fluoride ions

    Directory of Open Access Journals (Sweden)

    Anelise Marlene Schmidt

    2010-03-01

    Full Text Available The effect of fluoride ions concentration on the electrochemical behavior of Ti grade 2 and Ti6Al4V in citrate buffers was studied. Open circuit potential (OCP measurements and voltammetric studies of the samples in the fluoride containing citrate buffers revealed a dissolution process when the pH falls below 5.0 and the NaF content is higher than 0.01 M. However, in citrate pH 7.6 the materials showed a passive behavior even in 0.1 M NaF. Some micrographs of Ti grade 2 obtained after longer immersion times in citrate pH 5.0 with 0.01 M NaF showed a surface attack. EIS (Electrochemical Impedance Sprectroscopy data obtained at the OCP revealed that the film resistance decreases when the immersion time is increased in pH 5.0 containing 0.1 M NaF. In the citrate pH 7.6 the EIS data indicated a two-layer model of an oxide film consisting of a more compact inner layer and a porous outer layer. On the other hand, the EIS results in citrate pH 4.0 change significantly when the fluoride ions concentration increases from 0.01 to 0.05 M. The electrochemical data revealed that the corrosion behavior of Ti grade 2 and Ti6Al4V in the citrate buffers depends on the pH, the fluoride content and the exposure time.

  5. The evidence for clinically significant bias in plasma glucose between liquid and lyophilized citrate buffer additive.

    Science.gov (United States)

    Juricic, Gordana; Saracevic, Andrea; Kopcinovic, Lara Milevoj; Bakliza, Ana; Simundic, Ana-Maria

    2016-12-01

    Citrate buffer additive has been suggested to be of supreme performance in inhibiting glycolysis. However, there is little evidence in the literature regarding the comparability of glucose concentrations in liquid and lyophilized citrate buffer containing tubes. The aim of this study was to compare glucose concentrations in tubes containing liquid (Glucomedics) and lyophilized citrate buffer (Terumo VENOSAFE™ Glycemia) additive, measured immediately after centrifugation. Blood was collected from forty volunteers into both Glucomedics and Venosafe Glycemia tubes. Blood was centrifuged within 15min from venipuncture and glucose concentration was measured immediately after centrifugation, on the Abbott Architect analyzer. Differences between glucose concentrations in Glucomedics and Terumo tubes were tested using the paired t-test. Mean bias was calculated and compared to recommended quality specification for glucose (i.e. 2.2%). Glucose concentration in Terumo tubes was 3.4% lower than in Glucomedics tubes (Pglucose concentrations in liquid and lyophilized citrate buffer additive tubes (Glucomedics vs. Terumo tubes) measured immediately after centrifugation. This difference may affect the patient outcome due to the misclassification of diabetes. Copyright © 2016 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

  6. Acid-base characteristics of bromophenol blue-citrate buffer systems in the amorphous state.

    Science.gov (United States)

    Li, Jinjiang; Chatterjee, Koustuv; Medek, Ales; Shalaev, Evgenyi; Zografi, George

    2004-03-01

    In this study, we have examined the acid-base characteristics of various citrate buffer systems alone and in the presence of the pH indicator dye, bromophenol blue, in aqueous solution, and after lyophilization to produce amorphous material. Fourier transform Raman and solid-state nuclear magnetic resonance spectroscopy have been used to monitor the ratio of ionized to un-ionized citric acid under various conditions, as a function of initial pH in the range of 2.65-4.28. Ultraviolet-visible spectrophotometry was used to probe the extent of proton transfer of bromophenol blue in the citrate buffer systems in solution and the amorphous state. Spectroscopic studies indicated greater ionization of citric acid and bromophenol blue in solution and the solid state with increasing initial solution pH, as expected. Fourier transform Raman measurements indicated the same ratio of ionized to un-ionized citrate species in solution, frozen solution, and the amorphous state. It is shown that the ratio of species at any particular initial pH is primarily determined by the amount of sodium ion present so as to maintain electroneutrality and not necessarily to the fact that pH and pK(a) remain unchanged during freezing and freeze drying. Indeed, for bromophenol blue, the relative ultraviolet-visible intensities for ionized and un-ionized species in the amorphous sample were different from those in solution indicating that the extent of protonation of bromophenol blue was significantly lower in the solid samples. It is concluded that under certain conditions there can be significant differences in the apparent hydrogen activity of molecules in amorphous systems. Copyright 2004 Wiley-Liss, Inc. and the American Pharmacists Association

  7. Effects of EDTA on the electronic properties of passive film formed on Fe-20Cr in pH 8.5 buffer solution

    International Nuclear Information System (INIS)

    Cho, Eun Ae; Kwon, Hyuk Sang; Beranrd, Frederic

    2003-01-01

    The electronic properties of the passive film formed on Fe-20Cr ferritic stainless steel in pH 8.5 buffer solution containing 0.05 M EDTA (ethylene diammine tetraacetic acid) were examined by the photocurrent measurements and Mott-Schottky analysis for the film. XPS depth profile for the film demonstrated that Cr content in the outermost layer of the passive film was higher in the solution with EDTA than that in the solution without EDTA, due to selective dissolution of Fe by EDTA. In the solution with EDTA, the passive film showed characteristics of an amorphous or highly disordered n-type semiconductor. The band gap energies of the passive film are estimated to be ∼ 3.0 eV, irrespective of film formation potential from 0 to 700 mV SCE and of presence of EDTA. However, the donor density of the passive film formed in the solution with EDTA is much higher than that formed in the solution without EDTA, due to an increase in oxygen vacancy resulted from the dissolution of Fe-oxide in the outermost layer of the passive film. These results support the proposed model that the passive film formed on Fe-20Cr in pH 8.5 buffer solution mainly consists of Cr-substituted γ-Fe 2 O 3

  8. Experimental Determination of Lead Interactions with Citrate and EDTA in NaCl and MgCl2 Solutions to High Ionic Strength and Its Applications.

    Energy Technology Data Exchange (ETDEWEB)

    Xiong, Yongliang [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States). Carlsbad Programs Group; Kirkes, Leslie Dawn [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States). Carlsbad Programs Group; Westfall, Terry [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States). Carlsbad Programs Group; Marrs, Cassandra [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States). Carlsbad Programs Group; Knox, Jandi [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States). Carlsbad Programs Group; Burton, Heather Lynn [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States). Carlsbad Programs Group

    2017-09-01

    For this study, the interactions of lead with citrate and ethylenediaminetetraacetate (EDTA) are investigated based on solubility measurements as a function of ionic strength at room temperature (22.5 ± 0.5°C) in NaCl and MgCl2 solutions. The formation constants (log β10 ) for Pb[C3H5O(COO)3]– (abbreviated as PbCitrate) and Pb[(CH2COO)2N(CH2)2N(CH2COO)2)]2– (abbreviated as PbEDTA2–) Pb2+ + [C3H5O(COO)3]3– = Pb[C3H5O(COO)3] (1) Pb2+ + (CH2COO)2N(CH2)2N(CH2COO)2)4- = Pb[(CH2COO)2N(CH2)2N(CH2COO)2)]2– (2) are evaluated as 7.28 ± 0.18 (2σ) and 20.00 ± 0.20 (2σ), respectively, with a set of Pitzer parameters describing the specific interactions in NaCl and MgCl2 media. Based on these parameters, the interactions of lead with citrate and EDTA in various low temperature environments can be accurately modelled.

  9. New EDTA determination method based on ion chromatography with suppressed conductimetric detection

    International Nuclear Information System (INIS)

    Gyoergy Patzay; Yahya Ramadan; Csilla Tonko

    2014-01-01

    A novel direct method for the determination of EDTA in alkaline radioactive evaporator residue solution was developed and validated based on ion chromatography with suppressed conductimetric detection and anion exchange columns (A Supp 4, 4 mm × 250 mm and A Supp 5, 4 mm × 150 mm). The yttrium-EDTA complex resulted one single chromatographic peak in the eluent and allowed the correct determination of EDTA in an alkaline, high concentration radioactive waste water. Depending on coexisting substances, suitable eluent is 10.0 mM carbonate buffer/pH 10.6 or 10.75 (t R ,Y-EDTA = 7.01 and 6.4 min, respectively). For 10.0 mM carbonate buffer/pH 10.6 and isocratic flow rate of 1.0 cm 3 /min, a linear calibration curve was obtained from 5 to 40 mg/dm 3 (r > 0.999) EDTA. Good resolution was achieved from commonly coexisting anions (chloride, nitrite, nitrate, sulphate, phosphate, bromide and citrate). The developed simple ion chromatographic method was applied for the assay of EDTA in various radioactive alkaline solutions. (author)

  10. Synthesis and characterization particles of Ba{sub 0,50}Sr{sub 0,50}Co{sub 0,80}Fe{sub 0,20}O{sub 3} obtained by the citrate-EDTA technique; Sintese e caracterizacao de particulados de Ba{sub 0,50}Sr{sub 0,50}Co{sub 0,80}Fe{sub 0,20}O{sub 3} obtidos pela tecnica dos citratos-EDTA

    Energy Technology Data Exchange (ETDEWEB)

    Bonturim, E; Vargas, R A; Andreoli, M; Seo, E S.M., [Instituto de Pesquisas Energeticas e Nucleares (CCTM/IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Centro de Ciencia e Tecnologia de Materiais

    2010-07-01

    The Ba{sub (1-x)}Sr{sub (x)}Co{sub (1-y)}Fe{sub (y)}O{sub (3)} (BSCF) has been studied as a cathode material for Intermediate Temperature Solid Oxide Fuel Cell, due to its better ion and electron conduction. This work aims to study the synthesis of the compound obtained from the citrate-EDTA technique. Thermogravimetric analysis indicated the formation of the compound above 800 deg C. The materials calcined at temperatures of 700, 800 and 900 deg C for 5 h showed cubic pseudo-perovskite structure, according to the literature. By analysis of X-ray fluorescence were obtained powders with nominal chemical composition in the temperature range studied. The micrographs obtained by SEM and particle size distribution analysis showed the formation of particle with diameters below 1 micron. (author)

  11. Complexation of neptunium(V) by salicylate, phthalate and citrate ligands in a pH 7.5 phosphate buffered system

    International Nuclear Information System (INIS)

    Rees, T.F.; Daniel, S.R.

    1984-01-01

    Conditional stability constants, enthalpies and entropies of complexation at pH 7.5 and ionic strength 0.1 have been determined for neptunium(V) complexes of phosphate, salicylate, phthalate and citrate. Results are given and discussed. At pH 7.5 salicylate does not form a complex with neptunium(V) due to the low charge density of the NpO 2 + ion and incomplete ionization of the salicylate ion. In all cases, only 1:1 complexes were identified. (U.K.)

  12. Avaliação das propriedades do Ba0,50Sr0,50Co0,80Fe0,20O3-d para células a combustível de óxido sólido de temperatura intermediária obtido pelo método citratos-EDTA Evaluation of the properties of Ba0,50Sr0.50Co0.80Fe0.20O3-d obtained by the citrate-EDTA method for intermediate temperature solid oxide fuel cell

    Directory of Open Access Journals (Sweden)

    E. Bonturim

    2013-03-01

    Full Text Available Ba0,50Sr0,50Co0,80Fe0,20O3-d (BSCF apresenta propriedades físicas, químicas e microestruturais adequadas para compor o cátodo de uma célula a combustível de óxido sólido de temperatura intermediária (ITSOFC. Este trabalho tem por objetivo a síntese e a caracterização do BSCF obtido pelo método dos citrados-EDTA. Os resultados obtidos por difração de raios X (DRX indicaram fases secundárias para o material calcinado a 700 e 800 ºC e fase única com estrutura cristalina do tipo perovskita para 900 ºC. As micrografias obtidas por microscopia eletrônica de varredura dos particulados evidenciou a formação de aglomerados de tamanho Ba0.50Sr0.50Co0.80Fe0.20O3-d (BSCF presents physical, chemical and microstructural properties suitable to form the cathode of Intermediate Temperature Solid Oxide Fuel Cell (ITSOFC. This work aims the synthesis and characterization of BSCF, obtained by the citrate-EDTA method. The X-ray diffraction results indicate secondary phases for the material calcined at 700 and 800 °C and single phase with perovskite crystalline structure at 900 °C. The SEM-FEG particles micrographs show the formation of < 20 µm clusters. The dilatometric analysis of pellets indicates the sintering temperature at ~ 1050 °C. XRD results of the sintered samples show perovskite single phase. The SEM micrographs confirmed the formation of higher porosity in the samples sintered at 1000 °C/1 h using powders calcined at 900 °C.

  13. Buffer capacity of biologics--from buffer salts to buffering by antibodies.

    Science.gov (United States)

    Karow, Anne R; Bahrenburg, Sven; Garidel, Patrick

    2013-01-01

    Controlling pH is essential for a variety of biopharmaceutical process steps. The chemical stability of biologics such as monoclonal antibodies is pH-dependent and slightly acidic conditions are favorable for stability in a number of cases. Since control of pH is widely provided by added buffer salts, the current study summarizes the buffer characteristics of acetate, citrate, histidine, succinate, and phosphate buffers. Experimentally derived values largely coincide with values calculated from a model that had been proposed in 1922 by van Slyke. As high concentrated protein formulations become more and more prevalent for biologics, the self-buffering potential of proteins becomes of relevance. The current study provides information on buffer characteristics for pH ranges down to 4.0 and up to 8.0 and shows that a monoclonal antibody at 50 mg/mL exhibits similar buffer capacity as 6 mM citrate or 14 mM histidine (pH 5.0-6.0). Buffer capacity of antibody solutions scales linearly with protein concentration up to more than 200 mg/mL. At a protein concentration of 220 mg/mL, the buffer capacity resembles the buffer capacity of 30 mM citrate or 50 mM histidine (pH 5.0-6.0). The buffer capacity of monoclonal antibodies is practically identical at the process relevant temperatures 5, 25, and 40°C. Changes in ionic strength of ΔI=0.15, in contrast, can alter the buffer capacity up to 35%. In conclusion, due to efficient self-buffering by antibodies in the pH range of favored chemical stability, conventional buffer excipients could be dispensable for pH stabilization of high concentrated protein solutions. Copyright © 2013 American Institute of Chemical Engineers.

  14. EDTA-S: A novel root conditioning agent

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    S Srirangarajan

    2012-01-01

    Full Text Available Background: To evaluate the efficacy of 15% ethylenediaminetetraacetic acid (EDTA-S (EDTA with soft soap preparation for the removal of smear layer at human root surfaces. Materials and Methods: Twenty teeth indicated for extraction due to periodontal disease were sectioned using high speed cylindrical bur under copious irrigation. The root surfaces were instrumented with Gracey 7-8 curette (Hu-Friedy, 12 times to induce an "experimental smear layer". Following root planning, the root surface was cut using diamond disc and separated from the crown. Samples were randomly distributed into five groups. One group was control, saline and test groups were EDTA 15% alone, by active and passive applications (groups 2 and 3, and EDTA 15%+soft soap, by active and passive applications (groups 4 and 5. Specimens were then subjected to scanning electron microscope study. Smear layer removal was evaluated according to Sampaio et al., index. Results: EDTA-S removed the smear layer better than plain EDTA and the control group, while active application of the root conditioning agent had significant difference than the passive application of the agent. Conclusion: EDTA-S has favorable benefits over EDTA alone, and active application is better in comparison with passive application of root conditioning agent. Clinical Relevance: Removal of smear layer has been considered as an important step in periodontal regenerative therapy. Scaling and root planning alone with saline irrigation does not remove the smear layer. EDTA is a commonly used root conditioning agent in periodontal therapy. The addition of a detergent to EDTA proved to remove smear layer more efficiently than EDTA alone.

  15. Citrat og nyresten

    DEFF Research Database (Denmark)

    Osther, P J

    1993-01-01

    Citrate is an important naturally occurring inhibitor of calcium stone formation in urine. Urinary citrate excretion was examined in 43 consecutive patients with recurrent idiopathic calcium nephrolithiasis and in 50 normal controls by a specific enzymatic technique. Hypocitraturia (<1.6 mmol/24h...

  16. Artificial citrate operon and Vitreoscilla hemoglobin gene enhanced mineral phosphate solubilizing ability of Enterobacter hormaechei DHRSS.

    Science.gov (United States)

    Yadav, Kavita; Kumar, Chanchal; Archana, G; Kumar, G Naresh

    2014-10-01

    Mineral phosphate solubilization by bacteria is mediated through secretion of organic acids, among which citrate is one of the most effective. To overproduce citrate in bacterial systems, an artificial citrate operon comprising of genes encoding NADH-insensitive citrate synthase of E. coli and Salmonella typhimurium sodium-dependent citrate transporter was constructed. In order to improve its mineral phosphate solubilizing (MPS) ability, the citrate operon was incorporated into E. hormaechei DHRSS. The artificial citrate operon transformant secreted 7.2 mM citric acid whereas in the native strain, it was undetectable. The transformant released 0.82 mM phosphate in flask studies in buffered medium containing rock phosphate as sole P source. In fermenter studies, similar phenotype was observed under aerobic conditions. However, under microaerobic conditions, no citrate was detected and P release was not observed. Therefore, an artificial citrate gene cluster containing Vitreoscilla hemoglobin (vgb) gene under its native promoter, along with artificial citrate operon under constitutive tac promoter, was constructed and transformed into E. hormaechei DHRSS. This transformant secreted 9 mM citric acid under microaerobic conditions and released 1.0 mM P. Thus, incorporation of citrate operon along with vgb gene improves MPS ability of E. hormaechei DHRSS under buffered, microaerobic conditions mimicking rhizospheric environment.

  17. Hydroxyapatite synthesis using EDTA.

    Science.gov (United States)

    Kang, Nak Heon; Kim, Soon Je; Song, Seung Han; Choi, Sang mun; Choi, Sik Young; Kim, Youn Jung

    2013-05-01

    Bone comprises structure of the body and consisted of inorganic substances. It exists in an organic structure in the body. Even though it is firm and has self-healing mechanism, it can be damaged by trauma, cancer, or bone diseases. Allograft can be an alternative solution for autologous bone graft. Hydroxyapatite (Ca10(PO4)6(OH)2), an excellent candidate for allograft, can be applied to bone defect area. There are several methods to produce hydroxyapatite; however, economical cost and being time consuming make the production difficult. In this study, we synthesized hydroxyapatite with EDTA. Freeze-dried bone allograft (Hans Biomed) was used as the control group. Synthesized hydroxyapatite was a rod-shaped, white powdery substance with 2- to 5-μm length and 0.5- to 1-μm width. X-ray diffraction showed the highest sharp peak at 32°C and high peaks at 25.8°C, 39.8°C, 46.8°C, 49.5°C, and 64.0°C, indicating a similar substance to the freeze-dried bone allograft. After 3 days, the cell growth of synthesized hydroxyapatite showed 1.5-fold more than did the bone allograft. Cellular and media alkaline phosphate activity increased similar to the bone allograft. In this study, we came up with a new method to produce the hydroxyapatite. It is a convenient method that can be held in room temperature and low pressure. Also, the product can be manufactured in large quantity. It can be also transformed into scaffold structure, which will perform a stronger configuration. The manufacturing method will help the bony defect patients and make future medical products.

  18. Relevance of EDTA carryover during blood collection.

    Science.gov (United States)

    Cadamuro, Janne; Felder, Thomas Klaus; Oberkofler, Hannes; Mrazek, Cornelia; Wiedemann, Helmut; Haschke-Becher, Elisabeth

    2015-07-01

    The order of draw is regarded as a preanalytical issue to prevent carryover of additives during blood collection. Our objective was to prove the theory of ethylenediaminetetraacetic acid (EDTA) carryover for a closed vacuum system and the influence of EDTA on concentrations of selected biomarkers. To test the carryover of EDTA, a blood collection with tripotassium EDTA (K3EDTA) and subsequent non-additive tubes was simulated using distilled water as substitute for blood. EDTA concentrations were measured by tandem mass spectrometry. Then we added increasing concentrations of EDTA to heparinized blood and measured routine biomarkers, thereby simulating a carryover of EDTA whole blood and pure EDTA, respectively. Additionally, we tested for EDTA contamination and biomarker alteration in samples collected from 10 healthy volunteers by a syringe with subsequent transfer into sample tubes. No EDTA contamination was detected in samples collected subsequent to a K3EDTA tube when adhering to guidelines of blood sampling. Magnesium, calcium, and potassium levels were altered by artificial K3EDTA whole-blood contamination as well as when adding 1 μL pure K3EDTA. Iron values were altered at EDTA concentrations of 4.4 mmol/L. All other parameters remained unaffected. A slight EDTA carryover was observed in syringe collection and subsequent transfer into EDTA and heparin tubes, however, without any biomarker alteration. An EDTA carryover during blood collection using a closed vacuum system is highly unlikely. Even if carryover of EDTA whole blood occurs, an absolute volume larger than 10 μL would be necessary to alter test results. However, contamination of samples with preloaded pure K3EDTA solution by severe neglect of current recommendations in blood collection may significantly alter testing results.

  19. EDTA-assisted Pb phytoextraction.

    Science.gov (United States)

    Saifullah; Meers, E; Qadir, M; de Caritat, P; Tack, F M G; Du Laing, G; Zia, M H

    2009-03-01

    Pb is one of the most widespread and metal pollutants in soil. It is generally concentrated in surface layers with only a minor portion of the total metal found in soil solution. Phytoextraction has been proposed as an inexpensive, sustainable, in situ plant-based technology that makes use of natural hyperaccumulators as well as high biomass producing crops to help rehabilitate soils contaminated with heavy metals without destructive effects on soil properties. The success of phytoextraction is determined by the amount of biomass, concentration of heavy metals in plant, and bioavailable fraction of heavy metals in the rooting medium. In general, metal hyperaccumulators are low biomass, slow growing plant species that are highly metal specific. For some metals such as Pb, there are no hyperaccumulator plant species known to date. Although high biomass-yielding non-hyperaccumulator plants lack an inherent ability to accumulate unusual concentrations of Pb, soil application of chelating agents such as EDTA has been proposed to enhance the metal concentration in above-ground harvestable plant parts through enhancing the metal solubility and translocation from roots to shoots. Leaching of metals due to enhanced mobility during EDTA-assisted phytoextraction has been demonstrated as one of the potential hazards associated with this technology. Due to environmental persistence of EDTA in combination with its strong chelating abilities, the scientific community is moving away from the use of EDTA in phytoextraction and is turning to less aggressive alternative strategies such as the use of organic acids or more degradable APCAs (aminopolycarboxylic acids). We have therefore arrived at a point in phytoremediation research history in which we need to distance ourselves from EDTA as a proposed soil amendment within the context of phytoextraction. However, valuable lessons are to be learned from over a decade of EDTA-assisted phytoremediation research when considering the

  20. Toxicity Thresholds Based on EDTA Extractable Nickel and Barley Root Elongation in Chinese Soils

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    Guangyun Zhu

    2018-04-01

    Full Text Available The uncertainty in the risk assessment of trace metal elements in soils when total metal contents are used can be decreased by assessing their availability and/or extractability when the soils have a high background value or different sources of trace metal elements. In this study, the added water-soluble nickel (Ni toxicity to barley root elongation was studied in 17 representative Chinese soil samples with and without artificial rainwater leaching. The extractability of added Ni in soils was estimated by three sequential extractions with ethylenediaminetetraacetic acid (EDTA. The results showed that the effective concentration of EDTA extractable Ni (EC50, which caused 50% inhibition of barley root elongation, ranged from 46 to 1019 mg/kg in unleached soils and 24 to 1563 mg/kg in leached soils. Regression models for EDTA extractable Ni and total Ni added to soils against soil properties indicated that EDTA extractable Ni was significantly correlated with the total Ni added to soils and that pH was the most important control factor. Regression models for toxicity thresholds based on EDTA extractable Ni against soil properties showed that soil citrate dithionate extractable Fe was more important than soil pH in predicting Ni toxicity. These results can be used to accurately assess the risk of contaminated soils with high background values and/or different Ni sources.

  1. Citric complexes, neodymium citrate and americium citrate

    International Nuclear Information System (INIS)

    Bouhlassa, Saidati.

    1981-06-01

    The behaviour of neodymium and americium has been studied in citric aqueous medium by two methods: solvent extraction of elements at tracer scale as chelates and by potentiometry. So range of pH and concentrations of elements and citric acid never reached before have been explored: 10 -7 -1 M, 10 -10 -3 , Csub(H3 Cit) -1 M, 1 2 O; AmCit, xH 2 O; NdCit 2 Co(NH 3 ) 6 , 8H 2 O; AmCit 2 Co(NH 3 ) 6 , xH 2 O and Nd 3 (OH) 4 (Cit) 4 NH 4 (Co(NH 3 ) 6 ) 2 , 18H 2 O. Their spectroscopic and crystallographic characteristics have been listed and studied. The nephelauxetic effect has been estimated from citric complexes as well as from citrates of these elements. The structure of the complexes in solution has been discussed on the basis of analysis of hypersensitive transition in different complexes [fr

  2. Characterizing RecA-independent induction of Shiga toxin2-encoding phages by EDTA treatment.

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    Lejla Imamovic

    Full Text Available BACKGROUND: The bacteriophage life cycle has an important role in Shiga toxin (Stx expression. The induction of Shiga toxin-encoding phages (Stx phages increases toxin production as a result of replication of the phage genome, and phage lysis of the host cell also provides a means of Stx toxin to exit the cell. Previous studies suggested that prophage induction might also occur in the absence of SOS response, independently of RecA. METHODOLOGY/PRINCIPAL FINDINGS: The influence of EDTA on RecA-independent Stx2 phage induction was assessed, in laboratory lysogens and in EHEC strains carrying Stx2 phages in their genome, by Real-Time PCR. RecA-independent mechanisms described for phage λ induction (RcsA and DsrA were not involved in Stx2 phage induction. In addition, mutations in the pathway for the stress response of the bacterial envelope to EDTA did not contribute to Stx2 phage induction. The effect of EDTA on Stx phage induction is due to its chelating properties, which was also confirmed by the use of citrate, another chelating agent. Our results indicate that EDTA affects Stx2 phage induction by disruption of the bacterial outer membrane due to chelation of Mg(2+. In all the conditions evaluated, the pH value had a decisive role in Stx2 phage induction. CONCLUSIONS/SIGNIFICANCE: Chelating agents, such as EDTA and citrate, induce Stx phages, which raises concerns due to their frequent use in food and pharmaceutical products. This study contributes to our understanding of the phenomenon of induction and release of Stx phages as an important factor in the pathogenicity of Shiga toxin-producing Escherichia coli (STEC and in the emergence of new pathogenic strains.

  3. Transport of EDTA into cells of the EDTA-degrading bacterial strain DSM 9103.

    Science.gov (United States)

    Witschel, M; Egli, T; Zehnder, A J; Wehrli, E; Spycher, M

    1999-04-01

    In the bacterial strain DSM 9103, which is able to grow with the complexing agent EDTA as the sole source of carbon, nitrogen and energy, the transport of EDTA into whole cells was investigated. EDTA uptake was found to be dependent on speciation: free EDTA and metal-EDTA complexes with low stability constants were readily taken up, whereas those with stability constants higher than 1016 were not transported. In EDTA-grown cells, initial transport rates of CaEDTA showed substrate-saturation kinetics with a high apparent affinity for CaEDTA (affinity constant Kt= 0.39 microM). Several uncouplers had an inhibitory effect on CaEDTA transport. CaEDTA uptake was also significantly reduced in the presence of an inhibitor of ATPase and the ionophore nigericin, which dissipates the proton gradient. Valinomycin, however, which affects the electrical potential, had little effect on uptake, indicating that EDTA transport is probably driven by the proton gradient. Of various structurally related compounds tested only Ca2+-complexed diethylenetriaminepentaacetate (CaDTPA) competitively inhibited CaEDTA transport. Uptake in fumarate-grown cells was low compared to that measured in EDTA-grown bacteria. These results strongly suggest that the first step in EDTA degradation by strain DSM 9103 consists of transport by an inducible energy-dependent carrier. Uptake experiments with 45Ca2+ in the presence and absence of EDTA indicated that Ca2+ is transported together with EDTA into the cells. In addition, these transport studies and electron-dispersive X-ray analysis of electron-dense intracellular bodies present in EDTA-grown cells suggest that two mechanisms acting simultaneously allow the cells to cope with the large amounts of metal ions taken up together with EDTA. In one mechanism the metal ions are excreted, in the other they are inactivated intracellularly in polyphosphate granules.

  4. Metal decomposition rates or 111In-DPTA and EDTA conjugates of monoclonal antibodies in vivo

    International Nuclear Information System (INIS)

    Goodwin, D.A.; McTigue, M.; Chaovapong, W.; Meares, C.F.; McCall, M.J.

    1986-01-01

    We have studied the metal chelate decomposition rates in vivo in both 111 In-labelled benzyl EDTA and DTPA (bicyclic anhydride) conjugates of monoclonal anti-IAsup(k) IgG2a with identical Kα = 1 x 10 11 M -1 in both Ag + ve and Ag -ve mice. Twenty μCi was given i.v. and whole body counting done immediately and daily for 10 days. Half the mice in each group received i.p. injections of 5.0 mg CaNa 2 EDTA chase (Versenate) to facilitate urinary excretion of free 111 In. 50% of control 111 In-citrate remained at nine days but only 8% with chase. No significant loss of 111 In with chase occurred with C 1 substituted EDTA conjugates. A 19% increase in excretion was demonstrated with the chase in mice give DTPA conjugates (1.9% per day). While this will not interfere with radioimmunoimaging up to 24 h after injection, waiting periods of a week or longer will produce significant background of free 111 In in the reticuloendothelial system, RES. 111 In-EDTA stability was important in accurate metabolic rate measurements of anti-IAsup(k); T1/2 = 7.0 days in Ag-ve mice, T1/2 = 9.3 days in Ag-ve mice. (author)

  5. Buffers Plus

    Science.gov (United States)

    Ramette, Richard W.

    1998-11-01

    In 1989 JCE Software published The Acid-Base Package: A Collection of Useful Programs for Proton Transfer Systems (Ramette, R. W. J. Chem. Educ. Software 1989, 2B No. 2). This DOS program has been fully upgraded by the same author to the world of Windows 95. Buffers Plus takes advantage of a modern user interface and offers many new options not possible in the original version.

  6. Buffer fluid

    Energy Technology Data Exchange (ETDEWEB)

    Mirzadzhanzade, A Kh; Dedusanko, G Ya; Dinaburg, L S; Markov, Yu M; Rasizade, Ya N; Rozov, V N; Sherstnev, N M

    1979-08-30

    A drilling fluid is suggested for separating the drilling and plugging fluids which contains as the base increased solution of polyacrylamide and additive. In order to increase the viscoelastic properties of the liquid with simultaneous decrease in the periods of its fabrication, the solution contains as an additive dry bentonite clay. In cases of the use of a buffer fluid under conditions of negative temperatures, it is necessary to add to it table salt or ethylene glycol.

  7. Effects of Na4EDTA and EDTA on seeded precipitation of sodium aluminate solution

    Institute of Scientific and Technical Information of China (English)

    吕保林; 陈启元; 尹周澜; 胡慧萍

    2010-01-01

    Na4EDTA and EDTA were adopted as new additives to intensify the seeded precipitation process of sodium aluminate solution. The effects of the two additives at certain concentrations on the seeded precipitation rate of sodium aluminate solution, particle size distribution (PSD) and morphology of precipitated gibbsite were investigated using titration method, particle size analyzer and scanning electron microscope (SEM), respectively. The results show that the two additives can accelerate the seeded precipitation rate of sodium aluminate solution. At relatively high concentration, the facilitative effect of EDTA on sodium aluminate solution is more obvious than that of Na4EDTA. EDTA makes gibbsite particles thinner than Na4EDTA. The Na+ and H+ result in the different effects on the seeded precipitation rate of sodium aluminate solution in spite of the same EDTA anion in the two additives.

  8. Buffer-free therapeutic antibody preparations provide a viable alternative to conventionally buffered solutions: from protein buffer capacity prediction to bioprocess applications.

    Science.gov (United States)

    Bahrenburg, Sven; Karow, Anne R; Garidel, Patrick

    2015-04-01

    Protein therapeutics, including monoclonal antibodies (mAbs), have significant buffering capacity, particularly at concentrations>50 mg/mL. This report addresses pH-related issues critical to adoption of self-buffered monoclonal antibody formulations. We evaluated solution conditions with protein concentrations ranging from 50 to 250 mg/mL. Samples were both buffer-free and conventionally buffered with citrate. Samples were non-isotonic or adjusted for isotonicity with NaCl or trehalose. Studies included accelerated temperature stability tests, shaking stability studies, and pH changes in infusion media as protein concentrate is added. We present averaged buffering slopes of capacity that can be applied to any mAb and present a general method for calculating buffering capacity of buffer-free, highly concentrated antibody liquid formulations. In temperature stability tests, neither buffer-free nor conventionally buffered solution conditions showed significant pH changes. Conventionally buffered solutions showed significantly higher opalescence than buffer-free ones. In general, buffer-free solution conditions showed less aggregation than conventionally buffered solutions. Shaking stability tests showed no differences between buffer-free and conventionally buffered solutions. "In-use" preparation experiments showed that pH in infusion bag medium can rapidly approximate that of self-buffered protein concentrate as concentrate is added. In summary, the buffer capacity of proteins can be predicted and buffer-free therapeutic antibody preparations provide a viable alternative to conventionally buffered solutions. Copyright © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Liquid growth hormone: preservatives and buffers

    DEFF Research Database (Denmark)

    Kappelgaard, Anne-Marie; Anders, Bojesen; Skydsgaard, Karen

    2004-01-01

    injection are dependent on the preservative used in the formulation and the concentration of GH. Injection pain may also be related to the buffer substance and injection volume. A liquid formulation of GH, Norditropi SimpleXx, has been developed that dispenses with the need for reconstitution before...... solution. More pain was also reported following large volume injections and following injections with solutions containing high protein concentrations. In summary, optimization of the preservative and buffer content of a liquid GH formulation may reduce injection pain and lead to improved patient...... administration. The formulation uses phenol (3 mg/ml) as a preservative (to protect product from microbial degradation or contamination) and histidine as a buffer. Alternative preservatives used in other GH formulations include m-cresol (9 mg/ml) and benzyl alcohol (3-9 mg/ml). Buffering agents include citrate...

  10. Comparison of Five Nuclear Isolation Buffers for Flow Cytometric ...

    African Journals Online (AJOL)

    Jocky

    2012-02-23

    Feb 23, 2012 ... species. A systematic comparison of nuclear lysis buffers has been ... All experiments were carried out with 3 replicates (n = 3) per treatment. ... Na2EDTA, 0.5 mM spermine.4HCl, 80 mM KCl, 20 mM NaCl, 0.1%. (v/v) Triton ...

  11. K2-EDTA and K3-EDTA Greiner Tubes for HbA1c Measurement.

    Science.gov (United States)

    Vrtaric, Alen; Filipi, Petra; Hemar, Marina; Nikolac, Nora; Simundic, Ana-Maria

    2016-02-01

    To determine whether K2-ethylenediaminetetraacetic acid (EDTA) and K3-EDTA Greiner tubes could be used interchangeably for glycosylated hemoglobin, type A1C (HbA1c) measurement via the Abbott Laboratories ARCHITECT chemiluminescent microparticle HbA1c assay on the ARCHITECT i2000SR immunoanalyzer at our university hospital. We drew blood from a total of 45 outpatients into plastic Greiner Vacuette tubes, some of which were lined with K2-EDTA and others with K3-EDTA anticoagulant. Data are presented as median and interquartile range values. We used the Wilcoxon test and Passing-Bablok regression for tube comparison. For K2-EDTA tubes median HbA1c concentration was 54 mmol/mol (41 to 71 mmol/mol) and for K3-EDTA tubes 56 mmol/mol (43 to 69 mmol/mol). There was no statistically significant difference between K2-EDTA and K3-EDTA (bias= -1.29 mmol/mol; P = 0.24). Passing-Bablok regression showed that there is no constant and proportional error: y = -0.23 (95% CI[-3.52 to 0.69]) + 1.00( 95% CI[0.98 to 1.06]) x. In this study, we provide evidence for the lack of any clinically and statistically significant bias between K2-EDTA and K3-EDTA HbA1c measurements. Thus, Greiner tubes lined with K2-EDTA and those lined with K3-EDTA can safely be used interchangeably to measure HbA1c via the Abbott Laboratories ARCHITECT assay. © American Society for Clinical Pathology, 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  12. Efficacy of egg-yolk citrate extender fortified with aqueous garlic ...

    African Journals Online (AJOL)

    An experiment was designed to harness the potential of aqueous fresh and dried garlic extracts supplement in egg yolk extender for rooster semen to improve fertility and hatchability of egg. Aqueous extract of fresh and dry garlic were obtained and supplemented into egg yolk-citrate buffer at 0,1, 2, 3, 4, 5, 6 and 7% for ...

  13. Enhanced phytoextraction: II. Effect of EDTA and citric acid on heavy metal uptake by Helianthus annuus from a calcareous soil.

    Science.gov (United States)

    Lesage, E; Meers, E; Vervaeke, P; Lamsal, S; Hopgood, M; Tack, F M G; Verloo, M G

    2005-01-01

    High biomass producing plant species, such as Helianthus annuus, have potential for removing large amounts of trace metals by harvesting the aboveground biomass if sufficient metal concentrations in their biomass can be achieved However, the low bioavailability of heavy metals in soils and the limited translocation of heavy metals to the shoots by most high biomass producing plant species limit the efficiency of the phytoextraction process. Amendment of a contaminated soil with ethylene diamine tetraacetic acid (EDTA) or citric acid increases soluble heavy metal concentrations, potentially rendering them more available for plant uptake. This article discusses the effects of EDTA and citric acid on the uptake of heavy metals and translocation to aboveground harvestable plant parts in Helianthus annuus. EDTA was included in the research for comparison purposes in our quest for less persistent alternatives, suitable for enhanced phytoextraction. Plants were grown in a calcareous soil moderately contaminated with Cu, Pb, Zn, and Cd and treated with increasing concentrations of EDTA (0.1, 1, 3, 5, 7, and 10 mmol kg(-1) soil) or citric acid (0.01, 0.05, 0.25, 0.442, and 0.5 mol kg(-1) soil). Heavy metal concentrations in harvested shoots increased with EDTA concentration but the actual amount of phytoextracted heavy metals decreased at high EDTA concentrations, due to severe growth depression. Helianthus annuus suffered heavy metal stress due to the significantly increased bioavailable metal fraction in the soil. The rapid mineralization of citric acid and the high buffering capacity of the soil made citric acid inefficient in increasing the phytoextracted amounts of heavy metals. Treatments that did not exceed the buffering capacity of the soil (heavy metal concentrations. Treatments with high concentrations resulted in a dissolution of the carbonates and compaction of the soil. These physicochemical changes caused growth depression of Helianthus annuus. EDTA and citric

  14. 21 CFR 582.5195 - Calcium citrate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Calcium citrate. 582.5195 Section 582.5195 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Supplements 1 § 582.5195 Calcium citrate. (a) Product. Calcium citrate. (b) Conditions of use. This substance...

  15. 21 CFR 582.6195 - Calcium citrate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Calcium citrate. 582.6195 Section 582.6195 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Calcium citrate. (a) Product. Calcium citrate. (b) Conditions of use. This substance is generally...

  16. 21 CFR 582.1195 - Calcium citrate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Calcium citrate. 582.1195 Section 582.1195 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1195 Calcium citrate. (a) Product. Calcium citrate. (b) Conditions of use. This substance is...

  17. Buffer mass test - Buffer materials

    International Nuclear Information System (INIS)

    Pusch, R.; Boergesson, L.

    1982-08-01

    Commercial Na bentonite (MX-80) is the clay component of the buffer material in the heater holes as well of the tunnel backfill. Important characteristics are the clay content, liquid limit, X-ray diffraction pattern, water content, and degree of granulation. The ballast material consists of quartz-rich sand and feldspar-rich filler. The preparation of highly compacted bentonite for the near-field isolation of the canister was made by using isostatic compaction technique. The resulting dense bentonite core was cut into regularly shaped blocks which were arranged around each heater and lowered as one unit - heavily instrumented - in the respective deposition holes. For three of the six holes a narrow slot was left open between the bentonite stack and the rock; for the remaining ones a wider slot was chosen with a fill of soft bentonite powder. Both arrangements are expected to yield an ultimate bulk density which is sufficiently high to fulfil the requirement of a negligible permeability and a sufficient swelling pressure as well as heat conductivity, which are the essential parameters. The tunnel backfill, which consists of a mixture of suitably graded ballast material and MX-80 powder, has a considerably lower swelling pressure and heat conductivity, and a higher permeability, all these parameters still within the requirements of the KBS 2 concept. The various zones with different bentonite/sand ratios and the technique to apply them are described in the final part of the report. (Author)

  18. Biodegradation of PuEDTA and Impacts on Pu Mobility

    International Nuclear Information System (INIS)

    Xun, Luying; Bolton, Jr. Harvey

    2001-01-01

    Ethylenediaminetetraacetate (EDTA) and nitrilotriacetate (NTA) are synthetic chelating agents, which can form strong water-soluble complexes with radionuclides and metals and has been used to decontaminate and process nuclear materials. Synthetic chelating agents were co-disposed with radionuclides (e.g., 60Co, Pu) and heavy metals enhancing their transport in the subsurface. An understanding of EDTA biodegradation is essential to help mitigate enhanced radionuclide transport by EDTA. The objective of this research is to develop fundamental data on factors that govern the biodegradation of radionuclide-EDTA. These factors include the dominant EDTA aqueous species, the biodegradation of various metal-EDTA complexes, the uptake of various metal-EDTA complexes into the cell, the distribution and mobility of the radionuclide during and after EDTA biodegradation, and the enzymology and genetics of EDTA biodegradation

  19. Carbon dioxide sorption on EDTA modified halloysite

    Directory of Open Access Journals (Sweden)

    Waszczuk Patrycja

    2016-01-01

    Full Text Available In this paper the sorption study of CO2 on EDTA surface modified halloysite was conducted. In the paper chemical modification of halloysite from the Dunino deposit (Poland and its influence on sorption of CO2 are presented. A halloysite samples were washed with water-EDTA 1% solution, centrifuged to separate liquid and impurities and dried. The samples were tested for the sorption capacity using a manometric method with pressure up to 3 MPa. A Langmuir adsorption model was fitted to the data. The results showed that EDTA had a limited effect on the increase of sorption potential at low pressure and the samples exhibited similar results to that ones treated solely with the water solution.

  20. Crown ether derivatives of EDTA: Pt. 6

    International Nuclear Information System (INIS)

    Liu Zhongqun; Qin Shengying; Chen Shaojin; Tan Lin

    1988-01-01

    EDTA-diaminodibenzo-18-crown-6 (cis- and trans-) condensation polymer is a new compound of crown ether derivatives of EDTA. In this paper the adsorption behaviors of U(IV) and U(VI) on this polymer from chloride solutions and effects of hydrochloric acid concentrations, salting-out agents and organic solvents on distribution coefficient (K d ) of uranium are investigated. Adsorption mechanism of uranyl ion (UO 2 2+ ) on this polymer was studied with IR spectra and by means of the adsorption behaviors of compounds of similar structure. Experimental results show that both polyether section and carboxyl groups in EDTA-diaminodibenzo-18-crown-6 take part in complexation with uranyl ion and synergistic effect appeared

  1. Evaluation of calcium di-sodium EDTA intramuscular injection using gamma scintigraphy against heavy metal poisoning

    International Nuclear Information System (INIS)

    Kumar, N.; Soni, S.; Mehra, L.; Mittal, G.; Nishad, D.K.; Bhatnagar, A.; Singh, T.; Ahmad, F.J.

    2010-01-01

    Full text: Heavy metals become toxic when they are not metabolized by the body and accumulate in soft tissues. These metals may enter the body through food, water, air or absorption through skin when an individual is exposed to areas with high heavy metal content such as agriculture, pharmaceutical manufacturing, paint and heavy metal industries or residential settings. Majority of population commonly get affected by heavy metal poisoning. Heavy metal poisoning is more likely to result through inhalation or ingestion route. Aim of the present study is to provide an easy, effective and controlled chelating therapy against heavy metal using Ca-disodium EDTA intramuscular injection. Ca-disodium-EDTA and Sesame oil were procured from Merck, India and Sigma Aldrich, USA respectively. Ca-Na 2 EDTA radiolabeling with 99m Tc-pertechnetate was standardized using stannous ions as reducing agent. The hypothesis of present work is to maintain effective concentration of chelating agent in blood for prolong time period. To test this hypothesis, we studied 1% Ca-Na 2 EDTA blood bioavailability after intramuscular depot administration in new zealand white rabbit. The optimized radiolabeled intramuscular formulation was evaluated for its dissolution and permeation studies in isotonic buffer solution were envisaged through radiometry. Sub-acute toxicity studies were performed after a single dose intramuscular administration of 1% Ca-Na 2 EDTA in Sprague Dawley rats. Radiolabeled Ca-disodium-EDTA (>95% labeled) was found to be fairly stable up to 24 h in physiological solution (Serum) as well as in normal saline with negligible degradation of 2.5% and 5.0% respectively, thereby indicating high stability of radiolabeled product. In-vitro data indicates that control release pattern (Cmax 24 hrs) with effective concentration up to seven days. 99m Tc-CaNa 2 EDTA retention at depot site was estimated up to 3 days by scintigraphy. Subacute toxicity studies done by histopathological

  2. Anaerobic Biotransformation and Mobility of Pu and PuEDTA

    International Nuclear Information System (INIS)

    Xun, Luying

    2005-01-01

    The objective of this report is to isolate anaerobic EDTA-degrading bacteria. Although our goal is to isolate anaerobic EDTA degraders, we initiated the experiments to include nitrilotriacetate (NTA), which is a structure homologue of EDTA. All the aerobic EDTA degraders can degrade NTA, but the isolated NTA degraders cannot degrade EDTA. Since NTA is a simpler structure homologue, it is likely that EDTA-degrading ability is evolved from NTA degradation. This hypothesis is further supported from our characterization of EDTA and NTA-degrading enzymes and genes (J. Bact. 179:1112-1116; and Appl. Environ. Microbiol. 67:688-695). The EDTA monooxygenase and NTA monooxygenase are highly homologous. EDTA monooxygenase can use both EDTA and NTA as substrates, but NTA monooxygenase can only use NTA as a substrate. Thus, we put our effort to isolate both NTA and EDTA degraders. In case, an anaerobic EDTA degrader is not immediately enriched, we will try to evolve the NTA degraders to use EDTA. Both aerobic and anaerobic enrichment cultures were set

  3. 21 CFR 172.135 - Disodium EDTA.

    Science.gov (United States)

    2010-04-01

    ..., other than black-eyed peas) 165 Promote color retention. Mayonnaise 75 Preservative. Ready-to-eat cereal... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Disodium EDTA. 172.135 Section 172.135 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN...

  4. Rate constants for the reaction of e-aq with EDTA and some metal EDTA-complexes

    International Nuclear Information System (INIS)

    Buitenhuis, R.; Bakker, C.M.N.; Stock, F.R.; Louwrier, P.W.F.

    1977-01-01

    The rate constants for the reaction e - aq + EDTA were measured as a function of the pH by the pulse-radiolysis technique. Between pH = 6and pH = 10 this rate constant can be represented by the equation k = 4.7 x 10 6 x (fraction of HEDTA 3- )+1.0 x 10 8 x (fraction H 2 EDTA 2 -)M -1 s -1 . Also the rate constants for reactions of e - aq with the following metal-EDTA complexes were measured: CuEDTA 2- , HgEDTA 2- , CoEDTA 2- , InEDTA - , NiEDTA 2- , GaEDTA - , MnEDTA 2- , ZnEDTA 2- , CdEDTA 2- , PbEDTA 2- . Ionic strength variation indicates that the reacting ions are not hydrolized to an appreciable amount at pH = 11.5. It is found that some of the products show light absorption in the region between 300 and 400 nm. (orig.) [de

  5. Functional analysis of the citrate activator CitO from Enterococcus faecalis implicates a divalent metal in ligand binding

    Directory of Open Access Journals (Sweden)

    Victor S. Blancato

    2016-02-01

    Full Text Available The regulator of citrate metabolism, CitO, from Enterococcus faecalis belongs to the FCD family within the GntR superfamily. In the presence of citrate, CitO binds to cis-acting sequences located upstream of the cit promoters inducing the expression of genes involved in citrate utilization. The quantification of the molecular binding affinities, performed by isothermal titration calorimetry (ITC, indicated that CitO has a high affinity for citrate (KD= 1.2±0.2 µM, while it did not recognize other metabolic intermediates. Based on a structural model of CitO where a putative small molecule and a metal binding site were identified, it was hypothesized that the metal ion is required for citrate binding. In agreement with this model, citrate binding to CitO sharply decreased when the protein was incubated with EDTA. This effect was reverted by the addition of Ni2+, and Zn2+ to a lesser extent. Structure-based site-directed mutagenesis was conducted and it was found that changes to alanine in residues Arg97 and His191 resulted in decreased binding affinities for citrate, as determined by EMSA and ITC. Further assays using lacZ fusions confirmed that these residues in CitO are involved in sensing citrate in vivo. These results indicate that the molecular modifications induced by a ligand and a metal binding in the C-terminal domain of CitO are required for optimal DNA binding activity, and consequently, transcriptional activation.

  6. Use of EDTA for potentiometric back titration of rare earths and analysis of their mixtures

    International Nuclear Information System (INIS)

    Zayed, M.A.; Rizk, M.S.; Khalifa, H.; Omer, W.F.

    1987-01-01

    Advantage was taken of the stoichiometric reaction between mercury(II), rare earths, alkaline earths, heavy metal ions and EDTA in urotropine buffered media to determine rare earths by back-titration of excess EDTA in the course of estimating a variety of lanthanides or analysing their binary mixture with one of the alkaline earth metals by selective control of pH; or analysing their binary mixtures with heavy metals using fluoride as a good masking agent for rare earths; or analysing their ternary mixtures with both heavy and alkaline earth metals in two steps, one by selective control of pH and the other by masking of rare earths with fluoride at lower pH to estimate the heavy metal. The procedures given are simple, rapid and extremely reliable. 19 refs. (author)

  7. Protective effect by EDTA in radiation inactivation of enzymes

    Energy Technology Data Exchange (ETDEWEB)

    Kumakura, M; Kaetsu, I

    1985-11-05

    Protective effect by EDTA in radiation inactivation of enzymes such as glucoamylase, cellulase, and urease was studied. A remarkable protective effect by EDTA was observed and had a maximum at certain EDTA concentration. The protective effect was compared with other protective agents in the irradiation of urease, in which the protective ability of EDTA was greater than those of sulfhydryl compounds such as cysteine. (author).

  8. Biodegradation of PuEDTA and Impacts on Pu Mobility

    International Nuclear Information System (INIS)

    Bolton, H. Jr.; Rai, D.; Xun, L.

    2004-01-01

    The contamination of many DOE sites by Pu presents a long-term problem because of its long half-life (240,000 yrs) and the low drinking water standard ( -12 M). EDTA was co-disposed with radionuclides (e.g., Pu, 60 Co), formed strong complexes, and enhanced radionuclide transport at several DOE sites. Biodegradation of EDTA should decrease Pu mobility. One objective of this project was to determine the biodegradation of EDTA in the presence of PuEDTA complexes. The aqueous system investigated at pH 7 (10 -4 M EDTA and 10 -6 M Pu) contained predominantly Pu(OH) 2 EDTA 2- . The EDTA was degraded at a faster rate in the presence of Pu. As the total concentration of both EDTA and PuEDTA decreased (i.e., 10 -5 M EDTA and 10 -7 M PuEDTA), the presence of Pu decreased the biodegradation rate of the EDTA. It is currently unclear why the concentration of Pu directly affects the increase/decrease in rate of EDTA biodegradation. The soluble Pu concentration decreased, in agreement with thermodynamic predictions, as the EDTA was biodegraded, indicating that biodegradation of EDTA will decrease Pu mobility when the Pu is initially present as Pu(IV)EDTA. A second objective was to investigate how the presence of competing metals, commonly encountered in geologic media, will influence the speciation and biodegradation of Pu(IV)-EDTA. Studies on the solubilities of Fe(OH) 3 (s) and of Fe(OH) 3 (s) plus PuO 2 (am) in the presence of EDTA and as a function of pH showed that Fe(III) out competes the Pu(IV) for the EDTA complex, thereby showing that Pu(IV) will not form stable complexes with EDTA for enhanced transport of Pu in Fe(III) dominated subsurface systems. A third objective is to investigate the genes and enzymes involved in EDTA biodegradation. BNC1 can use EDTA and another synthetic chelating agent nitrilotriacetate (NTA) as sole carbon and nitrogen sources. The same catabolic enzymes are responsible for both EDTA and NTA degradation except that additional enzymes are

  9. Citrate and renal calculi: an update

    Science.gov (United States)

    Pak, C. Y.

    1994-01-01

    Citrate is an inhibitor of the crystallization of stone-forming calcium salts. Hypocitraturia, frequently encountered in patients with nephrolithiasis, is therefore an important risk factor for stone formation. Potassium citrate provides physiological and physicochemical correction and inhibits new stone formation, not only in hypocitraturic calcium nephrolithiasis but also in uric acid nephrolithiasis. Inhibition of stone recurrence has now been validated by a randomized trial. Ongoing research has disclosed additional causes of hypocitraturia (sodium excess, low intestinal alkali absorption, but not primary citrate malabsorption). Moreover, new insights on potassium citrate action have been shown, notably that some of absorbed citrate escapes oxidation and contributes to the citraturic response, that ingestion with a meal does not sacrifice physiological or physicochemical action, that orange juice mimics but does not completely duplicate its actions, that potassium citrate may have a beneficial bone-sparing effect, that it may reduce stone fragments following ESWL, and that danger of aluminum toxicity is not great in subjects with functioning kidneys. Finally, the research on potassium citrate has led to two promising products, calcium citrate as an optimum calcium supplement and potassium-magnesium citrate which may be superior to potassium citrate in the management of stone disease.

  10. 21 CFR 73.2120 - Disodium EDTA-copper.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Disodium EDTA-copper. 73.2120 Section 73.2120 Food... COLOR ADDITIVES EXEMPT FROM CERTIFICATION Cosmetics § 73.2120 Disodium EDTA-copper. (a) Identity. The color additive disodium EDTA-copper is disodium [[N,N′- 1,2- ethanediylbis[N - (carboxymethyl) glycinato...

  11. Effectiveness of EDTA and Modified Salt Solution to Detach and Kill Cells from Enterococcus faecalis Biofilm.

    Science.gov (United States)

    de Almeida, Josiane; Hoogenkamp, Michel; Felippe, Wilson T; Crielaard, Wim; van der Waal, Suzette V

    2016-02-01

    Disruption of the matrix of endodontic biofilms will aid in their removal from a root canal. Therefore, the aim of this study was to investigate the efficacy of EDTA and a modified salt solution (MSS) to detach bacteria from biofilms. Forty-eight-hour-old Enterococcus faecalis biofilms were grown on glass coverslips and then treated for 1 hour by immersion in 17% EDTA or MSS. Phosphate-buffered saline served as a negative control. Then, residual biofilm cells on the substrate and the detached cells in the supernatant were collected. Viability was verified by the colony-forming unit (CFU) counting method. Propidium monoazide (PMA) treatment in conjunction with quantitative polymerase chain reaction (qPCR) was also performed to detect the presence of E. faecalis 16S ribonucleic RNA genes. Data were analyzed using 1-way analysis of variance and Tukey or Kruskal-Wallis and Dunn tests. The Pearson R test evaluated the correlation between results from CFU and PMA (α = 5%). qPCR showed that EDTA detached 99% of biofilm cells, and MSS detached 94% of biofilm cells (both P < .001). In contrast to EDTA, MSS was highly antimicrobial. The treatment promoted an ample log 7 reduction of the attached cells (P < .001), and almost no live cells were detected in the supernatant (P < .001). Positive correlations between CFU and qPCR with PMA were observed (r = 0.959 and r = 0.729). EDTA detached cells in biofilms with a minor antimicrobial effect. Besides a great antimicrobial effect, MSS also detached biofilm cells. These dispersals of biofilms give insights into new endodontic biofilm removal strategies. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  12. Immobilised metal-ion affinity chromatography purification of histidine-tagged recombinant proteins : a wash step with a low concentration of EDTA

    NARCIS (Netherlands)

    Westra, DF; Welling, GW; Koedijk, DGAM; Scheffer, AJ; The, TH; Welling-Wester, S

    2001-01-01

    Immobilised metal-ion affinity chromatography (IMAC) is widely used for the purification of recombinant proteins in which a poly-histidine tag is introduced. However, other proteins may also bind to IMAC columns. We describe the use of a washing buffer with a low concentration of EDTA (0.5 mM) for

  13. 21 CFR 184.1195 - Calcium citrate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Calcium citrate. 184.1195 Section 184.1195 Food and... Substances Affirmed as GRAS § 184.1195 Calcium citrate. (a) Calcium citrate (Ca3(C6H5O7)2·4H2O, CAS Reg. No. 813-0994-095) is the calcium salt of citric acid. It is prepared by neutralizing citric acid with...

  14. Gallium-67 citrate localization in disseminated sporotrichosis

    International Nuclear Information System (INIS)

    Moreno, A.J.; Brazier, J.M.; Baker, F.J.; Fox, B.J.; Pittman, D.L.

    1985-01-01

    A 25-year-old woman demonstrated Ga-67 citrate accumulation within a facial cutaneous lesion and two subcutaneous nodules within the right lower extremity. Cultures of the facial lesion and one of the subcutaneous nodules grew Sporothrix schenckii. Ga-67 citrate uptake has not been reported previously with this fungal infection. Ga-67 citrate scintigraphy was helpful in defining the extent of the disease, following its course, and determining the response to therapy

  15. 21 CFR 184.1625 - Potassium citrate.

    Science.gov (United States)

    2010-04-01

    ... acid with potassium hydroxide or potassium carbonate. It occurs as transparent crystals or a white... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Potassium citrate. 184.1625 Section 184.1625 Food... Specific Substances Affirmed as GRAS § 184.1625 Potassium citrate. (a) Potassium citrate (C6H5K3O7·H2O, CAS...

  16. The study of operating variables in soil washing with EDTA

    International Nuclear Information System (INIS)

    Zou Zeli; Qiu Rongliang; Zhang Weihua; Dong Hanying; Zhao Zhihao; Zhang Tao; Wei Xiange; Cai Xinde

    2009-01-01

    This study discusses the operating variables for removal of metals from soils using EDTA, including the type of EDTA, reaction time, solution pH, dose, temperature, agitation, ultrasound and number of extractions. For As, Cd, Cu, Pb and Zn, the removal efficiency order was: H 4 -EDTA > Na 2 EDTA > (NH 4 ) 2 EDTA. At low EDTA concentrations the removal increased progressively with increasing dose while above 0.4 mmol/g only small increases in extraction efficiency were observed. EDTA induced a two-step process including a rapid desorption within the first hour, and a gradual release in the following hours. The extraction efficiency of metals decreased with increasing pH in the range of 2-10. Consecutive extractions using low concentrations were more effective than a single extraction with concentrated EDTA if the same dose of EDTA was used. - Consecutive extractions using low concentrations are more effective than a single extraction with concentrated EDTA if the same dose of EDTA is used

  17. Multifunctional adhesive polymers: Preactivated thiolated chitosan-EDTA conjugates.

    Science.gov (United States)

    Netsomboon, Kesinee; Suchaoin, Wongsakorn; Laffleur, Flavia; Prüfert, Felix; Bernkop-Schnürch, Andreas

    2017-02-01

    The aim of this study was to synthesis preactivated thiolated chitosan-EDTA (Ch-EDTA-cys-2MNA) conjugates exhibiting in particular high mucoadhesive, cohesive and chelating properties. Thiol groups were coupled with chitosan by carbodiimide reaction and further preactivated by attachment with 2-mercaptonicotinic acid (2MNA) via disulfide bond formation. Determinations of primary amino and sulfhydryl groups were performed by TNBS and Ellman's tests, respectively. Cytotoxicity was screened by resazurin assay in Caco-2 cells. Mucoadhesive properties and bivalent cation binding capacity with Mg 2+ and Ca 2+ in comparison to chitosan-EDTA (Ch-EDTA) and thiolated Ch-EDTA (Ch-EDTA-cys) were evaluated. Determination of 2MNA and total sulfhydryl groups indicated that 80% of thiol groups were preactivated. The results from cytotoxicity studies demonstrated that Ch-EDTA-cys and Ch-EDTA-cys-2MNA were not toxic to the cells at the polymer test concentration of 0.25% (w/v) while cell viability decreased by increasing the concentration of Ch-EDTA. Although EDTA molecule was modified by thiolation and preactivation, approximately 50% of chelating properties of the conjugates were maintained compared to Ch-EDTA. Ch-EDTA-cys-2MNA adhered on freshly excised porcine intestinal mucosa up to 6h while Ch-EDTA adhered for just 1h. According to the combination of mucoadhesive and chelating properties of the conjugates synthesized in this study, Ch-EDTA-cys-2MNA might be useful for various mucosal drug delivery systems. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Anaerobic Biotransformation and Mobility of Pu and Pu-EDTA

    International Nuclear Information System (INIS)

    Bolton, H. Jr.; Rai, D.; Xun, L.

    2005-01-01

    The complexation of radionuclides (e.g., plutonium (Pu) and 60 Co) by codisposed ethylenediaminetetraacetate (EDTA) has enhanced their transport in sediments at DOE sites. Our previous NABIR research investigated the aerobic biodegradation and biogeochemistry of Pu(IV)-EDTA. Plutonium(IV) forms stable complexes with EDTA under aerobic conditions and an aerobic EDTA degrading bacterium can degrade EDTA in the presence of Pu and decrease Pu mobility. However, our recent studies indicate that while Pu(IV)-EDTA is stable in simple aqueous systems, it is not stable in the presence of relatively soluble Fe(III) compounds (i.e., Fe(OH) 3 (s)--2-line ferrihydrite). Since most DOE sites have Fe(III) containing sediments, Pu(IV) in likely not the mobile form of Pu-EDTA in groundwater. The only other Pu-EDTA complex stable in groundwater relevant to DOE sites would be Pu(III)-EDTA, which only forms under anaerobic conditions. Research is therefore needed in this brand new project to investigate the biotransformation of Pu and Pu-EDTA under anaerobic conditions. The biotransformation of Pu and Pu-EDTA under various anaerobic regimes is poorly understood including the reduction kinetics of Pu(IV) to Pu(III) from soluble (Pu(IV)-EDTA) and insoluble Pu(IV) as PuO2(am) by metal reducing bacteria, the redox conditions required for this reduction, the strength of the Pu(III)-EDTA complex, how the Pu(III)-EDTA complex competes with other dominant anoxic soluble metals (e.g., Fe(II)), and the oxidation kinetics of Pu(III)-EDTA. Finally, the formation of a stable soluble Pu(III)-EDTA complex under anaerobic conditions would require degradation of the EDTA complex to limit Pu(III) transport in geologic environments. Anaerobic EDTA degrading microorganisms have not been isolated. These knowledge gaps preclude the development of a mechanistic understanding of how anaerobic conditions will influence Pu and Pu-EDTA fate and transport to assess, model, and design approaches to stop Pu

  19. Characterisation of citrate and iron citrate uptake by cultured rat hepatocytes

    International Nuclear Information System (INIS)

    Graham, R.M.; Morgan, E.H.; Baker, E.

    1998-01-01

    Background/Aims: the endogenous low molecular weight iron chelator, citrate, is considered to be an important contributor to iron transport and the liver the main site of uptake of iron citrate in subjects suffering from diseases of iron overload. Moreover, the citrate-metabolising enzyme, aconitase, is implicated in the regulation of cellular iron metabolism. This study was undertaken to determine the role of citrate and ferric citrate in the uptake of iron by rat hepatocytes. Methods: Cultured rat hepatocytes were incubated (37 deg. C, 15 min) with 100 μM [ 14 C]-citrate in the presence or absence of 1.0 μM 55 Fe. Membrane-bound and intracellular radiolabel were separated by incubation with the general protease, Pronase. Results: Our results suggest that ferric citrate uptake is mediated by a specific citrate binding site which exhibits a higher affinity for citrate in the presence of iron than in its absence. Citrate was internalised by hepatocytes, with at least 70% being oxidised to CO 2 within 15 min. Citrate uptake was pH-dependent, did not require the presence of sodium and increased with increasing iron concentration. Metabolic energy, anion channels, the Na + , K + -ATPase and vesicle acidification do not appear to play a role in uptake of ferric citrate, but functional sulphydryl groups may be involved. Conclusions: The data suggest either that ferric citrate complexes with higher molar ratios of iron to citrate relative to the incubation medium are bound preferentially to the membrane, or that once citrate has delivered its iron to the membrane, the complex dissociates and the components are internalised separately. (au)

  20. Buffer Zone Fact Sheets

    Science.gov (United States)

    New requirements for buffer zones and sign posting contribute to soil fumigant mitigation and protection for workers and bystanders. The buffer provides distance between the pesticide application site and bystanders, reducing exposure risk.

  1. Aluminum elution and precipitation in glass vials: effect of pH and buffer species.

    Science.gov (United States)

    Ogawa, Toru; Miyajima, Makoto; Wakiyama, Naoki; Terada, Katsuhide

    2015-02-01

    Inorganic extractables from glass vials may cause particle formation in the drug solution. In this study, the ability of eluting Al ion from borosilicate glass vials, and tendencies of precipitation containing Al were investigated using various pHs of phosphate, citrate, acetate and histidine buffer. Through heating, all of the buffers showed that Si and Al were eluted from glass vials in ratios almost the same as the composition of borosilicate glass, and the amounts of Al and Si from various buffer solutions at pH 7 were in the following order: citrate > phosphate > acetate > histidine. In addition, during storage after heating, the Al concentration at certain pHs of phosphate and acetate buffer solution decreased, suggesting the formation of particles containing Al. In citrate buffer, Al did not decrease in spite of the high elution amount. Considering that the solubility profile of aluminum oxide and the Al eluting profile of borosilicate glass were different, it is speculated that Al ion may be forced to leach into the buffer solution according to Si elution on the surface of glass vials. When Al ions were added to the buffer solutions, phosphate, acetate and histidine buffer showed a decrease of Al concentration during storage at a neutral range of pHs, indicating the formation of particles containing Al. In conclusion, it is suggested that phosphate buffer solution has higher possibility of forming particles containing Al than other buffer solutions.

  2. Artificial Citrate Operon Confers Mineral Phosphate Solubilization Ability to Diverse Fluorescent Pseudomonads

    Science.gov (United States)

    Adhikary, Hemanta; Sanghavi, Paulomi B.; Macwan, Silviya R.; Archana, Gattupalli; Naresh Kumar, G.

    2014-01-01

    Citric acid is a strong acid with good cation chelating ability and can be very efficient in solubilizing mineral phosphates. Only a few phosphate solubilizing bacteria and fungi are known to secrete citric acids. In this work, we incorporated artificial citrate operon containing NADH insensitive citrate synthase (gltA1) and citrate transporter (citC) genes into the genome of six-plant growth promoting P. fluorescens strains viz., PfO-1, Pf5, CHAO1, P109, ATCC13525 and Fp315 using MiniTn7 transposon gene delivery system. Comprehensive biochemical characterization of the genomic integrants and their comparison with plasmid transformants of the same operon in M9 minimal medium reveals the highest amount of ∼7.6±0.41 mM citric and 29.95±2.8 mM gluconic acid secretion along with ∼43.2±3.24 mM intracellular citrate without affecting the growth of these P. fluorescens strains. All genomic integrants showed enhanced citric and gluconic acid secretion on Tris-Cl rock phosphate (TRP) buffered medium, which was sufficient to release 200–1000 µM Pi in TRP medium. This study demonstrates that MPS ability could be achieved in natural fluorescent pseudomonads by incorporation of artificial citrate operon not only as plasmid but also by genomic integration. PMID:25259527

  3. Biodegradation of PuEDTA and Impacts on Pu Mobility

    International Nuclear Information System (INIS)

    Xun, Luying; Bolton, Jr. Harvey

    2002-01-01

    This project, by Dr. Xun, supports work at PNNL (Bolton) regarding plutonium mobility in the subsurface. Ethylenediaminetetraacetate (EDTA) is a chelating agent that can increase the mobility of radionuclides and heavy metals in groundwater. Biodegradation of EDTA can decrease the enhanced mobility. The overall objective is to understand how microbial degradation affects Plutonium-EDTA transport in the environment and the specific objective of this component is to understand how microorganisms degrade EDTA. A chelating degrading bacterium BNC1 can use EDTA and nitrilotriacetate (NTA) as sole carbon and nitrogen sources. A gene cluster responsible for both EDTA and NTA degradation has been cloned and characterized (1,2). The same enzymes are used to degrade both compounds except that additional enzymes are required for EDTA degradation. Since the enzymes are located inside cells, EDTA and NTA must be transported into cells for degradation. For the first funding year, we have focused on how EDTA and NTA are transported into BNC1 cells. The EDTA-degrading gene cluster also contains genes encoding a hypothetical ABC-type transporter. We first demonstrated that the transporter genes and EDTA monooxygenase gene (emoA) were co-transcribed by RT-PCR, suggesting that the genes are involved in EDTA transport. We then characterized one of the gene product EppA. Using recombinant EppA purified from Escherichia coli, we have shown that EppA binds several metal:EDTA complexes by fluorescence techniques. In addition, EppA is shown to bind Mg:NTA, Ca:NTA and Fe(III):NTA but not free NTA

  4. Incompatibility of Contrast Medium and Trisodium Citrate

    International Nuclear Information System (INIS)

    Delcour, Christian; Bruninx, Guy

    2013-01-01

    To test the compatibility of trisodium citrate, a catheter lock solution, with iodinated contrast medium. Iohexol, iobitridol, iodixanol, ioxaglate, ioxithalamate, iomeprol, and iopromide were tested. In all tests, 2 ml of contrast medium were mixed with 2 ml of trisodium citrate solution. Iodixanol and ioxaglate provoked a highly viscous gluelike precipitation when mixed with trisodium citrate. A brief transient precipitate was observed with iohexol, iomeprol, and ioxithalamate. Permanent precipitation occurred with iobitridol and iopromide. One must be aware of the potential for precipitation when contrast medium is mixed with trisodium citrate solution. Before trisodium citrate solution is injected, the catheter should be thoroughly flushed with saline if a contrast medium has previously been injected through it.

  5. Similarity of salt influences on the pH of buffers, polyelectrolytes, and proteins.

    Science.gov (United States)

    Voinescu, Alina E; Bauduin, Pierre; Pinna, M Cristina; Touraud, Didier; Ninham, Barry W; Kunz, Werner

    2006-05-04

    Changes in pH induced by the addition of electrolytes to buffers, polyelectrolytes (a polycarboxy polymethylene and a polyethyleneimine), and proteins (casein, whey, and lysozyme) solutions are explored systematically. The two buffer systems are triethanolamine/triethanolammonium chloride and citric acid/sodium citrate. These are chosen because of the similarity of their acid-base equilibria with those of amino acids predominant in most proteins, that is, amino acids that include carboxylate or ammonium groups in their structures. The pH of triethanolamine and of citrate buffers respectively increases and decreases when salt is added. At low electrolyte concentrations (buffer solutions. It is even possible to qualitatively predict these changes in protein solutions simply from the primary protein structure. At least in the systems considered here, the specific ion effects on pH seem to correlate with the bulk activity coefficients of the added electrolytes, at least at moderate salt concentrations.

  6. Biological degradation of EDTA in pulping effluents at higher pH - a laboratory study

    Energy Technology Data Exchange (ETDEWEB)

    Ek, M; Remberger, M; Allard, A S

    1999-01-01

    The biological degradation of EDTA at different pH, sludge load and sludge age has been investigated in laboratory experiments. The experiments showed that relatively fast degradation of EDTA in the form found in this waste water (from production of TMP) took place at least at pH around 8.5 with moderate COD load and high sludge age. In continuous reactors the degradation of EDTA in a pulp and paper waste water was 2-3 mg EDTA/g SS*day at both pH 7 and 8,5, and at sludge ages from 5 to 21 days. The degradation was dependent on sludge load, and no degradation was seen above 1 g COD/g SS*day. In kinetic experiments with half strength waste water the same degradation rate (1,5-2 mg EDTA/g SS*day) was found at pH 7 and at pH 8,5 with sludge of low age (9 and 5 days SRT). Much faster degradation was found at pH 8,5 with sludge of high age (21 days in the continuous experiment). The mean degradation rate was over 10 mg EDTA/g SS*day from 20 to 5 mg EDTA/l. v{sub max} was determined to be 35 mg EDTA/g SS*day and K{sub M} to 31 mg EDTA/l. COD removal was at least as good at pH 8,5 as at pH 7. Sludge properties were best at pH 8,5 and long sludge retention time (giving low sludge load). Both sludge volume index and residual suspended solids after sedimentation were lower than under normal conditions at pH 7. The direct cost for caustic lime would be about 15 SEK per ton of TMP, with a water like the one investigated here. This can vary a lot depending on starting pH and buffering capacity. Costs for addition of nitrogen source could probably be omitted, but this is normally not more than 1-2 SEK per ton of TMP. The extra need for oxygen in the treatment would not be more than some percent, but may be important if oxygen is limited. A substantial extra cost would be if the aeration volume has to be increased. According to the best results from the kinetic study, this would not be needed in an extended aeration activated plant with 2 days HRT and sludge concentrations of 2

  7. Redox Buffer Strength

    Science.gov (United States)

    de Levie, Robert

    1999-04-01

    The proper functioning of enzymes in bodily fluids requires that the pH be maintained within rather narrow limits. The first line of defense against large pH fluctuations in such fluids is the passive control provided by the presence of pH buffers. The ability of pH buffers to stabilize the pH is indicated by the buffer value b introduced in 1922 by van Slyke. It is equally important for many enzymes that the redox potential is kept within a narrow range. In that case, stability of the potential is most readily achieved with a redox buffer. In this communication we define the redox buffer strength by analogy with acid-base buffer strength.

  8. Optimalization of Poly(neutral red Coated-wire Electrode for Determination of Citrate in Soft Drinks

    Directory of Open Access Journals (Sweden)

    Vladimír Král

    2008-02-01

    Full Text Available This report presents an optimization of potentiometric measurements withcitrate-selective electropolymerized poly(neutral red electrodes. The optimal backgroundelectrolyte for these measurements is a TRIS buffer with nitrate at pH 8.5. The electrodesdescribed here exhibit stable and reproducible near-Nernstian response to citrates with alow detection limit of 6 × 10-6 M. Electrodes polymerized from sulfuric acid andacetonitrile are compared in detail. Simple and sensitive method for quantification ofcitrate in real-life samples by potentiometry with poly(neutral red electrodes arepresented. Data from potentiometric measurements of citrate are compared with capillaryelectrophoresis.

  9. 21 CFR 522.800 - Droperidol and fentanyl citrate injection.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Droperidol and fentanyl citrate injection. 522.800... § 522.800 Droperidol and fentanyl citrate injection. (a) Specifications. Droperidol and fentanyl citrate injection is a sterile solution containing 20 milligrams of droperidol and 0.4 milligram of fentanyl citrate...

  10. Outer Sphere Adsorption of Pb(II)EDTA on Goethite

    Energy Technology Data Exchange (ETDEWEB)

    Bargar, John R

    1999-07-16

    FTIR and EXAFS spectroscopic measurements were performed on Pb(II)EDTA adsorbed on goethite as functions of pH (4-6), Pb(II)EDTA concentration (0.11 {micro}M - 72 {micro}M), and ionic strength (16 {micro}M - 0.5M). FTIR measurements show no evidence for carboxylate-Fe(III) bonding or protonation of EDTA at Pb:EDTA = 1:1. Both FTIR and EXAFS measurements suggest that EDTA acts as a hexadentate ligand, with all four of its carboxylate and both amine groups bonded to Pb(II). No evidence was observed for inner-sphere Pb(II)-goethite bonding at Pb:EDTA = 1:1. Hence, the adsorbed complexes should have composition Pb(II)EDTA{sup 2{minus}}. Since substantial uptake of PbEDTA(II){sup 2{minus}} occurred in the samples, we infer that Pb(II)EDTA{sup 2{minus}} adsorbed as outer-sphere complexes and/or as complexes that lose part of their solvation shells and hydrogen bond directly to goethite surface sites. We propose the term ''hydration-sphere'' for the latter type of complexes because they should occupy space in the primary hydration spheres of goethite surface functional groups, and to distinguish this mode of sorption from common structural definitions of inner- and outer-sphere complexes. The similarity of Pb(II) uptake isotherms to those of other divalent metal ions complexed by EDTA suggests that they too adsorb by these mechanisms. The lack of evidence for inner-sphere EDTA-Fe(III) bonding suggests that previously proposed metal-ligand - promoted dissolution mechanisms should be modified, specifically to account for the presence of outer-sphere precursor species.

  11. Protective effect of EDTA preadministration on renal ischemia

    Directory of Open Access Journals (Sweden)

    Belloni Daniela

    2006-03-01

    Full Text Available Abstract Background Chelation therapy with sodium edetate (EDTA improved renal function and slowed the progression of renal insufficiency in patients subjected to lead intoxication. This study was performed to identify the underlying mechanism of the ability of EDTA treatment to protect kidneys from damage. Methods The effects of EDTA administration were studied in a rat model of acute renal failure induced by 60 minutes ischemia followed or not by 60 minutes reperfusion. Renal ischemic damage was evaluated by histological studies and by functional studies, namely serum creatinine and blood urea nitrogen levels. Treatment with EDTA was performed 30 minutes before the induction of ischemia. Polymorphonuclear cell (PMN adhesion capability, plasmatic nitric oxide (NO levels and endothelial NO synthase (eNOS renal expression were studied as well as the EDTA protection from the TNFα-induced vascular leakage in the kidneys. Data was compared by two-way analysis of variance followed by a post hoc test. Results EDTA administration resulted in the preservation of both functional and histological parameters of rat kidneys. PMN obtained from peripheral blood of EDTA-treated ischemized rats, displayed a significant reduction in the expression of the adhesion molecule Mac-1 with respect to controls. NO was significantly increased by EDTA administration and eNOS expression was higher and more diffuse in kidneys of rats treated with EDTA than in the controls. Finally, EDTA administration was able to prevent in vivo the TNFα-induced vascular leakage in the kidneys. Conclusion This data provides evidence that EDTA treatment is able to protect rat kidneys from ischemic damage possibly through the stimulation of NO production.

  12. Organellar Calcium Buffers

    Science.gov (United States)

    Prins, Daniel; Michalak, Marek

    2011-01-01

    Ca2+ is an important intracellular messenger affecting many diverse processes. In eukaryotic cells, Ca2+ storage is achieved within specific intracellular organelles, especially the endoplasmic/sarcoplasmic reticulum, in which Ca2+ is buffered by specific proteins known as Ca2+ buffers. Ca2+ buffers are a diverse group of proteins, varying in their affinities and capacities for Ca2+, but they typically also carry out other functions within the cell. The wide range of organelles containing Ca2+ and the evidence supporting cross-talk between these organelles suggest the existence of a dynamic network of organellar Ca2+ signaling, mediated by a variety of organellar Ca2+ buffers. PMID:21421925

  13. Studies on sildenafil citrate (Viagra) interaction with DNA using electrochemical DNA biosensor.

    Science.gov (United States)

    Rauf, Sakandar; Nawaz, Haq; Akhtar, Kalsoom; Ghauri, Muhammad A; Khalid, Ahmad M

    2007-05-15

    The interaction of sildenafil citrate (Viagra) with DNA was studied by using an electrochemical DNA biosensor. The binding mechanism of sildenafil citrate was elucidated by using constant current potentiometry and differential pulse voltammetry at DNA-modified glassy carbon electrode. The decrease in the guanine oxidation peak area or peak current was used as an indicator for the interaction in 0.2M acetate buffer (pH 5). The binding constant (K) values obtained were 2.01+/-0.05 x 10(5) and 1.97+/-0.01 x 10(5)M(-1) with constant current potentiometry and differential pulse voltammetry, respectively. A linear dependence of the guanine peak area or peak current was observed within the range of 1-40 microM sildenafil citrate with slope=-2.74 x 10(-4)s/microM, r=0.989 and slope=-2.78 x 10(-3)microA/microM, r=0.995 by using constant current potentiometry and differential pulse voltammetry, respectively. Additionally, binding constant values for sildenafil citrate-DNA interaction were determined for the pH range of 4-8 and in biological fluids (serum and urine) at pH 5. The influence of sodium and calcium ions was also studied to elucidate the mechanism of sildenafil citrate-DNA interaction under different solution conditions. The present study may prove to be helpful in extending our understanding of the anticancer activity of sildenafil citrate from cellular to DNA level.

  14. nanoparticles synthesized by citrate precursor m

    African Journals Online (AJOL)

    user

    (M=Co, Cu) nanoparticles synthesized by citrate precursor method ... The structural characterization was carried out using an X-ray Diffractometer (Rikagu Miniflex, Japan) ..... His current area of interest includes magnetic nanomaterials.

  15. Inducible transport of citrate in Lactobacillus rhamnosus ATCC 7469.

    Science.gov (United States)

    de Figueroa, R M; Benito de Cárdenas, I L; Sesma, F; Alvarez, F; de Ruiz Holgado, A P; Oliver, G

    1996-10-01

    Lactobacillus rhamnosus ATCC 7469 exhibited diauxie when grown in a medium containing both glucose and citrate as energy source. Glucose was used as the primary energy source during the glucose-citrate diauxie. Uptake of citrate was carried out by an inducible citrate transport system. The induction of citrate uptake system was repressed in the presence of glucose. This repression was reversible and mediated by cAMP.

  16. Ligand-enhanced electrokinetic remediation of metal-contaminated marine sediments with high acid buffering capacity.

    Science.gov (United States)

    Masi, Matteo; Iannelli, Renato; Losito, Gabriella

    2016-06-01

    The suitability of electrokinetic remediation for removing heavy metals from dredged marine sediments with high acid buffering capacity was investigated. Laboratory-scale electrokinetic remediation experiments were carried out by applying two different voltage gradients to the sediment (0.5 and 0.8 V/cm) while circulating water or two different chelating agents at the electrode compartments. Tap water, 0.1 M citric acid and 0.1 M ethylenediaminetetraacetic acid (EDTA) solutions were used respectively. The investigated metals were Zn, Pb, V, Ni and Cu. In the unenhanced experiment, the acid front could not propagate due to the high acid buffering capacity of the sediments; the production of OH(-) ions at the cathode resulted in a high-pH environment causing the precipitation of CaCO3 and metal hydroxides. The use of citric acid prevented the formation of precipitates, but solubilisation and mobilisation of metal species were not sufficiently achieved. Metal removal was relevant when EDTA was used as the conditioning agent, and the electric potential was raised up to 0.8 V/cm. EDTA led to the formation of negatively charged complexes with metals which migrated towards the anode compartment by electromigration. This result shows that metal removal from sediments with high acid buffering capacity may be achieved by enhancing the electrokinetic process by EDTA addition when the acidification of the medium is not economically and/or environmentally sustainable.

  17. EDTA modified glassy carbon electrode: Preparation and characterization

    International Nuclear Information System (INIS)

    Ustuendag, Zafer; Solak, Ali Osman

    2009-01-01

    EDTA-phenoxyamide modified glassy carbon electrode (EDTA-GC) was prepared at a glassy carbon electrode by surface synthesis. In the first step, nitrophenyl was grafted to the glassy carbon (GC) surface via the electrochemical reduction of its tetraflouroborate diazonium salt. In the second step, nitrophenyl-modified electrode (NP-GC) was subjected to the cathodic potential scan to reduce the nitro to amine group. p-Aminophenyl modified glassy carbon electrode (AP-GC) was dipped into a EDTA solution containing 1-ethyl-3(3-(dimethlyamino)propyl)-carbodiimide (EDC) as an activating agent. Thus formed ((2-anilino-2-oxoethyl){2-[bis(carboxymethyl)amino]-ethyl}amino)acetic acid modified GC electrode was denoted as EDTA-GC and characterized by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), ellipsometry and X-ray photoelectron spectroscopy (XPS). Complexation of the EDTA-GC surface with Pb 2+ ions was investigated if this electrode could be used as a metal sensor.

  18. Coulometric titration of niobium in EDTA complexing solution

    International Nuclear Information System (INIS)

    Pannu, S.S.

    1976-01-01

    Constant current coulometry of Nb in EDTA was studied employing both potentiometric and amperometric end-point techniques. The titrations were based on the oxidation of Nb(IV)-EDTA with electrogenerated Fe(III) at a graphite anode. The rate of disproportionation of Nb(IV)-EDTA was found to be slow enough not to effect the accuracy sought for the titration. The coulometric titration of Nb in EDTA was found to be more accurate than in 1F sulfuric acid. The mean error in the titrations of 4.76 to 19.65 of Nb in a volume of about 100 ml of 0.02 to 0.04F EDTA was 0.13%. It was found that Ta may be tolerated to a ratio of 1:4, Ta:Nb, in a solution containing 13 mg of Nb. (author)

  19. Growth and characterization of EDTA assisted CBD-CdS

    Energy Technology Data Exchange (ETDEWEB)

    Kumarage, W.G.C.; Wijesundera, R. P.; Seneviratne, V. A.; Jayalath, C. P.; Varga, Tamas; Nandasiri, Manjula I.; Dassanayake, B. S.

    2017-10-01

    Chemical bath deposition of CdS (CBD-CdS) thin films with the assistance of a cationic surfactant, ethylenediamine tetraacetic acid (EDTA), is reported in this work. Also the EDTA treated CdS thin films are compared with that of conventional CBD-CdS. Fabricated thin, compact, uniform and adherent EDTA treated CdS films show enhanced effective surface area and roughness compared to conventional CBD-CdS. The grazing incidence x-ray diffraction analysis shows all the fabricated CdS films are hexagonally crystallized. EDTA-treated CdS films show excellent photo activity compared to conventional CBDCdS. The flat band potential (Vfb) value was found to be tunable with EDTA concentration.

  20. The ERA-EDTA today and tomorrow: a progress document by the ERA-EDTA Council.

    Science.gov (United States)

    Zoccali, Carmine; Arici, Mustafa; Blankestijn, Peter J; Bruchfeld, Annette; Capasso, Giovambattista; Fliser, Danilo; Fouque, Denis; Goumenos, Dimitrios; Ketteler, Markus; Malyszko, Jolanta; Massy, Ziad; Rychlík, Ivan; Spasovski, Goce

    2018-05-23

    Scientific societies are increasingly seen as central to the advancement of information sharing and collaboration among scientists and clinical investigators for the progress of medical research and the promotion of education, professional competence, integrity and quality studies. To more effectively serve the practicing nephrologists and investigators dedicated to renal science, the Council of the European Renal Association and European Dialysis and Transplantation Association (ERA-EDTA) reorganized and integrated the various activities of the society into two branches, the Clinical Nephrology Governance branch and the Renal Science branch. New affordable initiatives to promote research, education and professional development and to advocate for the recognition of chronic kidney disease as a major public health issue at the European level will be put in place and/or potentiated in the new organizational frame. Educational initiatives will be espoused to Continuous Professional Development and, starting from 2019, 14 Education & Continuous Professional Development courses will be held covering the full range of knowledge areas of modern nephrology. Consolidation and development is the short- and medium-term mantra of the ERA-EDTA. The society has a rich portfolio of successful activities and brilliant, creative scientists among its members. Integrating the various activities of the ERA-EDTA and treasuring the expertise and wisdom of its most accomplished members will facilitate collaborative research, education and its public impact at large.

  1. Effects of calcium binding and of EDTA and CaEDTA on the clotting of bovine fibrinogen by thrombin.

    Science.gov (United States)

    Perizzolo, K E; Sullivan, S; Waugh, D F

    1985-03-01

    Studies were carried out at pH 7.0 and gamma/2 0.15 before addition of CaCl2 or EDTA. Clotting time, tau, at 3.03 microM fibrinogen and 0.91 u/ml thrombin was determined for equilibrium systems. With added Ca2+, tau decreases, from tau 0 at 0 added Ca2+ (mean, 29.7 +/- 3 s), by approximately 3 s at 5 mM added Ca2+. With added EDTA, tau increases sigmoidally from tau 0 at 0 EDTA to a maximum (mean tau m = 142 +/- 23 s) at approximately 200 microM EDTA. tau then decreases slightly to a minimum at approximately 1.3 mM and finally increases to infinity at approximately 10 mM EDTA. Between 0 and 1.3 mM EDTA, effects on clotting time are completely reversed by adding Ca2+ and, after equilibration at 400 microM EDTA, tau is independent of EDTA concentration. Thus, up to 400 microM EDTA, effects on clotting time are attributed to decreasing fibrinogen bound Ca2+. Between 5 mM Ca2+ and 200 microM EDTA it is assumed that an equilibrium distribution of fibrinogen species having 3, 2, 1, or 0 bound calcium ions is established and that a clotting time is determined by the sum of products of species fractional abundance and pure species clotting time. Analysis indicates that pure species clotting times increase proportionately with decreasing Ca2+ binding, binding sites are nearly independent, and the microscopic association constant for the first bound Ca2+ is approximately 4.9 X 10(6) M-1. Effects of adding Ca2+ at times t1 after thrombin addition to systems initially equilibrated at 200 microM EDTA were determined. Analysis of the relation between tau and t1 indicates that as Ca2+ binding decreases, rate constants for release of B peptides decrease less than those for release of A peptides. As EDTA concentration is increased above 1.3 mM, inhibitory effects of EDTA and CaEDTA progressively increase.

  2. Agarose electrophoresis of DNA in discontinuous buffers, using a horizontal slab apparatus and a buffer system with improved properties.

    Science.gov (United States)

    Zsolnai, A; Orbán, L; Chrambach, A

    1993-03-01

    Using a horizontal slab apparatus with a buffer in the reservoirs at the level of the gel ("sea-level electrophoresis"), the retrograde discontinuous buffer system reported by Wiltfang et al. for sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) of proteins was applied to DNA electrophoresis. This application yielded the advantages of an increased displacement rate of the moving boundary front and a decrease in the concentration of the counterion base in the resolving phase, which yielded reduced relative mobility values at equivalent gel concentrations and practicable low buffer concentrations. The change of relative mobilities (Rf) with a variation of field strength is decreased compared to that of the migration rate in the continuous Tris-boric-acid-EDTA (TBE) buffer and thus the robustness of the system is improved, as well as the efficiency of separation. The system of Wiltfang et al. has in common with previously described discontinuous DNA system, that it is able to stack DNA from dilute samples and is insensitive to sample components with lower net mobilities than DNA, such as acetate. However, the variance of Rf at constant current density in the discontinuous buffer system is not improved over that of the migration rate at constant field strength in the continuous TBE buffer.

  3. Modification of gel architecture and TBE/TAE buffer composition to minimize heating during agarose gel electrophoresis.

    Science.gov (United States)

    Sanderson, Brian A; Araki, Naoko; Lilley, Jennifer L; Guerrero, Gilberto; Lewis, L Kevin

    2014-06-01

    Agarose gel electrophoresis of DNA and RNA is routinely performed using buffers containing either Tris, acetate, and EDTA (TAE) or Tris, borate, and EDTA (TBE). Gels are run at a low, constant voltage (∼10 V/cm) to minimize current and asymmetric heating effects, which can induce band artifacts and poor resolution. In this study, alterations of gel structure and conductive media composition were analyzed to identify factors causing higher electrical currents during horizontal slab gel electrophoresis. Current was reduced when thinner gels and smaller chamber buffer volumes were used, but was not influenced by agarose concentration or the presence of ethidium bromide. Current was strongly dependent on the amount and type of EDTA used and on the concentrations of the major acid-base components of each buffer. Interestingly, resolution and the mobilities of circular versus linear plasmid DNAs were also affected by the chemical form and amount of EDTA. With appropriate modifications to gel structure and buffer constituents, electrophoresis could be performed at high voltages (20-25 V/cm), reducing run times by up to 3-fold. The most striking improvements were observed with small DNAs and RNAs (10-100 bp): high voltages and short run times produced sharper bands and higher resolution. Copyright © 2014 Elsevier Inc. All rights reserved.

  4. The importance of adding EDTA for the nanopore analysis of proteins.

    Science.gov (United States)

    Krasniqi, Besnik; Lee, Jeremy S

    2012-06-01

    Nanopore analysis is a promising technique for studying the conformation of proteins and protein/protein interactions. Two proteins (bacterial thioredoxin and maltose binding protein) were subjected to nanopore analysis with α-hemolysin. Two types of events were observed; bumping events with a blockade current less than -40 pA and intercalation events with blockade currents between -40 pA and -100 pA. In potassium phosphate buffer, pH 7.8, both proteins gave intercalation events but the frequency of these events was significantly reduced in TRIS or HEPES buffers especially in the presence of 0.01 mM divalent metal ions. The frequency of events was restored by the addition of EDTA. For maltose binding protein, the frequency of intercalation events was also decreased in the presence of maltose but not lactose to which it does not bind. It is proposed that the events with large blockade currents represent transient intercalation of a loop or end of the protein into the pore and that divalent metal ions inhibit this process. The results demonstrate that the choice of buffer and the effects of metal ion contamination are important considerations in nanopore analysis.

  5. The kinetics of lanthanide complexation by EDTA and DTPA in lactate media.

    Science.gov (United States)

    Nash, K L; Brigham, D; Shehee, T C; Martin, A

    2012-12-28

    The interaction of trivalent lanthanide and actinide cations with polyaminopolycarboxylic acid complexing agents in lactic acid buffer systems is an important feature of the chemistry of the TALSPEAK process for the separation of trivalent actinides from lanthanides. To improve understanding of metal ion coordination chemistry in this process, the results of an investigation of the kinetics of lanthanide complexation by ethylenediamine-N,N,N',N'-tetraacetic acid (EDTA) and diethylenetriamine-N,N,N',N'',N''-pentaacetic acid (DTPA) in 0.3 M lactic acid/0.3 M ionic strength solution are reported. Progress of the reaction was monitored using the distinctive visible spectral changes attendant to lanthanide complexation by the colorimetric indicator ligand Arsenazo III, which enables the experiment but plays no mechanistic role. Under the conditions of these experiments, the reactions occur in a time regime suitable for study by stopped-flow spectrophotometric techniques. Experiments have been conducted as a function of EDTA/DTPA ligand concentration, total lactic acid concentration, and pH. The equilibrium perturbation reaction proceeds as a first order approach to equilibrium over a wide range of conditions, allowing the simultaneous determination of complex formation and dissociation rate constants. The rate of the complexation reaction has been determined for the entire lanthanide series (except Pm(3+)). The predominant pathway for lanthanide-EDTA and lanthanide-DTPA dissociation is inversely dependent on the total lactate concentration; the complex formation reaction demonstrates a direct dependence on [H(+)]. Unexpectedly, the rate of the complex formation reaction is seen in both ligand systems to be fastest for Gd(3+). Correlation of these results indicates that in 0.3 M lactate solutions the exchange of lanthanide ions between lactate complexes and the polyaminopolycarboxylate govern the process.

  6. Direct separation of 67Ga citrate from zinc and copper target materials by an ion exchange

    International Nuclear Information System (INIS)

    El-Azony, K.M.; Ferieg, Kh.; Saleh, Z.A.

    2004-01-01

    The separation of 6 7G a from zinc and copper target materials using an anion- f:exchanger (Dowex21K) and 0.1 M citrate buffer at pH 6 is described. The gallium-67 was separated in citrate solution and can be directly used for medical applications. Gallium-67 with a half-life of 78.3 h and gamma-rays with energies of 93, 185 and 300 keV is a cyclotron produced radioisotope for which a considerable demand exists. 6 7G a is frequently produced through proton or deuteron bombardment of natural or enriched Zn targets (Helus and Maier-Borst, 1973). It is usually separated from Zn by ion exchange chromatography (Helus and Maier-Borst, 1973; van der Walt and Strelow, 1983) or by liquid extraction Helus and Maier-Borst, 1973; Hupf and Beaver, 1970). The isotope is usually supplied in citrate solution which is widely used as 6 7G a Gallium citrate which is a well-established radiopharmaceutical for imaging soft tissue tumors and abscesses. Several routes for large scale production of 6 7G a and the development of medical applications have been reported (Silvester and Thakur, 1970; Dahl and Tilbury, 1972; Steyn and Meyer,1973; Vlatkovic et al., 1975; Neirinckx, 1976; Thakur, 1977). Various attempts were carried out to separate gallium-67 by using different ion exchange methods (Strelow et al., 1971; Das and Ramamoorthy, 1995; Boothe et al.,1991) through the labelling of citrate by using 6 7G a was carried out for medical applications

  7. Citrate and succinate uptake by potato mitochondria

    International Nuclear Information System (INIS)

    Jung, D.W.; Laties, G.G.

    1979-01-01

    Potato mitochondria, in the absence of respiration, have a very low capacity for uptake by exchange with endogenous anions, taking up only 2.4 nanomoles citrate and 2.0 nanomoles succinate per milligram protein. Maximum citrate uptake of over 17 nanomoles per milligram protein occurs in the presence of inorganic phosphate, a dicarboxylic acid, and an external energy source (NADH), conditions where net anion accumulation proceeds, mediated by the interlinking of the inorganic phosphate, dicarboxylate, and tricarboxylate carriers. Maximum succinate uptake in the absence of respiratory inhibitors requires only added inorganic phosphate. Compounds which inhibit respiration (antimycin), the exchange carriers (mersalyl and benzylmalonate), or the establishment of the membrane proton motive force (uncouplers) reduce substrate accumulation. A potent inhibitor of the citrate carrier in animal mitochondria, 1,2,3-benzenetricarboxylic acid, does not inhibit citrate uptake in potato mitochondria. Citrate uptake is reduced by concurrent ADP phosphorylation and this reduction is sensitive to oligomycin. The initiation of state 3 after a 3-minute substrate state results in a reduction of the steady-state of citrate uptake by approximately 50%. Accumulation of succinate initially is inhibited by increasing sucrose concentration in the reaction medium from 50 to 400 millimolar. Limited substrate uptake is one of the factors responsible for the often observed depressed initial state 3 respiration rates in many mitochondrial preparations. Since nonlimiting levels of substrate in the matrix cannot be attained by energy-independent exchange, a dependence on respiration for adequate uptake results. Substrate limitation therefore occurs in the matrix for the period of time needed for energy-dependent accumulation of nonlimiting levels

  8. Studies on biamperometric determination of thorium using EDTA as titrant

    International Nuclear Information System (INIS)

    Jayachandran, Kavitha; Nair, P.R.; Noronha, D.M.; Xavier, Mary; Aggarwal, S.K.

    2009-01-01

    A method is described for the determination of thorium at sub milligram levels by EDTA complexometric titration using biamperometric end point detection. The methodology is based on the electroactive behaviour of EDTA observed at pH 2-3, suggesting a reversible electron transfer reaction at potential ≥ 200 mV applied between twin Pt electrodes. Accuracy and precision of better than 2% were obtained for thorium amounts in the 100-500 μg range. (author)

  9. Amperometric titration of indium with edta solution in propanol

    International Nuclear Information System (INIS)

    Gevorgyan, A.M.; Talipov, Sh.T.; Khadeev, V.A.; Kostylev, V.S.; Khadeeva, L.A.

    1980-01-01

    Optimum conditions have been chosen for titration of indium with EDTA solution in anhydrous propanol and its mixtures with some aprotic solvents using amperometric and point detection. A procedure is suggested of determining indium microcontents in the presence of large amounts of other elements. The procedure is based on its extraction preseparation followed by direct titration in the extract with a standard EDTA solution [ru

  10. FERRIC CITRATE: AN IRON-BASED ORAL PHOSPHATE BINDER

    Directory of Open Access Journals (Sweden)

    T. Christopher Bond

    2012-06-01

    Based on actual physician behavior in response to ferritin and TSAT increases and ferric citrate clinical trial results, and assuming equivalent pricing to other PBs, there would be cost savings with ferric citrate use through reduced ESA and iron use.

  11. The Influence of Phosphate Buffer on the Formation of N-Nitrosodimethylamine from Dimethylamine Nitrosation

    Directory of Open Access Journals (Sweden)

    Long Xu

    2013-01-01

    Full Text Available Buffer solutions were widely used for almost all the investigations concerning N-nitrosodimethylamine (NDMA, a member of powerful mutagenic and carcinogenic compounds which are ubiquitous in the environment. However, whether or how the buffer matrixes influence NDMA formation is still unknown. The effect of buffer solutions on NDMA formation from the nitrosation of dimethylamine (DMA by nitrite (NaNO2 was investigated at pH 6.4 in four kinds of buffer solutions, that is, Na2HPO4/C6H8O7, Na3(C6H5O7/C6H8O7, NaH2PO4/NaOH, and NaH2PO4/Na2HPO4. Our observations demonstrate an unexpected inhibitory effect of the buffer solutions on NDMA formation and the phosphate buffer plays a more significant role in inhibiting NDMA formation compared to the citrate buffer. Moreover, the amount of the phosphate in the buffer was also found to greatly impact the formation of NDMA. A further investigation indicates that it is the interaction between NaH2PO4 and reactant NaNO2 rather than DMA that leads to the inhibitory effect of phosphate buffer during the DMA nitrosation reaction. This study expands the understanding of the influence of buffer solution on nitrosamines formation through the nitrosation pathway and further gives a hint for water plants to reduce the formation of nitrosamines.

  12. Buffer design 2012

    International Nuclear Information System (INIS)

    Juvankoski, M.

    2013-08-01

    Posiva's spent nuclear fuel disposal is based on the KBS-3V concept and on the characteristics of the Olkiluoto site. In this concept single canisters containing spent nuclear fuel surrounded by a bentonite buffer are emplaced in individual vertical boreholes drilled in the floor of deposition tunnels in bedrock at about 420 m depth below ground level. Disk type bentonite blocks are installed at the bottom of the hole and on the top of the disposal canister. Ring type bentonite blocks surround the canisters. This report describes the detailed design of the buffer for a KBS-3V repository. The report presents the design basis, the reference design, and summarises the performance analyses carried out for the design. This report addresses aspects concerning the manufacture, quality control, mechanical strength, chemical resistance, thermal dimensioning, handling of buffer components and material ageing phenomena including the effect of radiation. Interaction of buffer and other engineered barriers are included in the study. The long-term evolution of the repository and its effective drivers are considered if they have an impact on the buffer performance but operational safety aspects are also included because they may affect long-term safety. (orig.)

  13. Synthesis and characterization of the Rhodium (II) citrate complex

    International Nuclear Information System (INIS)

    Najjar, R.; Santos, F.S. dos; Seidel, W.

    1987-01-01

    The preparation and characterization of the rhodium (II) citrate is described. Rhodium citrate was prepared by reacting citric acid trihydrated (3,4 g, 16 mmols) with anhydrous rhodium acetate (0,44 g, 1 mmol). Th electronic instruments, thermogravimetric curve and spectrum of rhodium (II) citrate are analysed. (M.J.C.) [pt

  14. The SVT Hit Buffer

    International Nuclear Information System (INIS)

    Belforte, S.; Dell'Orso, M.; Donati, S.

    1996-01-01

    The Hit Buffer is part of the Silicon Vertex Tracker, a trigger processor dedicated to the reconstruction of particle trajectories in the Silicon Vertex Detector and the Central Tracking Chamber of the Collider Detector at Fermilab. The Hit Buffer is a high speed data-traffic node, where thousands of words are received in arbitrary order and simultaneously organized in an internal structured data base, to be later promptly retrieved and delivered in response to specific requests. The Hit Buffer is capable of processing data at a rate of 25 MHz, thanks to the use of special fast devices like Cache-Tag RAMs and high performance Erasable Programmable Logic Devices from the XILINX XC7300 family

  15. 21 CFR 73.2110 - Bismuth citrate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Bismuth citrate. 73.2110 Section 73.2110 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL LISTING OF COLOR... paragraph (c)(1), effective April 27, 2010. For the convenience of the user, the revised text is set forth...

  16. Myositis ossificans with Ga-67 citrate positivity

    International Nuclear Information System (INIS)

    Moreno, A.J.; Yedinak, M.A.; Spicer, M.J.; Turnbull, G.L.; Byrd, B.F.; Brown, T.J.

    1985-01-01

    A 16 year-old boy presented with a firm mass within the left thigh. Ga-67 citrate and bone scintigraphy revealed soft tissue radiotracer accumulation within the mass lesion. Radiographs and xerography of the left thigh revealed calcification within the soft tissue mass typical of myositis ossificans. The patient's clinical course was uneventful

  17. CaEDTA vs CaEDTA plus BAL to treat children with elevated blood lead levels.

    Science.gov (United States)

    O'Connor, M E

    1992-07-01

    The effectiveness of CaEDTA alone vs CaEDTA plus BAL was compared retrospectively in a group of 72 children with lead levels between 2.41 mumol/L (50 micrograms/dL) and 2.90 mumol/L (60 micrograms/dL). The children who received both drugs had higher median zinc protoporphyrin (ZnP) concentrations at the initiation of therapy than children who received CaEDTA alone (160 micrograms/dL vs 96 micrograms/dL, p less than .01). There was a significantly increased incidence of vomiting and abnormal liver-function test results in the children who received both drugs. The children who received CaEDTA alone had a greater percent mean fall in lead level at one to three weeks postchelation (30.5% vs 18.1%, p less than .05). Children who received both CaEDTA and BAL had a greater percent decrease in ZnP at four to eight months postchelation, but there was no difference in percent decrease in lead levels. Children who received both drugs also had a greater number of repeat courses of chelation by six months. The addition of BAL to CaEDTA for treatment of children with lead levels of 2.41 mumol/L (50 micrograms/dL) to 2.90 mumol/L (60 micrograms/dL) produced greater toxicity and does not seem to prevent repeat chelations within six months.

  18. A parallel buffer tree

    DEFF Research Database (Denmark)

    Sitchinava, Nodar; Zeh, Norbert

    2012-01-01

    We present the parallel buffer tree, a parallel external memory (PEM) data structure for batched search problems. This data structure is a non-trivial extension of Arge's sequential buffer tree to a private-cache multiprocessor environment and reduces the number of I/O operations by the number of...... in the optimal OhOf(psortN + K/PB) parallel I/O complexity, where K is the size of the output reported in the process and psortN is the parallel I/O complexity of sorting N elements using P processors....

  19. Study of Np speciation in citrate medium

    Energy Technology Data Exchange (ETDEWEB)

    Bonin, L.; Den Auwer, C.; Ansoborlo, E.; Moisy, P. [CEA Valrho - DEN/DRCP/SCPS, Bagnols sur Ceze (France); Cote, G. [ENSP - LECA, UMR 7575, Paris (France)

    2007-07-01

    In the framework of the French Environmental Nuclear Toxicology program, additional experiments related to the decorporation of actinides are planned. Decorporation is the removal or release from target organs (bones, liver, kidney..), tissues or cells of radioactive material previously incorporated in them, using chelating agents or other administrated pharmaceutical agents. The contradictory data on the neptunium complexation behaviour within blood and its transfer to target organs, as well as the inefficiency of therapeutic treatments, led us to study the complexation of this element with biological constituents. Within this purpose, the in vitro behaviour of Np(IV) and Np(V) in simple media simulating biological fluids was studied. This study was more specifically focused on the behaviour of neptunium with citrate ion, which is an essential component in a number of metalloenzyme active sites. In order to determine the speciation of this system, spectrophotometry was more particularly used. Concerning the complexation phenomenon, the existence of several complexes of Np(V) with various acido-basic forms of the citrate anion was observed; regarding Np(IV), complexes with Cit{sup 3-} have been observed. From the quantitative study of these equilibria, the values of the absolute constants for the complexation of Np(IV) and Np(V) with citrate were determined. Concerning the stability of neptunium towards oxydo-reduction, it was confirmed that Np(VI) was very quickly reduced to Np(V) by the citrate anions, whereas Np(IV) was stable. In the case of Np(V), it was observed that, depending on the pH and the citrate concentration, Np(V) was unstable and was reduced to Np(IV). The E-pH diagrams, constructed using the stability constants determined in this study, showed that this instability was due to the Np(V) disproportionation. (orig.)

  20. Citrate Anticoagulation during Continuous Renal Replacement Therapy.

    Science.gov (United States)

    Ricci, Davide; Panicali, Laura; Facchini, Maria Grazia; Mancini, Elena

    2017-01-01

    During extracorporeal dialysis, some anticoagulation strategy is necessary to prevent the coagulation of blood. Heparin has historically been used as an anticoagulant because of its efficacy combined with low cost. However, a variable incidence of hemorrhagic complications (5-30%) has been documented in patients undergoing continuous renal replacement therapy (CRRT) with heparin as an anticoagulant. Citrate has anticoagulation properties secondary to its ability to chelate calcium, which is necessary for the coagulation cascade. Citrate may thus be used in a regional anticoagulation (RCA), limited to the extracorporeal circuit of CRRT, to avoid systemic anticoagulation. Recent meta-analysis confirmed the advantage of RCA over heparin in terms of incidence of bleeding during CRRT. Moreover, an increase in filter lifespan is documented, with a secondary advantage in reaching the prescribed dialysis dose. In our experience, we could confirm this positive effect. In fact, with a progressive increase in the proportion of CRRT with citrate as RCA, we obtained a reduction in the number of filters used for every 72 h of treatment (from 2.4 in 2011 to 1.3 in 2015), and most importantly, a reduction in the difference between the prescribed and delivered dialysis doses (from 22 to 7%). Citrate has an intense effect on the acid-base balance as well, if fully metabolized through the Krebs cycle, due to the production of bicarbonate. Even more severely ill patients, such as those with liver dysfunction, may be treated with RCA without severe complications, because modern machines for CRRT are equipped with simple systems that are able to manage the citrate infusion and control the calcium levels, with minimal risks of metabolic derangements. © 2017 S. Karger AG, Basel.

  1. EDTA chelation therapy for cardiovascular disease: a systematic review

    Directory of Open Access Journals (Sweden)

    Wu Ping

    2005-11-01

    Full Text Available Abstract Background Numerous practitioners of both conventional and complementary and alternative medicine throughout North America and Europe claim that chelation therapy with EDTA is an effective means to both control and treat cardiovascular disease. These claims are controversial, and several randomized controlled trials have been completed dealing with this topic. To address this issue we conducted a systematic review to evaluate the best available evidence for the use of EDTA chelation therapy in the treatment of cardiovascular disease. Methods We conducted a systematic review of 7 databases from inception to May 2005. Hand searches were conducted in review articles and in any of the trials found. Experts in the field were contacted and registries of clinical trials were searched for unpublished data. To be included in the final systematic review, the studies had to be randomized controlled clinical trials. Results A total of seven articles were found assessing EDTA chelation for the treatment of cardiovascular disease. Two of these articles were subgroup analyses of one RCT that looked at different clinical outcomes. Of the remaining five studies, two smaller studies found a beneficial effect whereas the other three exhibited no benefit for cardiovascular disease from the use of EDTA chelation therapy. Adverse effects were rare but those of note included a few cases of hypocalcemia and a single case of increased creatinine in a patient on the EDTA intervention. Conclusion The best available evidence does not support the therapeutic use of EDTA chelation therapy in the treatment of cardiovascular disease. Although not considered to be a highly invasive or harmful therapy, it is possible that the use of EDTA chelation therapy in lieu of proven therapy may result in causing indirect harm to the patient.

  2. Buffer Zone Sign Template

    Science.gov (United States)

    The certified pesticide applicator is required to post a comparable sign, designating a buffer zone around the soil fumigant application block in order to control exposure risk. It must include the don't walk symbol, product name, and applicator contact.

  3. Buffer Zone, Nicosia

    OpenAIRE

    Sorensen, Marie Louise

    2010-01-01

    Images of the United Nations Buffer Zone or Green Line which has partitioned Cyprus since 1974 The research leading to these results has received funding from the European Community's Seventh Framework Programme [FP7/2007-2013] under grant agreement n° 217411.

  4. Citrate Anticoagulation for CRRT in Children: Comparison with Heparin

    Directory of Open Access Journals (Sweden)

    Sara Nicole Fernández

    2014-01-01

    Full Text Available Regional anticoagulation with citrate is an alternative to heparin in continuous renal replacement therapies, which may prolong circuit lifetime and decrease hemorrhagic complications. A retrospective comparative cohort study based on a prospective observational registry was conducted including critically ill children undergoing CRRT. Efficacy, measured as circuit survival, and secondary effects of heparin and citrate were compared. 12 patients on CRRT with citrate anticoagulation and 24 patients with heparin anticoagulation were analyzed. Median citrate dose was 2.6 mmol/L. Median calcium dose was 0.16 mEq/kg/h. Median heparin dose was 15 UI/kg/h. Median circuit survival was 48 hours with citrate and 31 hours with heparin (P=0.028. 66.6% of patients treated with citrate developed mild metabolic alkalosis, which was directly related to citrate dose. There were no cases of citrate intoxication: median total calcium/ionic calcium index (CaT/I of 2.16 and a maximum CaT/I of 2.33, without metabolic acidosis. In the citrate group, 45.5% of patients developed hypochloremia and 27.3% hypomagnesemia. In the heparin group, 27.8% developed hypophosphatemia. Three patients were moved from heparin to citrate to control postoperatory bleeding. In conclusion citrate is a safe and effective anticoagulation method for CRRT in children and it achieves longer circuit survival than heparin.

  5. On the Stability of DNA Origami Nanostructures in Low-Magnesium Buffers.

    Science.gov (United States)

    Kielar, Charlotte; Xin, Yang; Shen, Boxuan; Kostiainen, Mauri A; Grundmeier, Guido; Linko, Veikko; Keller, Adrian

    2018-05-25

    DNA origami have great potential as functional platforms in various biomedical applications. Many applications, however, are incompatible with the high Mg2+ concentrations commonly believed to be a prerequisite for maintaining DNA origami integrity. Here, we investigate DNA origami stability in low-Mg2+ buffers. DNA origami stability is found to crucially depend on the availability of residual Mg2+ ions for screening electrostatic repulsion. The presence of EDTA and phosphate ions may thus facilitate DNA origami denaturation by displacing Mg2+ ions from the DNA backbone and reducing the strength of the Mg2+-DNA interaction, respectively. Most remarkably, these buffer dependencies are affected by DNA origami superstructure. However, by rationally selecting buffer components and considering superstructure-dependent effects, the structural integrity of a given DNA origami nanostructure can be maintained in conventional buffers even at Mg2+ concentrations in the low-μM range. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. EDTA modified glassy carbon electrode: Preparation and characterization

    Energy Technology Data Exchange (ETDEWEB)

    Ustuendag, Zafer [Dumlupinar University, Faculty of Arts and Sciences, Department of Chemistry, Kuetahya (Turkey); Solak, Ali Osman [Ankara University, Faculty of Science, Department of Chemistry, Degol Street, Tandogan, 06100 Ankara (Turkey)], E-mail: osolak@science.ankara.edu.tr

    2009-11-01

    EDTA-phenoxyamide modified glassy carbon electrode (EDTA-GC) was prepared at a glassy carbon electrode by surface synthesis. In the first step, nitrophenyl was grafted to the glassy carbon (GC) surface via the electrochemical reduction of its tetraflouroborate diazonium salt. In the second step, nitrophenyl-modified electrode (NP-GC) was subjected to the cathodic potential scan to reduce the nitro to amine group. p-Aminophenyl modified glassy carbon electrode (AP-GC) was dipped into a EDTA solution containing 1-ethyl-3(3-(dimethlyamino)propyl)-carbodiimide (EDC) as an activating agent. Thus formed ((2-anilino-2-oxoethyl){l_brace}2-[bis(carboxymethyl)amino]-ethyl{r_brace}amino)acetic acid modified GC electrode was denoted as EDTA-GC and characterized by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), ellipsometry and X-ray photoelectron spectroscopy (XPS). Complexation of the EDTA-GC surface with Pb{sup 2+} ions was investigated if this electrode could be used as a metal sensor.

  7. A novel mechanism for the pyruvate protection against zinc-induced cytotoxicity: mediation by the chelating effect of citrate and isocitrate.

    Science.gov (United States)

    Sul, Jee-Won; Kim, Tae-Youn; Yoo, Hyun Ju; Kim, Jean; Suh, Young-Ah; Hwang, Jung Jin; Koh, Jae-Young

    2016-08-01

    Intracellular accumulation of free zinc contributes to neuronal death in brain injuries such as ischemia and epilepsy. Pyruvate, a glucose metabolite, has been shown to block zinc neurotoxicity. However, it is largely unknown how pyruvate shows such a selective and remarkable protective effect. In this study, we sought to find a plausible mechanism of pyruvate protection against zinc toxicity. Pyruvate almost completely blocked cortical neuronal death induced by zinc, yet showed no protective effects against death induced by calcium (ionomycin, NMDA) or ferrous iron. Of the TCA cycle intermediates, citrate, isocitrate, and to a lesser extent oxaloacetate, protected against zinc toxicity. We then noted with LC-MS/MS assay that exposure to pyruvate, and to a lesser degree oxaloacetate, increased levels of citrate and isocitrate, which are known zinc chelators. While pyruvate added only during zinc exposure did not reduce zinc toxicity, citrate and isocitrate added only during zinc exposure, as did extracellular zinc chelator CaEDTA, completely blocked it. Furthermore, addition of pyruvate after zinc exposure substantially reduced intracellular zinc levels. Our results suggest that the remarkable protective effect of pyruvate against zinc cytotoxicity may be mediated indirectly by the accumulation of intracellular citrate and isocitrate, which act as intracellular zinc chelators.

  8. Anaerobic Biotransformation and Mobility of Pu and of Pu-EDTA

    Energy Technology Data Exchange (ETDEWEB)

    Xun, Luying

    2009-11-20

    The enhanced mobility of radionuclides by co-disposed chelating agent, ethylenediaminetetraacetate (EDTA), is likely to occur only under anaerobic conditions. Our extensive effort to enrich and isolate anaerobic EDTA-degrading bacteria has failed. Others has tried and also failed. To explain the lack of anaerobic biodegradation of EDTA, we proposed that EDTA has to be transported into the cells for metabolism. A failure of uptake may contribute to the lack of EDTA degradation under anaerobic conditions. We demonstrated that an aerobic EDTA-degrading bacterium strain BNC1 uses an ABC-type transporter system to uptake EDTA. The system has a periplasmic binding protein that bind EDTA and then interacts with membrane proteins to transport EDTA into the cell at the expense of ATP. The bind protein EppA binds only free EDTA with a Kd of 25 nM. The low Kd value indicates high affinity. However, the Kd value of Ni-EDTA is 2.4 x 10^(-10) nM, indicating much stronger stability. Since Ni and other trace metals are essential for anaerobic respiration, we conclude that the added EDTA sequestrates all trace metals and making anaerobic respiration impossible. Thus, the data explain the lack of anaerobic enrichment cultures for EDTA degradation. Although we did not obtain an EDTA degrading culture under anaerobic conditions, our finding may promote the use of certain metals that forms more stable metal-EDTA complexes than Pu(III)-EDTA to prevent the enhanced mobility. Further, our data explain why EDTA is the most dominant organic pollutant in surface waters, due to the lack of degradation of certain metal-EDTA complexes.

  9. Anaerobic Biotransformation and Mobility of Pu and of Pu-EDTA

    International Nuclear Information System (INIS)

    Xun, Luying

    2009-01-01

    The enhanced mobility of radionuclides by co-disposed chelating agent, ethylenediaminetetraacetate (EDTA), is likely to occur only under anaerobic conditions. Our extensive effort to enrich and isolate anaerobic EDTA-degrading bacteria has failed. Others has tried and also failed. To explain the lack of anaerobic biodegradation of EDTA, we proposed that EDTA has to be transported into the cells for metabolism. A failure of uptake may contribute to the lack of EDTA degradation under anaerobic conditions. We demonstrated that an aerobic EDTA-degrading bacterium strain BNC1 uses an ABC-type transporter system to uptake EDTA. The system has a periplasmic binding protein that bind EDTA and then interacts with membrane proteins to transport EDTA into the cell at the expense of ATP. The bind protein EppA binds only free EDTA with a Kd of 25 nM. The low Kd value indicates high affinity. However, the Kd value of Ni-EDTA is 2.4 x 10 -10 nM, indicating much stronger stability. Since Ni and other trace metals are essential for anaerobic respiration, we conclude that the added EDTA sequestrates all trace metals and making anaerobic respiration impossible. Thus, the data explain the lack of anaerobic enrichment cultures for EDTA degradation. Although we did not obtain an EDTA degrading culture under anaerobic conditions, our finding may promote the use of certain metals that forms more stable metal-EDTA complexes than Pu(III)-EDTA to prevent the enhanced mobility. Further, our data explain why EDTA is the most dominant organic pollutant in surface waters, due to the lack of degradation of certain metal-EDTA complexes.

  10. Effect of edta on arsenic phytoextraction by arundo donax

    International Nuclear Information System (INIS)

    Mirza, N.; Pervez, A.; Mahmood, Q.; Shah, M.M.; Farooq, U.

    2014-01-01

    Ligand assisted metal uptake by plants is recent trend in environmental clean-up. Arundo donax L. has been demonstrated as a suitable bioresource for the phytoextraction of arsenic recently. A. donax L. plants were grown in arsenic contaminated soil with doses (5 and 10 mg kg/sup -1/) of Ethylene Diamine Tetra Acetic Acid (EDTA) to investigate chelator-assisted phytoextraction. The arsenic treatments included control (no metal) and five doses of arsenic, i.e., 50, 100, 300, 600 and 1000 micro g kg/sup -1/ . The arsenic concentrations linearly increased in parts of plant with the increasing arsenic and EDTA in growth medium. Ligand addition also resulted in the increased arsenic accumulation in the shoot over its control plants. EDTA additionat the rate 5 mg kg/sup -1/ to the treatment system may effectively increase the arsenic uptake by A. donax without severe growth suppression. (author)

  11. Clomiphene citrate therapy for male infertility.

    Science.gov (United States)

    Allag, I S; Alexander, N J

    1979-11-01

    We have summarized 697 reported cases of the use of clomiphene citrate for the improvement of semen quality. Basal levels of gonadotropins are useful criteria for the differential diagnosis of hypo- and hypergonadotropic hypogonadism. Patients with an intact hypothalamic-pituitary-gonadal axis are most likely to respond to clomiphene citrate. Twenty-five mg. per day, administered in a cyclic fashion for a period of six to nine months, caused the greatest improvement. A higher dose (50 mg. per day) may be effective in men who do not respond to 25 mg. During the course of therapy gonadotropin levels and semen samples should be analyzed periodically. This drug is not currently approved for use in men; the incidence of side effects, particularly with long-term treatment, is unknown.

  12. Pyrolytic citrate synthesis and ozone annealing

    International Nuclear Information System (INIS)

    Celani, F.; Saggese, A.; Giovannella, C.; Messi, R.; Merlo, V.

    1988-01-01

    A pyrolytic procedure is described that via a citrate synthesis allowed us to obtain very fine grained YBCO powders that, after a first furnace thermal treatment in ozone, results already to contain a large amount of superconducting microcrystals. A second identical thermal treatment gives a final product strongly textured, as shown by magnetic torque measurements. Complementary structural and diamagnetic measurement show the high quality of these sintered pellets. The role covered by both the pyrolytic preparation and the ozone annealing are discussed

  13. STABILITY OF SYNTHESIZED SILVER NANOPARTICLES IN CITRATE AND MIXED GELATIN/CITRATE SOLUTION

    Directory of Open Access Journals (Sweden)

    Jana Kavuličová

    2018-04-01

    Full Text Available The study focuses on an investigation of the influence of both citrate and mixed gelatin/citrate as a reductant and stabilizer on the colloidal stability of silver nanoparticles (AgNPssynthesized by a chemical reduction of Ag+ ions after a short - (7th day - and long - (118th day - term storage. Formed AgNPs were characterized by a UV–vis Spectroscopy, Transmission Electron Microscope (TEM, Dynamic light scattering (DLS and Zeta-potential (ZP. The obtained results revealed that a short-term stability of the synthesized AgNPs was greatly influenced by a citrate stabilizer with the absence of gelatin. Smaller-sized AgNPs (average particle diameter of 3 nm, roughly spherical in a shape, were obtained with a narrow size distribution. The very negative value of the Zeta-potential confirmed a strong stability of the citrate capped AgNPs. However, a surface coating of the AgNPs by a gelatin/citrate stabilizer was found to be a dominant contributor in improving a long-term stability of the AgNPs (average particle diameter of 26 nm. The use of gelatin in mixed stabilizer solution provided the AgNPs with higher monodispersity and a controllable size after both the short and long-term storage.

  14. Creep in buffer clay

    International Nuclear Information System (INIS)

    Pusch, R.; Adey, R.

    1999-12-01

    The study involved characterization of the microstructural arrangement and molecular forcefields in the buffer clay for getting a basis for selecting suitable creep models. It is concluded that the number of particles and wide range of the particle bond spectrum require that stochastical mechanics and thermodynamics will be considered and they are basic to the creep model proposed for predicting creep settlement of the canisters. The influence of the stress level on creep strain of MX-80 clay is not well known but for the buffer creep is approximately proportional to stress. Theoretical considerations suggest a moderate impact for temperatures up to 90 deg C and this is supported by model experiments. It is believed that the assumption of strain being proportional to temperature is conservative. The general performance of the stochastic model can be illustrated in principle by use of visco-elastic rheological models implying a time-related increase in viscosity. The shear-induced creep settlement under constant volume conditions calculated by using the proposed creep model is on the order of 1 mm in ten thousand years and up to a couple of millimeters in one million years. It is much smaller than the consolidation settlement, which is believed to be on the order of 10 mm. The general conclusion is that creep settlement of the canisters is very small and of no significance to the integrity of the buffer itself or of the canisters

  15. Simultaneous absorption of NO and SO{sub 2} into Fe-II-EDTA solution coupled with the Fe-II-EDTA regeneration catalyzed by activated carbon

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, H.S.; Mao, Y.P.; Yang, X.J.; Chen, Y.; Long, X.L.; Yuan, W.K. [East China University of Science & Technology, Shanghai (China)

    2010-07-30

    The simultaneous removal of NO and SO{sub 2} from flue gases can be realized with Fe(II)-ethylenediamineteraacetate (EDTA) solution. Activated carbon is used to catalyze the reduction of Fe-III-EDTA to Fe-II-EDTA to maintain the capability of removing NO of the Fe-EDTA solution. The reductant is the sulfite/bisulfite ions produced by SO{sub 2} dissolving into the aqueous solution. Experiments have been performed to determine the effects of activated carbon of coconut shell, Fe-II-EDTA concentration, Fe/EDTA molar ratio, SO{sub 2} partial pressure, NO partial pressure and SO{sub 4}{sup 2-} concentration on the combined elimination of NO and SO{sub 2} with Fe-II-EDTA solution coupled with the Fe-II-EDTA regeneration catalyzed by activated carbon. According to the experimental results, activated carbon not only catalyzes the reduction of Fe-III-EDTA by sulfite/bisulfite greatly but also avoids the release of N{sub 2}O. The NO removal efficiency increases with the initial Fe-II-EDTA concentration and SO{sub 2} partial pressure. The ratio of Fe/EDTA and the SO{sub 4}{sup 2-} concentration has little effect on the catalytic reduction of Fe-III-EDTA. The optimal initial NO concentration range is from 600 ppm to 900 ppm. The experimental results manifest that the Fe-II-EDTA solution coupled with catalytic regeneration of Fe-II-EDTA can maintain high nitric oxide removal efficiency for a long period of time.

  16. Enhanced Fenton-like degradation of TCE in sand suspensions with magnetite by NTA/EDTA at circumneutral pH.

    Science.gov (United States)

    Wang, Na; Jia, Daqing; Jin, Yaoyao; Sun, Sheng-Peng; Ke, Qiang

    2017-07-01

    The present study investigated the degradation of trichloroethylene (TCE) in sand suspensions by Fenton-like reaction with magnetite (Fe 3 O 4 ) in the presence of various chelators at circumneutral pH. The results showed that ethylenediaminetetraacetic acid (EDTA) and nitrilotriacetic acid (NTA) greatly improved the rate of TCE degradation, while [S,S]-ethylenediaminedisuccinic acid (s,s-EDDS), malonate, citrate, and phytic acid (IP6) have minimal effects on TCE degradation. Quenching tests suggested that TCE was mainly degraded by hydroxyl radical (HO · ) attack, with about 90% inhibition on TCE degradation by the addition of HO · scavenger 2-propanol. The presence of 0.1-0.5% Fe 3 O 4 /sand (w/w) contributed to 40% increase in TCE degradation rates. In particular, the use of chelators can avoid high concentrations of H 2 O 2 required for the Fenton-like reaction with Fe 3 O 4 , and moreover improve the stoichiometric efficiencies of TCE degradation to H 2 O 2 consumption. The suitable concentrations of chelators (EDTA and NTA) and H 2 O 2 were suggested to be 0.5 and 20 mM, respectively. Under the given conditions, degradation rate constants of TCE were obtained at 0.360 h -1 with EDTA and 0.526 h -1 with NTA, respectively. Enhanced degradation of TCE and decreased usage of H 2 O 2 in this investigation suggested that Fenton-like reaction of Fe 3 O 4 together with NTA (or EDTA) may be a promising process for remediation of TCE-contaminated groundwater.

  17. Phytoextraction of Pb and Cu contaminated soil with maize and microencapsulated EDTA.

    Science.gov (United States)

    Xie, Zhiyi; Wu, Longhua; Chen, Nengchang; Liu, Chengshuai; Zheng, Yuji; Xu, Shengguang; Li, Fangbai; Xu, Yanling

    2012-09-01

    Chelate-assisted phytoextraction using agricultural crops has been widely investigated as a remediation technique for soils contaminated with low mobility potentially toxic elements. Here, we report the use of a controlled-release microencapsulated EDTA (Cap-EDTA) by emulsion solvent evaporation to phytoremediate soil contaminated with Pb and Cu. Incubation experiments were carried out to assess the effect of Cap- and non-microencapsulated EDTA (Ncap-EDTA) on the mobility of soil metals. Results showed EDTA effectively increased the mobility of Pb and Cu in the soil solution and Cap-EDTA application provided lower and more constant water-soluble concentrations of Pb and Cu in comparison with. Phytotoxicity may be alleviated and plant uptake of Pb and Cu may be increased after the incorporation of Cap-EDTA. In addition phytoextraction efficiencies of maize after Cap- and Ncap-EDTA application were tested in a pot experiment. Maize shoot concentrations of Pb and Cu were lower with Cap-EDTA application than with Ncap-EDTA. However, shoot dry weight was significantly higher with Cap-EDTA application. Consequently, the Pb and Cu phytoextraction potential of maize significantly increased with Cap-EDTA application compared with the control and Ncap-EDTA application.

  18. Dissolution of Fe(III) (hydr) oxides by metal-EDTA complexes

    Science.gov (United States)

    Ngwack, Bernd; Sigg, Laura

    1997-03-01

    The dissolution of Fe(III)(hydr)oxides (goethite and hydrous ferric oxide) by metal-EDTA complexes occurs by ligand-promoted dissolution. The process is initiated by the adsorption of metal-EDTA complexes to the surface and is followed by the dissociation of the complex at the surface and the release of Fe(III)EDTA into solution. The dissolution rate is decreased to a great extent if EDTA is complexed by metals in comparison to the uncomplexed EDTA. The rate decreases in the order EDTA CaEDTA ≫ PbEDTA > ZnEDTA > CuEDTA > Co(II)EDTA > NiEDTA. Two different rate-limiting steps determine the dissolution process: (1) detachment of Fe(III) from the oxide-structure and (2) dissociation of the metal-EDTA complexes. In the case of goethite, step 1 is slower than step 2 and the dissolution rates by various metals are similar. In the case of hydrous ferric oxide, step 2 is rate-limiting and the effect of the complexed metal is very pronounced.

  19. Highly efficient treatment of aerobic vaginitis with simple acidic buffered gels: The importance of pH and buffers on the microenvironment of vaginas.

    Science.gov (United States)

    Sun, Xiaodong; Qiu, Haiying; Jin, Yiguang

    2017-06-15

    Aerobic vaginitis (AV) leads to uterus deep infection or preterm birth. Antibacterial agents are not optimal therapeutics of AV. Here, we report a series of temperature-sensitive in situ forming acidic buffered gels for topical treatment of AV, involving lactate, acetate, and citrate gels at pH 3.5, 5.0, and 6.5. AV rat models were prepared following vaginal infection with Staphylococcus aureus and Escherichia coli. In vitro/in vivo studies of the buffered gels were performed compared with ofloxacin gels and blank gels. All the buffered gels showed the lower in vitro antibacterial activities than ofloxacin gels but the better in vivo anti-S. aureus effects and similar anti-E. coli effects. The buffered gels improved Lactobacillus growth in the vaginas. Both the healthy rat vaginal pH and the pH of rat vaginas treated with the buffered gels were about 6.5 though the AV rat models or ones treated with ofloxacin gels still remained at the high pH more than 7.0. After treatments with the buffered gels, the vaginal smears changed to a clean state nearly without aerobic bacteria, the vaginal tissues were refreshed, and the immunoreactions were downregulated. The acidic buffered gels bring rapid decrease of local vaginal pH, high antibacterial activities, improvement of probiotics, and alleviation of inflammation. They are simple, highly efficient, and safe anti-AV formulations. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Thermophysical properties of carboxylic and amino acid buffers at subzero temperatures: relevance to frozen state stabilization.

    Science.gov (United States)

    Sundaramurthi, Prakash; Suryanarayanan, Raj

    2011-06-02

    Macromolecules and other thermolabile biologicals are often buffered and stored in frozen or dried (freeze-dried) state. Crystallization of buffer components in frozen aqueous solutions and the consequent pH shifts were studied in carboxylic (succinic, malic, citric, tartaric acid) and amino acid (glycine, histidine) buffers. Aqueous buffer solutions were cooled from room temperature (RT) to -25 °C and the pH of the solution was measured as a function of temperature. The thermal behavior of frozen solutions was investigated by differential scanning calorimetry (DSC), and the crystallized phases were identified by X-ray diffractometry (XRD). Based on the solubility of the neutral species of each buffer system over a range of temperatures, it was possible to estimate its degree of supersaturation at the subambient temperature of interest. This enabled us to predict its crystallization propensity in frozen systems. The experimental and the predicted rank orderings were in excellent agreement. The malate buffer system was robust with no evidence of buffer component crystallization and hence negligible pH shift. In the citrate and tartrate systems, at initial pH pI. In the histidine buffer system, depending on the initial pH, either histidine or histidine HCl crystallized.

  1. EFFECTS OF EDTA ON LEA indica) SEEDLINGS REPLANTE ECTS ...

    African Journals Online (AJOL)

    userpc

    Lead (Pb) is one of the widely distributed an most abundant toxic elements in the soil. exerts adverse effects on ... on morphology, growth esses of plants. 1975 ... l plants. The harvesting or EDTA. The pH ntration of Pb2+ before er harvest. The weights .... reported that toxicity symptoms in Indian mustard exposed to Pb and.

  2. Measurement of intestinal permeability using 51Cr-EDTA

    International Nuclear Information System (INIS)

    Peled, Y.; Watz, C.; Gilat, T.

    1985-01-01

    Intestinal permeability tests are a new class of tests of which the 51 Cr-EDTA seemed the easiest to perform. The authors have evaluated the 8- and 24-h urinary excretion of ingested 51 Cr-EDTA in 38 subjects. Twenty-seven patients with diseases not affecting the integrity of the small bowel served as controls. The test group consisted of two patients with celiac, six with Crohn's disease, and three with ulcerative colitis. Nineteen (70.37%) of the control patients had an abnormal test (more than 2.6% in 24 h). The patients with ulcerative colitis had normal excretion (mean 1.95% in 24 h). The patients with celiac disease had an elevated excretion (mean 3.62% in 24 h) and five out of six patients with Crohn's disease also had an increased excretion (mean 6.2% in 24 h). The elevated 51 Cr-EDTA excretion in the control patients casts serious doubts on the validity of the test. Possible causes for abnormal excretion in the controls include various medications used by the patients as well as changes in the chromatographic mobility of 51 Cr-EDTA, demonstrated after incubation with gastric juice

  3. Clomiphene citrate-induced visual hallucinations: a case report

    OpenAIRE

    Venkatesh, Ramesh; Gujral, Gaganjeet Singh; Gurav, Prachi; Tibrewal, Shailja; Mathur, Umang

    2017-01-01

    Background Polycystic ovary syndrome is a common cause of chronic anovulation and infertility in otherwise healthy fertile couples. Clomiphene citrate is used as a first-line ovulation induction therapy in patients with polycystic ovary syndrome. Clomiphene citrate can cause both systemic and ocular side effects. We report a rare side effect of illusory palinopsias in a patient with polycystic ovary syndrome treated with ovulation induction therapy with clomiphene citrate, and emphasize the n...

  4. Buffered or under Scrutiny?

    DEFF Research Database (Denmark)

    Klopf, Patricia; Nell, Phillip C.; Puck, Jonas

    – they are to a stronger extent buffered from the external environment than small firms. Thus, this paper adds to previous research by disentangling the complex effects of size on the use of political strategies – a strand of literature which has been characterized by inconsistent findings in the past.......This paper investigates political strategies of MNE subsidiaries operating in emerging markets. Our findings support previous findings of more intense political strategies in the presence of stronger institutional pressures from public and private stakeholders. Furthermore, we hypothesize...

  5. Aspergillus niger Secretes Citrate to Increase Iron Bioavailability

    Science.gov (United States)

    Odoni, Dorett I.; van Gaal, Merlijn P.; Schonewille, Tom; Tamayo-Ramos, Juan A.; Martins dos Santos, Vitor A. P.; Suarez-Diez, Maria; Schaap, Peter J.

    2017-01-01

    Aspergillus niger has an innate ability to secrete various organic acids, including citrate. The conditions required for A. niger citrate overproduction are well described, but the physiological reasons underlying extracellular citrate accumulation are not yet fully understood. One of the less understood culture conditions is the requirement of growth-limiting iron concentrations. While this has been attributed to iron-dependent citrate metabolizing enzymes, this straightforward relationship does not always hold true. Here, we show that an increase in citrate secretion under iron limited conditions is a physiological response consistent with a role of citrate as A. niger iron siderophore. We found that A. niger citrate secretion increases with decreasing amounts of iron added to the culture medium and, in contrast to previous findings, this response is independent of the nitrogen source. Differential transcriptomics analyses of the two A. niger mutants NW305 (gluconate non-producer) and NW186 (gluconate and oxalate non-producer) revealed up-regulation of the citrate biosynthesis gene citA under iron limited conditions compared to iron replete conditions. In addition, we show that A. niger can utilize Fe(III) citrate as iron source. Finally, we discuss our findings in the general context of the pH-dependency of A. niger organic acid production, offering an explanation, besides competition, for why A. niger organic acid production is a sequential process influenced by the external pH of the culture medium. PMID:28824560

  6. Preparation of electrocatalysts by reduction of precursors with sodium citrate

    OpenAIRE

    Briskeby, Stein Trygve; Tsypkin, Mikhail; Tunold, Reidar; Sunde, Svein

    2014-01-01

    In this work synthesis of Pt/C catalysts by reduction of H2PtCl6 with sodium citrate has been investigated. The strong pH-dependence of citrate as a reducing and stabilizing agent has been explored, and an optimum pH range for production of well dispersed catalysts is proposed. To achieve stabilizing and reducing conditions, the presence of both citrate anions and protonated citrates are required. This is achieved in an intermediate pH range between pKa2 and pKa3 (4.76 and 6.4) of citric acid...

  7. Biotransformation of uranium and transition metal citrate complexes by clostridia

    International Nuclear Information System (INIS)

    Francis, A.J.; Joshi-Tope, G.A.; Dodge, C.J.; Gillow, J.B.

    2002-01-01

    Clostridium sphenoides, which uses citric acid as its sole carbon source, metabolized equimolar Fe(III)-citrate with the degradation of citric acid and the reduction of Fe(III) to Fe(II), but not the U(VI)-citrate complex. However, in the presence of excess citric acid or added glucose it was reduced to U(IV)-citrate. In contrast, Clostridium sp., which ferments glucose but not citrate, reduced Fe(III)-citrate to Fe(II)-citrate and U(VI)-citrate to U(IV)-citrate only when supplied with glucose. These results show that complexed uranium is readily accessible as an electron acceptor despite the bacterium's inability to metabolize the organic ligand complexed to the actinide. These results also show that the metabolism of the metal-citrate complex depends upon the type of complex formed between the metal and citric acid. Fe(III) forms a bidentate complex with citric acid and was metabolized, whereas U forms a binuclear complex with citric acid and was recalcitrant. (author)

  8. Investigating the episodic buffer

    Directory of Open Access Journals (Sweden)

    Alan Baddeley

    2010-10-01

    Full Text Available A brief account is presented of the three-component working memory model proposed by Baddeley and Hitch. This is followed by an account of some of the problems it encountered in explaining how information from different subsystems with different codes could be combined, and how it was capable of communicating with long-term memory. In order to account for these, a fourth component was proposed, the episodic buffer. This was assumed to be a multidimensional store of limited capacity that can be accessed through conscious awareness. In an attempt to test and develop the concept, a series of experiments have explored the role of working memory in the binding of visual features into objects and verbal sequences into remembered sentences. The experiments use a dual task paradigm to investigate the role of the various subcomponents of working memory in binding. In contrast to our initial assumption, the episodic buffer appears to be a passive store, capable of storing bound features and making them available to conscious awareness, but not itself responsible for the process of binding.

  9. Electrospray ionization of uranyl-citrate complexes

    Science.gov (United States)

    Somogyi, Árpád; Pasilis, Sofie P.; Pemberton, Jeanne E.

    2007-09-01

    Results presented here demonstrate the usefulness of electrospray ionization and gas-phase ion-molecule reactions to predict structural and electronic differences in complex inorganic ions. Electrospray ionization of uranyl citrate solutions generates positively and negatively charged ions that participate in further ion-molecule reactions in 3D ion trap and FT-ICR mass analyzers. Most ions observed are derived from the major solution uranyl-citrate complexes and involve species of {(UO2)2Cit2}2-, (UO2)3Cit2, and {(UO2)3Cit3}3-, where Cit indicates the citrate trianion, C6H5O73-. In a 3D ion trap operated at relatively high pressure, complex adducts containing solvent molecules, alkali and ammonium cations, and nitrate or chloride anions are dominant, and proton/alkali cation (Na+, K+) exchange is observed for up to six exchangeable protons in an excess of alkali cations. Adduct formation in a FT-ICR cell that is operated at lower pressures is less dominant, and direct detection of positive and negative ions of the major solution complexes is possible. Multiply charged ions are also detected, suggesting the presence of uranium in different oxidation states. Changes in uranium oxidation state are detected by He-CID and SORI-CID fragmentation, and certain fragments undergo association reactions in trapping analyzers, forming "exotic" species such as [(UO2)4O3]-, [(UO2)4O4]-, and [(UO2)4O5]-. Ion-molecule reactions with D2O in the FT-ICR cell indicate substantial differences in H/D exchange rate and D2O accommodation for different ion structures and charge states. Most notably, the positively charged ions [H2(UO2)2Cit2(H)]+ and [(UO2)2(Cit)]+ accommodate two and three D2O molecules, respectively, which reflects well the structural differences, i.e., tighter uranyl-citrate coordination in the former ion than in the latter. The corresponding negatively charged ions accommodate zero or two D2O molecules, which can be rationalized using suggested solution phase structures

  10. Chloride content of solutions used for regional citrate anticoagulation might be responsible for blunting correction of metabolic acidosis during continuous veno-venous hemofiltration.

    Science.gov (United States)

    Jacobs, Rita; Honore, Patrick M; Diltoer, Marc; Spapen, Herbert D

    2016-08-26

    Citrate, the currently preferred anticoagulant for continuous veno-venous hemofiltration (CVVH), may influence acid-base equilibrium. The effect of 2 different citrate solutions on acid-base status was assessed according to the Stewart-Figge approach in two consecutive cohorts of critically ill adult patients. The first group received Prismocitrate 10/2 (PC10/2; 10 mmol citrate/L). The next group was treated with Prismocitrate 18/0 (PC18; 18 mmol citrate/L). Both groups received bicarbonate-buffered fluids in post-dilution. At similar citrate flow, the metabolic acidosis present at baseline in both groups was significantly attenuated in PC18 patients but persisted in PC10/2 patients after 24 h of treatment (median pH 7,42 vs 7,28; p = 0.0001). Acidosis in the PC10/2 group was associated with a decreased strong ion difference and an increased strong ion gap (respectively 43 vs. 51 mmol/L and 17 vs. 12 mmol/L, PC10/2 vs. PC18; both p = 0.001). Chloride flow was higher in PC10/2 than in PC18 subjects (25.9 vs 14.3 mmol/L blood; p < 0.05). Correction of acidosis was blunted in patients who received 10 mmol citrate/L as regional anticoagulation during CVVH. This could be explained by differences in chloride flow between the applied citrate solutions inducing hyperchloremic acidosis.

  11. Simultaneous decomplexation in blended Cu(II)/Ni(II)-EDTA systems by electro-Fenton process using iron sacrificing electrodes.

    Science.gov (United States)

    Zhao, Zilong; Dong, Wenyi; Wang, Hongjie; Chen, Guanhan; Tang, Junyi; Wu, Yang

    2018-05-15

    This research explored the application of electro-Fenton (E-Fenton) technique for the simultaneous decomplexation in blended Cu(II)/Ni(II)-EDTA systems by using iron sacrificing electrodes. Standard discharge (0.3 mg L -1 for Cu and 0.1 mg L -1 for Ni in China) could be achieved after 30 min reaction under the optimum conditions (i.e. initial solution pH of 2.0, H 2 O 2 dosage of 6 mL L -1  h -1 , current density of 20 mA/cm 2 , inter-electrode distance of 2 cm, and sulfate electrolyte concentration of 2000 mg L -1 ). The distinct differences in apparent kinetic rate constants (k app ) and intermediate removal efficiencies corresponding to mere and blended systems indicated the mutual promotion effect toward the decomplexation between Cu(II) and Ni(II). Massive accumulation of Fe(Ⅲ) favored the further removal of Cu(II) and Ni(II) by metal ion substitution. Species distribution results demonstrated that the decomplexation of metal-EDTA in E-Fenton process was mainly contributed to the combination of various reactions, including Fenton reaction together with the anodic oxidation, electro-coagulation (E-coagulation) and electrodeposition. Unlike hypophosphite and citrate, the presence of chlorine ion displayed favorable effects on the removal efficiencies of Cu(II) and Ni(II) at low dosage, but facilitated the ammonia nitrogen (NH 4 + -N) removal only at high dosage. Copyright © 2018 Elsevier B.V. All rights reserved.

  12. Buffer moisture protection system

    International Nuclear Information System (INIS)

    Ritola, J.; Peura, J.

    2013-11-01

    With the present knowledge, bentonite blocks have to be protected from the air relative humidity and from any moisture leakages in the environment that might cause swelling of the bentonite blocks during the 'open' installation phase before backfilling. The purpose of this work was to design the structural reference solution both for the bottom of the deposition hole and for the buffer moisture protection and dewatering system with their integrated equipment needed in the deposition hole. This report describes the Posiva's reference solution for the buffer moisture protection system and the bottom plate on basis of the demands and functional requirements set by long-term safety. The reference solution with structural details has been developed in research work made 2010-2011. The structural solution of the moisture protection system has not yet been tested in practice. On the bottom of the deposition hole a copper plate which protects the lowest bentonite block from the gathered water is installed straight to machined and even rock surface. The moisture protection sheet made of EPDM rubber is attached to the copper plate with an inflatable seal. The upper part of the moisture protection sheet is fixed to the collar structures of the lid which protects the deposition hole in the disposal tunnel. The main function of the moisture protection sheet is to protect bentonite blocks from the leaking water and from the influence of the air humidity at their installation stage. The leaking water is controlled by the dewatering and alarm system which has been integrated into the moisture protection liner. (orig.)

  13. Diffuse abdominal gallium-67 citrate uptake in salmonella infections

    International Nuclear Information System (INIS)

    Garty, I.; Koren, A.

    1987-01-01

    Two pediatric patients with salmonella infections (one with typhoid fever and the second with salmonella C2 gastroenteritis), had a diffuse abdominal uptake of Ga-67 citrate. The possible explanation for this finding is discussed. Salmonella infection should be included as a cause in the differential diagnosis of diffuse accumulation of Ga-67 citrate

  14. Effectiveness of ranitidine bismuth citrate and proton pump inhibitor ...

    African Journals Online (AJOL)

    Effectiveness of ranitidine bismuth citrate and proton pump inhibitor based triple therapies of Helicobacter pylori in Turkey. ... Results: When we look at the eradication rates of the treatment groups, only two groups (ranitidine bismuth citrate and rabeprazole groups) had eradication rates greater than 80%, both at intention to ...

  15. Citrate increases glass transition temperature of vitrified sucrose preparations

    NARCIS (Netherlands)

    Kets, E.P.W.; Lipelaar, P.J.; Hoekstra, F.A.; Vromans, H.

    2004-01-01

    The aim of this study was to investigate the effect of sodium citrate on the properties of dried amorphous sucrose glasses. Addition of sodium citrate to a sucrose solution followed by freeze-drying or convective drying resulted in a glass transition temperature (T-g) that was higher than the

  16. Two-Buffer Simulation Games

    Directory of Open Access Journals (Sweden)

    Milka Hutagalung

    2016-07-01

    Full Text Available We consider simulation games played between Spoiler and Duplicator on two Büchi automata in which the choices made by Spoiler can be buffered by Duplicator in two different buffers before she executes them on her structure. Previous work on such games using a single buffer has shown that they are useful to approximate language inclusion problems. We study the decidability and complexity and show that games with two buffers can be used to approximate corresponding problems on finite transducers, i.e. the inclusion problem for rational relations over infinite words.

  17. In-EDTA as activable tracer in hydrogeological investigations

    International Nuclear Information System (INIS)

    Stanescu, S.P.; Gaspar, E.; Spiridon, S.; Farcasiu, O.M.; Catilina, R.

    1982-12-01

    Two experiments are presented, on the possibilities of the use of indium in the form of the In-EDTA complex, as an activable tracer for hydrogeological studies. The determination of indium concentrations in the sampled water has been carried out by using the coprecipitation of indium with bismuth hydroxide, the neutron activation at the VVR-S reactor of the Institute for Nuclear Physics and Engineering - Bucharest and the measurement on the 417.0 keV line of sup(116m)In with the Ge(Li) spectrometric device. The advantages of the utilization of In-EDTA as a tracer for marking large volumes of water and of some long transit waters (of the order of months) have resulted. (authors)

  18. Thermometric studies on the Fe(III)-EDTA chelate.

    Science.gov (United States)

    Dot, K

    1978-02-01

    A DeltaH of -11.5 +/- 0.5 kJ/mole has been determined for the formation of the Fe(III)-EDTA chelate at 25.0 degrees and mu = 0.1(= [HClO(4)] + [NaClO(4)]) by a direct thermometric titration procedure. The entropy change, DeltaS, has been calculated to be 440 J.mole(-1) .deg(-1) by combining the result of the heat measurements with the free energy change obtained from the stability constant previously determined. A relationship between the DeltaS values and the standard partial molal entropies of the tervalent metal ions is discussed. In addition, conditions for the thermometric titration of Fe(III) with NA(4)EDTA at room temperature have been investigated. Iron(III) can be determined in the presence of fairly large amounts of phosphate, Cr(III), Mn(II) and Al(III).

  19. Application of cerium(IV)/EDTA complex for future biotechnology

    International Nuclear Information System (INIS)

    Sumaoka, Jun; Chen Wen; Kitamura, Yoshihito; Tomita, Takafumi; Yoshida, Junya; Komiyama, Makoto

    2006-01-01

    A new artificial system for site-selective hydrolysis of single-stranded DNAs was prepared. By using two oligonucleotide additives that bear a monophosphate group at the termini, gap structures were formed at predetermined positions in substrate DNA. The phosphodiester linkages in the gap were efficiently and selectively hydrolyzed by Ce(IV)/EDTA complex (EDTA, ethylenediamine-N,N,N',N'-tetraacetate) at pH 7.0 and 37 deg. C. Furthermore, the fragments formed by the site-selective scission were connected with various oligonucleotides by using T4 DNA ligase, producing desired recombinant DNAs. A new tool for manipulation of single-stranded DNA in biotechnology has been successfully obtained

  20. EDTA fouling in dead-end ultrafiltration of low level radioactive wastewater

    Energy Technology Data Exchange (ETDEWEB)

    Niu, Lixia [Collaborative Innovation Center of Advanced Nuclear Energy Technology, Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084 (China); State Environmental Protection Key Laboratory of Microorganism Application and Risk Control (MARC), Graduate School at Shenzhen, Tsinghua University, Shenzhen, 518055 (China); Zhang, Xue [Collaborative Innovation Center of Advanced Nuclear Energy Technology, Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084 (China); Zhao, Xuan, E-mail: zhxinet@mail.tsinghua.edu.cn [Collaborative Innovation Center of Advanced Nuclear Energy Technology, Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084 (China); Hu, Hongying [Environmental Simulation and Pollution Control State Key Joint Laboratory, School of Environment, Tsinghua University, Beijing 100084 (China); State Environmental Protection Key Laboratory of Microorganism Application and Risk Control (MARC), Graduate School at Shenzhen, Tsinghua University, Shenzhen, 518055 (China)

    2015-12-15

    Highlights: • EDTA in LLRW caused unrecoverable UF membrane fouling. • The rejection of nuclides by UF was significantly enhanced with EDTA addition. • The nuclide (except Ag) deposition on membrane increased with EDTA addition. • Reducing EDTA in the feed water or alkaline/ultrasonic washing were suggested. - Abstract: EDTA is widely used as a detergent, and finally enters into wastewater. The influence of EDTA on ultrafiltration of low level radioactive wastewater (LLRW) was investigated under different operation conditions. As the main organic pollutant, EDTA led to unrecoverable membrane fouling and the normalized flux decreased from 100% to 85% depending on its concentration. The clogging caused by EDTA increased the surface roughness of the membrane, leading to the flux reduction. Both nuclide rejections and depositions on the membrane surfaces were enhanced with EDTA addition, due to the strong complexation of the nuclides with EDTA. However, Ag deposition on the membrane decreased slightly in the presence of EDTA, which may be caused by the stronger attraction of Ag to the unmodified membrane than that to the EDTA-modified one. Transmembrane pressure (TMP) and molecular weight cut off (MWCO) of membranes had negligible effects on membrane fouling, while the nuclide rejections by membrane and the depositions of nuclides on membrane both decreased significantly when the TMP increased to 0.2 MPa and MWCO increased from 5 kDa to 30 kDa. Based on these results, it clearly showed that EDTA even at a low concentration had strong effects on the performance of UF treating LLRW. Therefore, it is suggested for industrial application that pretreatments to reduce EDTA or alkaline/ultrasonic washing involved in UF process were necessary to reduce the nuclide depositions on the membrane surfaces and irradiation dose of membrane surface.

  1. Radiopharmaceuticals of DTPA, DMSA and EDTA labeled with holmium-166

    International Nuclear Information System (INIS)

    Rahman, M.; Matsouka, H.; Takami, S.; Terunuma, K.

    2001-01-01

    DTPA, DMSA and EDTA were labelled with 166 Ho of low specific activity, 250-275mCi/mg of Ho, produced from holmium oxide by the 165 Ho(n, g) 166 Ho reaction at a neutron flux of about 10 14 n.cm -2 .s -1 . Three pH ranges were selected in the study, viz. 2-3, 3-3.5 and 5-6. The labelling reactions were studied as chloride and nitrate solutions in aqueous and saline media at 30 min and 20-24 h of reaction. DTPA was labelled over 99, DMSA at about 90 and EDTA at 100.0% with 166 Ho. The complexes were found stable at all times of investigation. A beta chromatogram scanner was used to study by TLC the labelling reactions of DTPA and DMSA with the nuclide and by PC those of EDTA. A biodistribution study in three rats injected intravenous with a saline solution of 166 HoCl 3 [DTPA] at pH5.1 showed an initial uptake in blood, kidney and lung after 30 minutes. After four hours the complex was found to have cleared from blood and lung, and localized 100% in kidney. It was stable in vivo in the kidney after 24 hours. The g spectrum analysis did not show the formation of any impurity except the four characteristic g energies of 166 Ho. (author)

  2. Simultaneous Removal of Thallium and EDTA by Fenton Process

    Science.gov (United States)

    Xu, Ruibing; Huang, Xuexia; Li, Huosheng; Su, Minhua; Chen, Diyun

    2018-01-01

    The wastewater containing heavy metals and organic pollutants is widely discharged from industries. Because of the coexistence of heavy metals and organic pollutants, the treatment of such wastewater is very difficult. Fenton process is considered to be one of the most effective approaches for the degradation of organic pollutants in aqueous solution due to the strong oxidative ability of hydroxyl radical which generated from the Fenton process. Apart from this, heavy metals are able to be removed during Fenton process owning to the synergic effect of coagulation and precipitation. In this work, pollutants of thallium and EDTA were successfully removed via the Fenton process. A series of single-factor experiments were designed and performed to achieve an optimal reaction conditions for the removal of both thallium and EDTA. Results showed that the removal efficiencies of thallium and TOC could be as high as 96.54% and 70.42%, respectively. The outcomes from our study demonstrate that Fenton process is a promising method for the purification of wastewater containing thallium and EDTA.

  3. Using fractional order method to generalize strengthening generating operator buffer operator and weakening buffer operator

    OpenAIRE

    Wu, L.; Liu, S.; Yang, Yingjie

    2016-01-01

    Traditional integer order buffer operator is extended to fractional order buffer operator, the corresponding relationship between the weakening buffer operator and the strengthening buffer operator is revealed. Fractional order buffer operator not only can generalize the weakening buffer operator and the strengthening buffer operator, but also realize tiny adjustment of buffer effect. The effectiveness of GM(1,1) with the fractional order buffer operator is validated by six cases.

  4. Mechanisms of buffer therapy resistance.

    Science.gov (United States)

    Bailey, Kate M; Wojtkowiak, Jonathan W; Cornnell, Heather H; Ribeiro, Maria C; Balagurunathan, Yoganand; Hashim, Arig Ibrahim; Gillies, Robert J

    2014-04-01

    Many studies have shown that the acidity of solid tumors contributes to local invasion and metastasis. Oral pH buffers can specifically neutralize the acidic pH of tumors and reduce the incidence of local invasion and metastatic formation in multiple murine models. However, this effect is not universal as we have previously observed that metastasis is not inhibited by buffers in some tumor models, regardless of buffer used. B16-F10 (murine melanoma), LL/2 (murine lung) and HCT116 (human colon) tumors are resistant to treatment with lysine buffer therapy, whereas metastasis is potently inhibited by lysine buffers in MDA-MB-231 (human breast) and PC3M (human prostate) tumors. In the current work, we confirmed that sensitive cells utilized a pH-dependent mechanism for successful metastasis supported by a highly glycolytic phenotype that acidifies the local tumor microenvironment resulting in morphological changes. In contrast, buffer-resistant cell lines exhibited a pH-independent metastatic mechanism involving constitutive secretion of matrix degrading proteases without elevated glycolysis. These results have identified two distinct mechanisms of experimental metastasis, one of which is pH-dependent (buffer therapy sensitive cells) and one which is pH-independent (buffer therapy resistant cells). Further characterization of these models has potential for therapeutic benefit. Copyright © 2014 Neoplasia Press, Inc. Published by Elsevier Inc. All rights reserved.

  5. Effect of citrate on Aspergillus niger phytase adsorption and catalytic activity in soil

    Science.gov (United States)

    Mezeli, Malika; Menezes-Blackburn, Daniel; Zhang, Hao; Giles, Courtney; George, Timothy; Shand, Charlie; Lumsdon, David; Cooper, Patricia; Wendler, Renate; Brown, Lawrie; Stutter, Marc; Blackwell, Martin; Darch, Tegan; Wearing, Catherine; Haygarth, Philip

    2015-04-01

    .5 when compared to the free enzymes or in soil solution. The effect of ionic strength on enzyme activity was studied by increasing NaCl concentration on the activity buffer. A significant loss of activity was seen at ionic strengths over 0.6 M but enzymes in soil solution showed increased loss of activity on initial increase in ionic strength. No significant effect of citrate on phytase catalytic efficiency was observed towards free, adsorbed and precipitated (Al, Fe, Ca) phytate, except for the free phytase towards adsorbed phytase which showed a ~160% increase in P release with the addition of citric acid. This data suggest that citrate addition has no impact on the adsorption or catalytic activity of phytase in soil solution or that immobilised on soil particles, suggesting that its impact is associated with the availability of the substrate rather than effects on the enzyme per se. The ionic strength of soil solution does, however, have an impact on phytase activity suggesting that both wetting/drying cycles and fertilisation will have discrete impacts on the activity of phytases once released to soil and thus their ability to make organic P available for uptake by plants and microbes.

  6. Iron(III) citrate speciation in aqueous solution.

    Science.gov (United States)

    Silva, Andre M N; Kong, XiaoLe; Parkin, Mark C; Cammack, Richard; Hider, Robert C

    2009-10-28

    Citrate is an iron chelator and it has been shown to be the major iron ligand in the xylem sap of plants. Furthermore, citrate has been demonstrated to be an important ligand for the non-transferrin bound iron (NTBI) pool occurring in the plasma of individuals suffering from iron-overload. However, ferric citrate chemistry is complicated and a definitive description of its aqueous speciation at neutral pH remains elusive. X-Ray crystallography data indicates that the alcohol function of citrate (Cit4-) is involved in Fe(III) coordination and that deprotonation of this functional group occurs upon complex formation. The inability to include this deprotonation in the affinity constant calculations has been a major source of divergence between various reports of iron(III)-citrate affinity constants. However the recent determination of the alcoholic pKa of citric acid (H4Cit) renders the reassessment of the ferric citrate system possible. The aqueous speciation of ferric citrate has been investigated by mass spectrometry and EPR spectroscopy. It was observed that the most relevant species are a monoiron dicitrate species and dinuclear and trinuclear oligomeric complexes, the relative concentration of which depends on the solution pH value and the iron : citric acid molar ratio. Spectrophotometric titration was utilized for affinity constant determination and the formation constant for the biologically relevant [Fe(Cit)2]5- is reported for the first time.

  7. Direct analysis of ethylenediaminetetraacetic acid (EDTA) on concrete by reactive-desorption electrospray ionization mass spectrometry.

    Science.gov (United States)

    Lebeau, D; Reiller, P E; Lamouroux, C

    2015-01-01

    Analysis of organic ligands such as ethylenediaminetetraacetic acid (EDTA) is today an important challenge due to their ability to increase the mobility of radionuclides and metals. Reactive desorption electrospray ionization mass spectrometry (reactive-DESI-MS) was used for direct analysis of EDTA on concrete samples. EDTA forms complexes and those with Fe(III) ions are among the most thermodynamically favored. This complexing capacity was used to improve the specific detection of EDTA directly on a concrete matrix by doping the solvent spray of DESI with a solution of FeCl3 to selectively create the complex between EDTA and Fe(III). Thus, EDTA sensitivity was largely improved by two orders of magnitude with reactive-DESI-MS experiments thanks to the specific detection of EDTA as a [EDTA-4H+Fe(III)](-) complex. The proof of principle that reactive DESI can be applied to concrete samples to detect EDTA has been demonstrated. Its capacity for semi-quantitative determination and localization of EDTA under ambient conditions and with very little sample preparation, minimizing sample manipulations and solvent volumes, two important conditions for the development of new methodologies in the field of analytical chemistry, has been shown. Copyright © 2014 Elsevier B.V. All rights reserved.

  8. Electrodialysis operation with buffer solution

    Science.gov (United States)

    Hryn, John N [Naperville, IL; Daniels, Edward J [Orland Park, IL; Krumdick, Greg K [Crete, IL

    2009-12-15

    A new method for improving the efficiency of electrodialysis (ED) cells and stacks, in particular those used in chemical synthesis. The process entails adding a buffer solution to the stack for subsequent depletion in the stack during electrolysis. The buffer solution is regenerated continuously after depletion. This buffer process serves to control the hydrogen ion or hydroxide ion concentration so as to protect the active sites of electrodialysis membranes. The process enables electrodialysis processing options for products that are sensitive to pH changes.

  9. The effect of media composition on EDTA degradation by Agrobacterium sp

    International Nuclear Information System (INIS)

    Palumbo, A.V.; Lee, S.Y.; Boerman, P.

    1994-01-01

    EDTA degradation by an Agrobacterium sp. has been examined by quantifying 14 C-labeled CO 2 produced from iron-[2- 14 C] EDTA and by measured loss of nonlabeled EDTA by HPLC. Fe-EDTA degradation resulted in a rise in pH, nitrate concentration, and ammonia concentration. Addition of glycerol resulted in suppression of Fe-EDTA degradation and in a decrease in pH and NH 4 + concentration in the media. Addition of peptone or yeast extract did not affect degradation. Some of the components (e.g., biotin) of the media are not necessary for growth and biodegradation. Although cobalt-EDTA cannot be degraded, ferrous iron can be added to displace the cobalt. The purpose was to relate the results to remediation of radionuclide-contaminated soils. 12 refs., 4 figs., 2 tabs

  10. Evaluation of ethylenediaminetetraacetic acid (EDTA) solution and gel for smear layer removal.

    Science.gov (United States)

    Dotto, Sidney Ricardo; Travassos, Rosana Maria Coelho; de Oliveira, Elias Pandonor Motcy; Machado, Manoel Eduardo de Lima; Martins, José Luiz

    2007-08-01

    The purpose of this in vitro study was to compare the efficacy of 24% ethylenediaminetetraacetic acid (EDTA) gel and 17% EDTA solution in cleaning dentine walls after root canal instrumentation. Thirty human canine teeth were divided into three groups of 10 teeth each. In Group 1, 1% sodium hypochlorite was used as the irrigating solution; in Group 2, 1% sodium hypochlorite was used with 17% EDTA solution; and in Group 3, 1% sodium hypochlorite was used with 24% EDTA gel. The presence of a smear layer was analysed after instrumentation using scanning electron microscopy. The Kruskal-Wallis test revealed a statistical difference (P 0.05). The results indicate that 1% sodium hypochlorite alone does not remove the smear layer and that there was no statistical difference between EDTA gel and EDTA solution in smear layer removal.

  11. Recovery of manganese from manganese oxide ores in the EDTA solution

    Science.gov (United States)

    Zhang, Chao; Wang, Shuai; Cao, Zhan-fang; Zhong, Hong

    2018-04-01

    A new process has been experimentally and theoretically established for the recovery of manganese from manganese oxide ores, mainly including the reductive leaching of manganese by ethylenediaminetetraacetic acid (EDTA), EDTA recovery, and manganese electrolysis. The experimental conditions for this process were investigated. Moderate leaching environment by EDTA with the pH in the range of 5-6 is of benefit to leach manganese from some manganese oxide ores with high-content impurities, such as iron and aluminum. Most of EDTA can be recovered by acidification. A small amount of the residual EDTA in the electrolyte can prevent the generation of anode mud. In addition, trimanganese tetroxide (Mn3O4) can be obtained by the roasting of the EDTA-Mn crystallized product.

  12. Oxidative dehydrogenation of the 2-aminomethylpyridine (EDTA) ruthenium (III) complex

    International Nuclear Information System (INIS)

    Toma, H.E.; Tsurumaki, M.

    1990-01-01

    The oxidative dehydrogenation of the 2-aminomethylpyridine (ampy) ligand coordinated to the (EDTA)RU(III) complex was investigated based on cyclic voltammetry, spectoelectrochemistry and stopped-flow kinetic measurements in aqueous solution. The reaction mechanism is consistent with the deprotonation of the ampy ligand (pk a =7.48), followed by a reversible one-electron transfer step. The intermediate species generated at this step undergoes a metal-induced electron transfer process, with k=227 s -1 , converting into the corresponding 2-iminomethylpyridine complex. (author) [pt

  13. Effects of EDTA-Na (Na ethylenediaminetetraacetate) upon the metabolism of radiostrontium and radioyttrium in mice

    Energy Technology Data Exchange (ETDEWEB)

    Kikuchi, T; Wakisaka, G; Kono, T; Hiroaki, A; Yamamasu, T; Sugawa, I

    1954-01-01

    The toxicity of EDTA-Na, inert Sr (NO/sub 3/)/sub 2/ and Ba (NO/sub 3/)/sub 2/ has been examined. Simultaneous injection of EDTA-Na showed no significant effect upon the distribution of radio-Sr in the bones of mice. The distribution of radio-Y in the bones of mice tended to decrease following the simultaneous subcutaneous injection of /sup 91/Y and EDTA-Na.

  14. [51Cr]EDTA plasma clearance and endogenous creatinine clearance in advanced renal insufficiency

    International Nuclear Information System (INIS)

    Svendsen, U.G.; Munck, O.; Czartoryski, A.; Stafanger, G.

    1978-01-01

    Comparison of [ 51 Cr]EDTA plasma clearance corrected for extrarenal elimination with 24 h endogenous creatinine clearance in patients with advanced renal failure showed that the corrected [ 51 Cr]EDTA clearance was lower than creatinine clearance, and thus might be a better approximation to the glomerular filtration rate in uraemic patients. The corrections cannot be used on [ 51 Cr]EDTA clearance values below the mean extrarenal clearance, averaging 3.7 ml/min. (Auth.)

  15. In vitro comparison of different 24% EDTA gel formulations efficacy on root surface conditioning

    OpenAIRE

    Sousa, Cliciane Portela; Frizzera, Fausto; Batista, Luiz Henrique Carvalho; Dantas, Andrea Abi Rached; Zandim-Barcelos, Daniela Leal; Sampaio, José Eduardo Cezar

    2013-01-01

    INTRODUCTION: The main goal of root biomodification is to modify the root surface in order to improve the repair of periodontal tissues destroyed by periodontal disease. OBJECTIVE: To evaluate the conditioning efficacy of 24% EDTA gel of different trademarks, considering the variables time and application method, by scanning electron microscopy. MATERIAL AND METHOD: 225 samples were randomly assigned to five groups: sterile saline solution (control); 24% EDTA (Santa Paula Pharmacy); 24% EDTA-...

  16. Teratogenic effect of calcium edetate (CaEDTA) in rats and the protective effect of zinc.

    Science.gov (United States)

    Brownie, C F; Brownie, C; Noden, D; Krook, L; Haluska, M; Aronson, A L

    1986-03-15

    The calcium chelate of EDTA (CaEDTA) currently is the drug of choice in the treatment of lead intoxication. This study investigated the teratogenic potential of CaEDTA, administered parenterally during periods of organogenesis and determined if incorporating zinc into EDTA would protect against teratogenic effects. Four doses (2, 4, 6, and 8 mmol/m2/day) of CaEDTA, two concentrations (8 and 20 mmol/m2/day) of ZnEDTA and ZnCaEDTA (molar ratio 0.5:0.5:1) were used, and a saline control (0.9% NaCl). Timed-pregnant Long-Evans rats were assigned at random to the treatment groups, 20 per dose for each chelate and 30 to the saline control. Rats were injected with the chelate or saline solution sc, twice daily during the 11th through 15th days of gestation. Pups removed by cesarean section on the 21st day were processed for osseous and visceral examination. Additional animals per treatment group were used for maternal plasma and liver and fetal zinc determinations. Results showed increases in several abnormalities (submucous cleft, cleft palate, adactyly-syndactyly, curly tail, abnormal rib and vertebrae) with increasing amounts of CaEDTA. No malformations were seen with ZnEDTA at either dose or with ZnCaEDTA at 8 mmol/m2/day. However, submucous cleft was seen in 6 of 20 litters from the dams receiving the higher dose of ZnCaEDTA. It was concluded that CaEDTA is teratogenic in rats at concentrations which, except for decreased weight gain, produce no discernible toxicity to the dam, and which are comparable to the recommended therapeutic dosage in humans (1500 mg/m2/day corresponding to 4 mmol/m2/day). Protection is afforded by incorporating zinc in the chelate.

  17. Heat conductivity of buffer materials

    International Nuclear Information System (INIS)

    Boergesson, L.; Fredrikson, Anders; Johannesson, L.E.

    1994-11-01

    The report deals with the thermal conductivity of bentonite based buffer materials. An improved technique for measuring the thermal conductivity of buffer materials is described. Measurements of FLAC calculations applying this technique have led to a proposal of how standardized tests should be conducted and evaluated. The thermal conductivity of bentonite with different void ratio and degree of water saturation has been determined in the following different ways: * Theoretically according to three different investigations by other researchers. * Laboratory measurements with the proposed method. * Results from back-calculated field tests. Comparison and evaluation showed that these results agreed very well, when the buffer material was almost water saturated. However, the influence of the degree of saturation was not very well predicted with the theoretical methods. Furthermore, the field tests showed that the average thermal conductivity in situ of buffer material (compacted to blocks) with low degree of water saturation was lower than expected from laboratory tests. 12 refs, 29 figs, 11 tabs

  18. Buffers and vegetative filter strips

    Science.gov (United States)

    Matthew J. Helmers; Thomas M. Isenhart; Michael G. Dosskey; Seth M. Dabney

    2008-01-01

    This chapter describes the use of buffers and vegetative filter strips relative to water quality. In particular, we primarily discuss the herbaceous components of the following NRCS Conservation Practice Standards.

  19. The Effect of Polymer Molecular Weight on Citrate Crosslinked ...

    African Journals Online (AJOL)

    Erah

    Purpose: To develop citrate crosslinked chitosan films using chitosan of different molecular weights. (MW) in .... left to stand until trapped air bubbles ... blotted out carefully with filter paper from the .... potential as biodegradable stent coatings. J.

  20. Comparison between high concentration EDTA (24%) and low concentration EDTA (3%) with surfactant upon removal of smear layer after rotary instrumentation: a SEM study.

    Science.gov (United States)

    Daghustani, Mohsen; Alhammadi, Ahmad; Merdad, Khalid; Ohlin, Johan; Erhardt, Fredrik; Ahlquist, Michael

    2011-01-01

    This in vitro study compare cleanliness of tooth canal walls regarding smear layer after final treatment with 24% ethylenediaminetetraaceticacid (EDTA) and 3% EDTA with or without surfactant. Sixty extracted teeth, randomly distributed into four groups, were prepared using ProFile instruments (DENTSPLY, Maillefer, Ballaigues, Switzerland), and subjected to different final irrigation solutions: group A, 24% EDTA; group B, 3% EDTA with surfactant; group C (positive control), 3% EDTA; and group D (negative control), 0.5% sodium hypochlorite. Roots were sectioned, examined and evaluated under scanning electron microscope; microphotographs were taken for the coronal, middle and apical third of each specimen. Statistical analysis showed no difference regarding presence of smear layer between test groups in the coronal and apical sections. They were cleaned in the coronal sections and uncleaned in the apical sections. In the middle section, group B was significantly cleaner (p EDTA did not improve root canal cleanliness and there is no difference between different EDTA concentrations in removing the smear layer.

  1. Programmable pH buffers

    Science.gov (United States)

    Gough, Dara Van; Huber, Dale L.; Bunker, Bruce C.; Roberts, Mark E.

    2017-01-24

    A programmable pH buffer comprises a copolymer that changes pK.sub.a at a lower critical solution temperature (LCST) in water. The copolymer comprises a thermally programmable polymer that undergoes a hydrophobic-to-hydrophilic phase change at the LCST and an electrolytic polymer that exhibits acid-base properties that are responsive to the phase change. The programmable pH buffer can be used to sequester CO.sub.2 into water.

  2. Investigation of hyperfine interactions in hafnium compounds with F1-, OH1-, and EDTA ligands by perturbed γ-γ angular correlation

    International Nuclear Information System (INIS)

    Amaral, Antonio A.; Silva, Andreia dos S.; Lapolli, Andre L.; Carbonari, Artur W.; Saxena, Rajendra N.

    2011-01-01

    In this study the hyperfine parameters, including the dynamical nature, Perturbed Angular Correlation (PAC) spectroscopy was used to measure the hyperfine parameters in molecules of ligand compounds in solutions. The measurements were carried out at 295 K and 77 K using 181 Hf → 181 Ta, as probe nuclei. Samples were prepared by adding a small volume of radioactive solution containing the probe nuclei in aqueous solution, buffer solution and ethylenediaminetetraacetic acid (EDTA) used as a ligand with pH between 4 and 5 which correspond to the pH of the saturated EDTA solution and in buffer solution with pH between 9 and 10. The results made possible to understand the impact of each method for PAC measurements. Finally a comparative analysis for the several methods of inserting of the probe nuclei in the sample was made, considering chemical and nuclear aspects. The lack of measurements in this kind of samples justifies the importance of the obtained results. (author)

  3. Application of the perturbed angular correlation in the investigation of hyperfine interactions in compounds of hafnium, indium and cadmium with F1-, OH1- and EDTA ligands

    International Nuclear Information System (INIS)

    Amaral, Antonio Acleto

    2011-01-01

    In this study the hyperfine parameters, including the dynamical nature, Perturbed Angular Correlation (PAC) spectroscopy was used to measure the hyperfine parameters in molecules of ligand compounds in solutions. The measurements were carried out at 295 K and 77 K using 111 In → 111 Cd, 181 Hf → 181 Ta and 111m Cd → 111 Cd, as probe nuclei. Samples were prepared by adding a small volume of radioactive solution containing the probe nuclei in aqueous solution, buffer solution and ethylenediaminetetraacetic acid (EDTA) used as a ligand with pH 4.3 which correspond to the pH of the saturated EDTA solution and in buffer solution with pH between 9 and 10. The results made possible to understand the impact of each method for PAC measurements. Finally a comparative analysis for the several methods of inserting of the probe nuclei in the sample was made, considering chemical and nuclear aspects. The lack of measurements in this kind of samples justifies the importance of the obtained results. (author)

  4. Investigation of hyperfine interactions in hafnium compounds with F{sup 1-}, OH{sup 1-}, and EDTA ligands by perturbed {gamma}-{gamma} angular correlation

    Energy Technology Data Exchange (ETDEWEB)

    Amaral, Antonio A.; Silva, Andreia dos S.; Lapolli, Andre L.; Carbonari, Artur W.; Saxena, Rajendra N., E-mail: alapolli@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-07-01

    In this study the hyperfine parameters, including the dynamical nature, Perturbed Angular Correlation (PAC) spectroscopy was used to measure the hyperfine parameters in molecules of ligand compounds in solutions. The measurements were carried out at 295 K and 77 K using {sup 181}Hf {yields}{sup 181}Ta, as probe nuclei. Samples were prepared by adding a small volume of radioactive solution containing the probe nuclei in aqueous solution, buffer solution and ethylenediaminetetraacetic acid (EDTA) used as a ligand with pH between 4 and 5 which correspond to the pH of the saturated EDTA solution and in buffer solution with pH between 9 and 10. The results made possible to understand the impact of each method for PAC measurements. Finally a comparative analysis for the several methods of inserting of the probe nuclei in the sample was made, considering chemical and nuclear aspects. The lack of measurements in this kind of samples justifies the importance of the obtained results. (author)

  5. Effect of the association between citric acid and EDTA on root surface etching.

    Science.gov (United States)

    Manzolli Leite, Fabio Renato; Nascimento, Gustavo Giacomelli; Manzolli Leite, Elza Regina; Leite, Amauri Antiquera; Cezar Sampaio, Josá Eduardo

    2013-09-01

    This study aims to compare the clot stabilization on root surfaces conditioned with citric acid and ethylenediamine-tetraacetic acid (EDTA). Scaled root samples (n = 100) were set in fve groups: group I-control group (saline solution); group II (24% EDTA); group III (25% citric acid); group IV (EDTA + citric acid); group V (citric acid + EDTA). Fifty samples were assessed using the root surface modifcation index (RSMI). The other 50 received a blood drop after conditioning. Clot formation was assessed using blood elements adhesion index (BEAI). A blind examiner evaluated photomicrographs. Statistical analysis considered p EDTA employment before citric acid (group-IV) reduced clot formation in comparison to citric acid use alone (group-III). Root conditioning with citric acid alone and before EDTA had the best results for smear layer removal and clot stabilization. EDTA inhibited clot stabilization on root surface and must have a residual activity once it has diminished clot adhesion to root even after citric acid conditioning. Thus, EDTA can be used to neutralize citric acid effects on periodontal cells without affecting clot stabilization. Clinical signifcance: To demonstrate that citric acid use on root surfaces previously affected by periodontal disease may favor clot stabilization and may have a benefcial effect on surgical outcomes. Also, EDTA can be used to neutralize citric acid effects on periodontal cells.

  6. EDTA sample contamination is common and often undetected, putting patients at unnecessary risk of harm.

    Science.gov (United States)

    Sharratt, C L; Gilbert, C J; Cornes, M C; Ford, C; Gama, R

    2009-08-01

    Potassium ethylenediaminetetraacetic acid (EDTA) is a sample tube anticoagulant used for many laboratory analyses. Gross potassium EDTA contamination of blood samples is easily recognised by marked hyperkalaemia and hypocalcaemia. However, subtle contamination is a relatively common, often unrecognised erroneous cause of spurious hyperkalaemia. Potassium EDTA contamination may also cause hypomagnesaemia and hypozincaemia. There are, however, no data on the prevalence of EDTA contamination as a cause of hypocalcaemia, hypomagnesaemia and hypozincaemia. Following a recent service evaluation, we measure EDTA in serum samples from patients with unexplained hyperkalaemia (serum potassium > 6.0 mmol/l). In addition, over a 1-month period EDTA concentrations were measured in hypocalcaemic (serum adjusted calcium samples. Ethylenediaminetetraacetic acid contamination was detected in 31 samples, nine of which were detected by our routine screening programme. The remaining 22 samples represented 14.3% (19/133) of hypocalcaemic samples, 4.8% (5/104) of hypomagnesaemic samples and 1.4% (2/139) of hypozincaemic samples. A total of 25/31 (80.6%) of patients were re-bled, of which 23/25 (92%) results normalised. Factitious hyperkalaemia, hypocalcaemia and hypomagnesaemia caused by potassium EDTA contamination in our studies are relatively common, and if unrecognised may adversely affect patient care and waste scarce healthcare resources. Correct order of draw of blood samples, improved education and routine laboratory screening of EDTA are necessary to prevent and identify EDTA contamination.

  7. Effects of Application of NTA and EDTA on Accumulation of Soil Heavy Metals in Chrysanthemum

    Science.gov (United States)

    Bai, Weiyang

    2018-02-01

    In order to find out the effect of non-bio chelating agent EDTA and bio-chelating agent NTA on soil heavy metal pollution, the effects of different ratio of chelating agent NTA and EDTA on soil heavy metals (Pb, Cu and Cd ), the effects of chelating on content of chlorophyll and vitamin C and the degree of soil nutrient loss were evaluated. The results showed: that the contents of Pb and Cd were the highest in the roots of Chrysanthemum in the treatment (EDTA / NTA = 2: 1). The treatment (EDTA / NTA = 1: 1) was the best chelating agent ratio for the synergistic effect, which can significantly promoted the Chrysanthemum on heavy metal Cu uptake and transport to aboveground. Chrysanthemum were inhibited by all chelating agents treatments, while the content of chlorophyll and vitamin C of the Chrysanthemum physiological indexes were reduced. In the treatment (EDTA = 1), chlorophyll SPAD, vitamin C content reached a minimum of 36 and 38mg · 100g-1, respectively. The nutrient element TN in the leachate were gradually decreased with the time, and the tenth day was significantly lower than the leaching rate of the first day (p treatment (EDTA = 1) >treatment (EDTA / NTA = 2: 1) >treatment (EDTA / NTA = 1: 2)> treatment (NTA = 1). Treatment (EDTA / NTA = 2: 1) was recommended for the chelating agent ratio with the better physiological parameters, the more heavy metal extraction and the less nitrogen and phosphorus loss

  8. Ion chromatographic determination of vanadium (4) and vanadium (5) in the form of EDTA complexes

    International Nuclear Information System (INIS)

    Komarova, T.V.; Obrezkov, O.N.; Shpigun, O.A.

    1991-01-01

    Ion chromatographic behaviour of V 4+ and V 5+ -EDTA complexes (1,2) and V 5+ -EDTA monoperoxo complexes (3) has been studied. The regularities of ion exchange are obeyed for 1 and 3 complexes. These complex anions are strongly retained on HIX-1 anion exchanger. The chromatographic characteristics of 2 change in time, therefore its determination is impossible under the conditions studied. A method has been developed of the simultaneous determination of V 4+ and V 5+ which is based on retarded formation of the V 5+ -EDTA monoperoxo complex in a system of V 4+ -EDTA - H 2 O 2

  9. Electrochemical EDTA recycling with sacrificial Al anode for remediation of Pb contaminated soil

    International Nuclear Information System (INIS)

    Pociecha, Maja; Lestan, Domen

    2010-01-01

    Recycling chelant is a precondition for cost-effective EDTA-based soil remediation. Extraction with EDTA removed 67.5% of Pb from the contaminated soil and yielded washing solution with 1535 mg L -1 Pb and 33.4 mM EDTA. Electrochemical treatment of the washing solution using Al anode, current density 96 mA cm -2 and pH 10 removed 90% of Pb from the solution (by electrodeposition on the stainless steel cathode) while the concentration of EDTA in the treated solution remained the same. The obtained data indicate that the Pb in the EDTA complex was replaced by electro-corroded Al after electro-reduction of the EDTA and subsequently removed from the solution. Additional soil extraction with the treated washing solution resulted in total removal of 87% of Pb from the contaminated soil. The recycled EDTA retained the Pb extraction potential through several steps of soil extraction and washing solution treatment, although part of the EDTA was lost by soil absorption. - Aluminium anode at alkaline pH in conventional electrolytic cell enables efficient recycling of EDTA as a part of soil washing remediation technology.

  10. Enclomiphene Citrate for the Treatment of Secondary Male Hypogonadism

    Science.gov (United States)

    Rodriguez, Katherine M.; Pastuszak, Alexander W.; Lipshultz, Larry I.

    2016-01-01

    Introduction Hypogonadism is a growing concern in an aging male population. Historically treated using exogenous testosterone, concerns about possible adverse effects of testosterone have led physicians to seek alternative treatment approaches. Areas Covered Enclomiphene citrate is the trans isomer of clomiphene citrate, a non-steroidal estrogen receptor antagonist that is FDA-approved for the treatment of ovarian dysfunction in women. Clomiphene citrate has also been used off-label for many years to treat secondary male hypogonadism, particularly in the setting of male infertility. Here we review the literature examining the efficacy and safety of enclomiphene citrate in the setting of androgen deficiency. Expert Opinion Initial results support the conclusion that enclomiphene citrate increases serum testosterone levels by raising luteinizing hormone (LH) and follicle stimulating hormone (FSH) levels, without negatively impacting semen parameters. The ability to treat testosterone deficiency in men while maintaining fertility supports a role for enclomiphene citrate in the treatment of men in whom testosterone therapy is not a suitable option. PMID:27337642

  11. Effect of clomifene citrate plus metformin and clomifene citrate plus placebo on induction of ovulation in women with newly diagnosed polycystic ovary syndrome: randomised double blind clinical trial

    NARCIS (Netherlands)

    Moll, Etelka; Bossuyt, Patrick M. M.; Korevaar, Johanna C.; Lambalk, Cornelis B.; van der Veen, Fulco

    2006-01-01

    OBJECTIVE: To compare the effectiveness of clomifene citrate plus metformin and clomifene citrate plus placebo in women with newly diagnosed polycystic ovary syndrome. DESIGN: Randomised clinical trial. SETTING: Multicentre trial in 20 Dutch hospitals. PARTICIPANTS: 228 women with polycystic ovary

  12. Efeito do EDTA e EDTA-T aplicado de forma ativa na remoção de "smear layer" de superfícies radiculares

    OpenAIRE

    Sampaio, José Eduardo Cezar; Rached, Ricardo Samih Georges Abi; Pilatti, Gibson Luiz; Theodoro, Letícia Helena; Batista, Luiz Henrique Carvalho

    2003-01-01

    The purpose of this study was to compare the removal of root surface smear layer following active application of EDTA gel and EDTA-T (texapon) gel in different concentrations (5%, 10%, 15%, 20% and 24%), using scanning electron microscopy. A total of 220 dentin blocks obtained from the root surfaces of extracted teeth were divided into 3 groups: Group I - (control) application of saline solution (n = 20); Group II - EDTA gel (pH 7.0) was applied in the following concentrations: 5%, 10%, 15%, ...

  13. Generation of Femtosecond Laser-Cut Decellularized Corneal Lenticule Using Hypotonic Trypsin-EDTA Solution for Corneal Tissue Engineering

    Directory of Open Access Journals (Sweden)

    Man-Il Huh

    2018-01-01

    Full Text Available Purpose. To establish an optimized and standardized protocol for the development of optimal scaffold for bioengineering corneal substitutes, we used femtosecond laser to process human corneal tissue into stromal lenticules and studied to find the most efficient decellularization method among various reagents with different tonicities. Methods. The decellularization efficacy of several agents (0.1%, 0.25%, and 0.5% of Triton X-100, SDS, and trypsin-EDTA (TE, resp. with different tonicities was evaluated. Of all protocols, the decellularization methods, which efficiently removed nuclear materials examined as detected by immunofluorescent staining, were quantitatively tested for sample DNA and glycosaminoglycan (GAG contents, recellularization efficacy, and biocompatibilities. Results. 0.5% SDS in hypertonic and isotonic buffer, 0.25% TE in hypotonic buffer, and 0.5% TE in all tonicities completely decellularized the corneal lenticules. Of the protocols, decellularization with hypotonic 0.25 and 0.5% TE showed the lowest DNA contents, while the GAG content was the highest. Furthermore, the recellularization efficacy of the hypotonic TE method was better than that of the SDS-based method. Hypotonic TE-treated decellularized corneal lenticules (DCLs were sufficiently transparent and biocompatible. Conclusion. We generated an ideal protocol for DCLs using a novel method. Furthermore, it is possible to create a scaffold using a bioengineered corneal substitute.

  14. Complexometric determination: Part I - EDTA and complex formation with the Cu2+ ion

    Directory of Open Access Journals (Sweden)

    Rajković Miloš B.

    2002-01-01

    Full Text Available Compounds forming very stable complexes - chelates, have a wide field of application in analytical chemistry. The most famous group of these compounds are complexons. Complexons represent organic polyaminocarbonic acids as for example ethylenediaminetetraacetic acid (EDTA and its salts. The EDTA molecule has six coordinative sites. It is a hexadentate ligands i.e. it has two binding nitrogen atoms and four oxygen atoms from carboxyl groups and it forms complexes with almost all metal ions. EDTA as a tetraprotonic acid, H4Y disociates through four steps, yielding the ions HsY-, H2Y2-, HY3- and Y4-. Which of the EDTA forms will be encountered in a solution, depends on the pH. Due to the poor solubility of EDTA in pure water, as well as in most organic solvents, the disodium salt of EDTA Na2H2Y-2H2O, under the commercial name complexon III, is utilized for analytical determinations. In water, EDTA forms soluble, stabile chelate complexes with all cations, at the molar ratio 1:1, regardless of the charge of the metal ion. In contrast to other equilibria, which are mainly defined by Le Chatellier's principle, equilibria related to metal-EDTA complex formation are also dependent on the influence of the secondary equilibria of EDTA complex formation. Complexing reactions, which are equilibrium reactions, are simultaneously influenced by the following factors: solution pH and the presence of complexing agents which may also form a stabile complex with metal ions. The secondary reaction influence may be viewed and monitored through conditional stability constants. In the first part of the paper, the reaction of the formation of the Cu2+-ion complex with EDTA is analyzed beginning from the main reaction through various influences of secondary reactions on the complex Cu2+-EDTA: pH effect, complexation effect and hydrolysis effect. The equations are given for conditional stability constants, which include equilibrium reactions under actual conditions.

  15. Coaxial atomic force microscope probes for dielectrophoresis of DNA under different buffer conditions

    Science.gov (United States)

    Tao, Yinglei; Kumar Wickramasinghe, H.

    2017-02-01

    We demonstrate a coaxial AFM nanoprobe device for dielectrophoretic (DEP) trapping of DNA molecules in Tris-EDTA (TE) and phosphate-buffered saline (PBS) buffers. The DEP properties of 20 nm polystyrene beads were studied with coaxial probes in media with different conductivities. Due to the special geometry of our DEP probe device, sufficiently high electric fields were generated at the probe end to focus DNA molecules with positive DEP. DEP trapping for both polystyrene beads and DNA molecules was quantitatively analyzed over the frequency range from 100 kHz to 50 MHz and compared with the Clausius-Mossotti theory. Finally, we discussed the negative effect of medium salinity during DEP trapping.

  16. Preparation of lead titanate zirconate from metal citrates

    International Nuclear Information System (INIS)

    Bastos, C.M.R.

    1994-01-01

    Lead titanate zirconate (PZT) preparation from its metal constituent citrates have been investigated. Metal citrates were obtained by forced precipitation using a dehydration alcohol mixture. Salt solutions of lead nitrate and octahydrated zirconyl chloride, and titanium tetrachloride were treated separately with citric acid and ammonium hydroxide. Zirconium, titanium and lead oxides resulted from thermal decomposition of corresponding citrates at 500 0 C, 450 0 C and 250 0 C, respectively. Lead titanate (PT) and lead zirconate (P Z) were obtained by calcining at 450 0 C and 500 0 C, respectively, after adequate heating of citrates mechanically mixed in ethyl ether. PZT samples were obtained with different starting stoichiometry. Rhombohedral PZT-1 53/47 sample was prepared from co precipitating zirconyl ammonium and ammonium lead citrates in presence of ethanolic titanium oxide dispersion, and calcinating at 800 0 C. Rhombohedral PZT-q 52/48 sample was obtained from heating at 500 0 C for 2 hours a mixture of metal citrates coprecipitated by dehydration mixture of acetone-ethanol-formic acid (2:1:0,06). Tetragonal PZT-m stoichiometry 53/47 sample were obtained by calcining at after 600 0 C for 2 hours after heating a mechanically mixed metal citrates. PT phase arose at 400 0 C. PZT-m powders obtained in a range of 400 0 C-800 0 C were isostatically pressed, and sintered at 1100 0 C and 1200 0 C in saturated Pb O atmosphere. Rhombohedral sintered PZT was obtained with 7,78 g.cm -3 at 1200 0 C. (author). 123 refs, 53 figs, 32 tabs

  17. Ocular safety of Viagra, (sildenafil citrate).

    Science.gov (United States)

    Laties, A M; Fraunfelder, F T

    1999-01-01

    To date, sildenafil citrate (Viagra) gives every evidence of being a safe drug for the eye despite a series of expressed concerns. A review of how its ocular safety profile has been identified offers insights into the strengths and weaknesses of present systems and resources for judging the ocular safety of Viagra or, for that matter, of any new drug. Such insights include: The great value of careful, informed assessment of preclinical information gleaned from laboratory experiments. By and large, such assessments point the way toward appropriate clinical evaluation. For Viagra, early in its development it was noted that besides exerting a major inhibitory effect on the intended target, the vascular-associated enzyme phosphodiesterase 5 (PDE5), the drug also exerts a lesser but definite inhibitory effect on the closely related PDE6, located in the retina. For this reason, preclinical evaluation of the drug included electroretinography plus postmortem histology. In addition, an extended eye examination was incorporated into clinical protocols. The often chaotic but invaluable information stream that becomes available once marketing approval has been gained and large populations begin to use a drug. False alarms, misattribution, and erroneous information are the order of the day. Nevertheless, as information accumulates, patterns of response clarify and the true nature of special susceptibility for subpopulations, if any, becomes apparent. A role for the astute clinician remains: Subtle changes or unusual risks for subpopulations can be missed entirely for long periods of time. A manifest need for improvement in evaluation of postmarketing side-effects. This need has led to the establishment of a new discipline: pharmacoepidemiology. In ophthalmology, the National Registry of Drug Induced Ocular Side-Effects maintains a constant and invaluable surveillance. Examples are supplied to illustrate each of these major points: Our presentation will include data gleaned from

  18. Synthesis and characterization of TEP-EDTA-regulated bioactive hydroxyapatite

    Science.gov (United States)

    Haders, Daniel Joseph, II

    Hydroxyapatite (HA), Ca10(PO4)6(OH) 2, the stoichiometric equivalent of the ceramic phase of bone, is the preferred material for hard tissue replacement due to its bioactivity. However, bioinert metals are utilized in load-bearing orthopedic applications due to the poor mechanical properties of HA. Consequently, attention has been given to HA coatings for metallic orthopedic implants to take advantage of the bioactivity of HA and the mechanical properties of metals. Commercially, the plasma spray process (PS-HA) is the method most often used to deposit HA films on metallic implants. Since its introduction in the 1980's, however, concerns have been raised about the consequences of PS-HA's low crystallinity, lack of phase purity, lack of film-substrate chemical adhesion, passivation properties, and difficulty in coating complex geometries. Thus, there is a need to develop inexpensive reproducible next-generation HA film deposition techniques, which deposit high crystallinity, phase pure, adhesive, passivating, conformal HA films on clinical metallic substrates. The aim of this dissertation was to intelligently synthesize and characterize the material and biological properties of HA films on metallic substrates synthesized by hydrothermal crystallization, using thermodynamic phase diagrams as the starting point. In three overlapping interdisciplinary studies the potential of using ethylenediamine-tetraacetic acid/triethyl phosphate (EDTA/TEP) doubly regulated hydrothermal crystallization to deposit HA films, the TEP-regulated, time-and-temperature-dependent process by which films were deposited, and the bioactivity of crystallographically engineered films were investigated. Films were crystallized in a 0.232 molal Ca(NO3)2-0.232 molal EDTA-0.187 molal TEP-1.852 molal KOH-H2O chemical system at 200°C. Thermodynamic phase diagrams demonstrated that the chosen conditions were expected to produce Ca-P phase pure HA, which was experimentally confirmed. EDTA regulation of

  19. Impacts of EDTA on uptake and accumulation of Cu 2+ by spinach ...

    African Journals Online (AJOL)

    The effects of EDTA on Cu2+ uptake by spinach (spinacia oleracea L) seedlings replanted in hydroponic solutions in a greenhouse were investigated. Four week old seedlings were exposed to various doses of Cu2+ (0, 5, 10, 15, and 20mg/L) and constant concentration of EDTA (10mM). During the exposure, the plant ...

  20. Coulometric Titration of Ethylenediaminetetraacetate (EDTA) with Spectrophotometric Endpoint Detection: An Experiment for the Instrumental Analysis Laboratory

    Science.gov (United States)

    Williams, Kathryn R.; Young, Vaneica Y.; Killian, Benjamin J.

    2011-01-01

    Ethylenediaminetetraacetate (EDTA) is commonly used as an anticoagulant in blood-collection procedures. In this experiment for the instrumental analysis laboratory, students determine the quantity of EDTA in commercial collection tubes by coulometric titration with electrolytically generated Cu[superscript 2+]. The endpoint is detected…

  1. Chemodynamics of EDTA in a simulated mixed waste: the Hanford Site's complex concentrate waste

    International Nuclear Information System (INIS)

    Toste, A.P.; Ohnuki, Toshihiko

    1999-01-01

    Enormous stockpiles of mixed wastes at the USDOE's Hanford Site, the original US plutonium production facility, await permanent disposal. One mixed waste derived from reprocessing spent fuel was found to contain numerous nuclear related organics including chelating agents like EDTA and complexing agents, which have been used as decontamination agents, etc. Their presence in actual mixed wastes indicates that the organic content of nuclear wastes is dynamic and complicate waste management efforts. The subjects of this report is the chemo-degradation of EDTA degradation in a simulant Hanford's complex concentrate waste. The simulant was prepared by adding EDTA to an inorganic matrix, which was formulated based on past analyses of the actual waste. Aliquots of the EDTA simulant were withdrawn at different time points, derivatized via methylation and analyzed by gas chromatography and Gc/MS to monitor the disappearance of EDTA and the appearance of its' degradation products. This report also compares the results of EDTA's chemo-degradation to the g-radiolysis of EDTA in the simulant, the subject of a recently published article. Finally based on the results of these two studies, an assesment of the potential impact of EDTA degradation on the management of mixed wastes is offered. (J.P.N.)

  2. Thermophysical tests of buffer materials

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, H. [ITC, Tokyo (Japan); Taniguchi, Wataru

    1999-03-01

    Thermodynamic properties of buffer materials were measured for putting in order thermodynamic constants to be used in the near-field thermal analysis. The thermal diffusivity and thermal conductivity were measured as functions of the water content and temperature to deduce the specific heat. The thermal conductivity and specific heat varied significantly as the water content changed. Obtained values of the specific heat agreed well the expected values calculated based on the constituents of the buffer material. Temperature dependence of the thermodynamic constants was found small below 90degC. From the findings, the thermal conductivity and specific heat of the buffer material were formulated as functions of the water content. Thermodynamic study of powdery bentonite was carried out as well with a purpose of use for filling apertures in the artificial barrier. (H. Baba)

  3. ACETIC ACID AND A BUFFER

    DEFF Research Database (Denmark)

    2009-01-01

    The present invention relates to a composition comprising : a) 0.01-20% wt/wt acetic acid and b) a physiologically tolerable buffer capable of maintaining acetic acid at a pH in the range of 2-7; and use of such a composition as an antimicrobial agent.......The present invention relates to a composition comprising : a) 0.01-20% wt/wt acetic acid and b) a physiologically tolerable buffer capable of maintaining acetic acid at a pH in the range of 2-7; and use of such a composition as an antimicrobial agent....

  4. Using the EDTA Hole Scavenger to Accelerate Decolorization in the Immobilized Photocatalytic Process

    Directory of Open Access Journals (Sweden)

    raziye Asgari

    2015-07-01

    Full Text Available This study investigated the effect of EDTA as a hole scavenger on accelerating the photocatalytic decolorization of direct blue 71 as a non-degradable model pollutant with nano TiO2 powder immobilized on a cementitious bed. For this purpose, 75 mg/L of the dye was decolorized in 75 minutes with 0.03 M of EDTA at a pH level of 6 and under irradiation produced by a 60-W UV-C lamp. This is while decolorization under identical conditions but in the absence of EDTA had been accomplished in 225 minutes. The experiment, therefore, confirmed the accelerating effect of the scavenger on decolorization. The kinetics of the photocatalytic process with EDTA followed a first order reaction with a constant rate of 0.05 min-1, which is 2.5 times faster than the process without EDTA.

  5. Investigation of some critical parameters of buffer conditions for the development of quantum dots-based optical sensors

    International Nuclear Information System (INIS)

    Yuan Jipei; Guo Weiwei; Wang Erkang

    2008-01-01

    The unique surface-sensitive properties make quantum dots (QDs) great potential in the development of sensors for various analytes. However, quantum dots are not only sensitive to a certain analyte, but also to the surrounding conditions. The controlled response to analyte may be the first step in the designing of functional quantum dots sensors. In this study, taking the quenching effect of benzoquinone (BQ) on CdTe QDs as model, several critical parameters of buffer solution conditions with potential effect on the sensors were investigated. The pH value and the concentration of sodium citrate in the buffer solution critically influenced the quenching effects of BQ. Dozens folds elevation of the quenching extents were observed with the increase of concentrations of H + and sodium citrate, and the quenching mechanisms were also fundamentally different with the changes of the surrounding buffer solutions. The quenching models were proposed and analyzed at different buffer conditions. Taking pH values for example, QDs quenching obeyed the sphere of effective quenching model with the sphere radii of 8.29 nm at pH 8.0, the linear Stern-Volmer equation with Stern-Volmer constant of 2.0 x 10 3 mol -1 L at pH 7.0, and the two binding site static quenching model at basic conditions. The elucidation of parameters for assay performance was important in the development of QDs-based optical sensors

  6. Sildenafil citrate (Viagra) enhances vasodilatation in fetal growth restriction.

    Science.gov (United States)

    Wareing, Mark; Myers, Jenny E; O'Hara, Maureen; Baker, Philip N

    2005-05-01

    Fetal growth restriction (FGR) affects up to 8% of all pregnancies and has massive short-term (increased fetal morbidity and mortality) and long-term (increased incidence of cardiovascular disease in adulthood) health implications. Doppler waveform analysis of pregnancies complicated by FGR suggests compromised uteroplacental circulation and placental hypoperfusion. Our aim was to determine whether myometrial small artery function was aberrant in FGR and to assess whether sildenafil citrate could improve vasodilatation in FGR pregnancies. Small arteries dissected from myometrial biopsies obtained at cesarean section from normal pregnant women (n = 27) or women whose pregnancies were complicated by FGR (n = 12) were mounted on wire myographs. Vessels were constricted (with arginine vasopressin or U46619) and relaxed (with bradykinin) before and after incubation with a phosphodiesterase-5 inhibitor, sildenafil citrate. We demonstrated increased myometrial small artery vasoconstriction and decreased endothelium-dependent vasodilatation in vessels from women whose pregnancies were complicated by FGR. Sildenafil citrate significantly reduced vasoconstriction and significantly improved relaxation of FGR small arteries. We conclude that sildenafil citrate improves endothelial function of myometrial vessels from women whose pregnancies are complicated by intrauterine growth restriction. Sildenafil citrate may offer a potential therapeutic strategy to improve uteroplacental blood flow in FGR pregnancies.

  7. Application of the perturbed angular correlation in the investigation of hyperfine interactions in compounds of hafnium, indium and cadmium with F{sup 1-}, OH{sup 1-} and EDTA ligands; Aplicacao da espectroscopia de correlacao angular perturbada na investigacao de interacoes hiperfinas em compostos de hafnio, indio e cadmio com os ligantes F{sup 1-}, OH{sup 1-} e EDTA

    Energy Technology Data Exchange (ETDEWEB)

    Amaral, Antonio Acleto

    2011-07-01

    In this study the hyperfine parameters, including the dynamical nature, Perturbed Angular Correlation (PAC) spectroscopy was used to measure the hyperfine parameters in molecules of ligand compounds in solutions. The measurements were carried out at 295 K and 77 K using {sup 111}In {yields} {sup 111}Cd, {sup 181}Hf {yields} {sup 181}Ta and {sup 111m}Cd {yields}{sup 111}Cd, as probe nuclei. Samples were prepared by adding a small volume of radioactive solution containing the probe nuclei in aqueous solution, buffer solution and ethylenediaminetetraacetic acid (EDTA) used as a ligand with pH 4.3 which correspond to the pH of the saturated EDTA solution and in buffer solution with pH between 9 and 10. The results made possible to understand the impact of each method for PAC measurements. Finally a comparative analysis for the several methods of inserting of the probe nuclei in the sample was made, considering chemical and nuclear aspects. The lack of measurements in this kind of samples justifies the importance of the obtained results. (author)

  8. A Capital Adequacy Buffer Model

    NARCIS (Netherlands)

    D.E. Allen (David); M.J. McAleer (Michael); R.J. Powell (Robert); A.K. Singh (Abhay)

    2013-01-01

    markdownabstract__Abstract__ In this paper, we develop a new capital adequacy buffer model (CABM) which is sensitive to dynamic economic circumstances. The model, which measures additional bank capital required to compensate for fluctuating credit risk, is a novel combination of the Merton

  9. Smoothing type buffer memory device

    International Nuclear Information System (INIS)

    Podorozhnyj, D.M.; Yashin, I.V.

    1990-01-01

    The layout of the micropower 4-bit smoothing type buffer memory device allowing one to record without counting the sequence of input randomly distributed pulses in multi-channel devices with serial poll, is given. The power spent by a memory cell for one binary digit recording is not greater than 0.15 mW, the device dead time is 10 mus

  10. Concentration-dependent Sildenafil citrate (Viagra) effects on ROS production, energy status, and human sperm function.

    Science.gov (United States)

    Sousa, Maria Inês; Amaral, Sandra; Tavares, Renata Santos; Paiva, Carla; Ramalho-Santos, João

    2014-04-01

    Literature regarding the effects of sildenafil citrate on sperm function remains controversial. In the present study, we specifically wanted to determine if mitochondrial dysfunction, namely membrane potential, reactive oxygen species production, and changes in energy content, are involved in in vitro sildenafil-induced alterations of human sperm function. Sperm samples of healthy men were incubated in the presence of 0.03, 0.3, and 3 μM sildenafil citrate in a phosphate buffered saline (PBS)-based medium for 2, 3, 12, and 24 hours. Sperm motility and viability were evaluated and mitochondrial function, i.e., mitochondrial membrane potential and mitochondrial superoxide production were assessed using flow-cytometry. Additionally, adenosine triphosphate (ATP) levels were determined by high performance liquid chromatography (HPLC) analysis. Results show a decrease in sperm motility correlated with the level of mitochondria-generated superoxide, without a visible effect on mitochondrial membrane potential or viability upon exposure to sildenafil. The effect on both motility and superoxide production was higher for the intermediate concentration of sildenafil (0.3 µM) indicating that the in vitro effects of sildenafil on human sperm do not vary linearly with drug concentration. Adenosine triphosphate levels also decreased following sildenafil exposure, but this decrease was only detected after a decrease in motility was already evident. These results suggest that along with the level of ATP and mitochondrial function other factors are involved in the early sildenafil-mediated decline in sperm motility. However, the further decrease in ATP levels and increase in mitochondria-generated reactive oxygen species after 24 hours of exposure might further contribute towards declining sperm motility.

  11. Effects of Acetate-Free Citrate Dialysate on Glycoxidation and Lipid Peroxidation Products in Hemodialysis Patients

    Directory of Open Access Journals (Sweden)

    Atsumi Masuda

    2012-09-01

    Full Text Available Background/Aims: Previous studies have shown the presence of high levels of glycoxidation and lipid peroxidation products in association with atherosclerosis in patients with end-stage kidney disease. Acetates are commonly used buffer for correcting metabolic acidosis in hemodialysis (HD patients. Since the toxic effects of acetates are well established, acetate-free citrate dialysate (AFD has become available in Japan. The objective of the present study was to evaluate the suppressive effects of AFD on oxidative stress in maintenance HD patients by measuring plasma pentosidine and malondialdehyde-modified low-density lipoprotein (MDA-LDL levels as markers for glycoxidation and lipid peroxidation products. Methods: Plasma pentosidine, MDA-LDL and other laboratory parameters were examined on maintenance HD at the Juntendo University Hospital before and after switching to AFD. Results: MDA-LDL levels divided by LDL cholesterol were significantly lower than those before switching to AFD. Furthermore, levels of plasma pentosidine were lower than those before switching to AFD. Stepwise multiple regression analysis revealed that the percent change of the calcium-phosphorus product in the nondiabetic group and that of phosphorus in the diabetic group were predictive variables for the percent change of MDA-LDL/LDL, whereas the percent change of log high-sensitive C-reactive protein and that of systolic blood pressure in the nondiabetic group and that of diastolic blood pressure in the diabetic group were predictive variables for the percent change of plasma pentosidine. Conclusions: It appears that AFD decreases glycoxidation and lipid peroxidation products when compared with acid citrate dextrose in HD patients. The reduction of oxidative stress by AFD during HD may have possible beneficial effects on atherosclerosis through calcium-phosphorus metabolism and blood pressure.

  12. Retention of ionisable compounds on high-performance liquid chromatography XVII. Estimation of the pH variation of aqueous buffers with the change of the methanol fraction of the mobile phase.

    Science.gov (United States)

    Subirats, Xavier; Bosch, Elisabeth; Rosés, Martí

    2007-01-05

    The use of methanol-aqueous buffer mobile phases in HPLC is a common election when performing chromatographic separations of ionisable analytes. The addition of methanol to the aqueous buffer to prepare such a mobile phase changes the buffer capacity and the pH of the solution. In the present work, the variation of these buffer properties is studied for acetic acid-acetate, phosphoric acid-dihydrogenphosphate-hydrogenphosphate, citric acid-dihydrogencitrate-hydrogencitrate-citrate, and ammonium-ammonia buffers. It is well established that the pH change of the buffers depends on the initial concentration and aqueous pH of the buffer, on the percentage of methanol added, and on the particular buffer used. The proposed equations allow the pH estimation of methanol-water buffered mobile phases up to 80% in volume of organic modifier from initial aqueous buffer pH and buffer concentration (before adding methanol) between 0.001 and 0.01 mol L(-1). From both the estimated pH values of the mobile phase and the estimated pKa of the ionisable analytes, it is possible to predict the degree of ionisation of the analytes and therefore, the interpretation of acid-base analytes behaviour in a particular methanol-water buffered mobile phase.

  13. Alkali absorption and citrate excretion in calcium nephrolithiasis

    Science.gov (United States)

    Sakhaee, K.; Williams, R. H.; Oh, M. S.; Padalino, P.; Adams-Huet, B.; Whitson, P.; Pak, C. Y.

    1993-01-01

    The role of net gastrointestinal (GI) alkali absorption in the development of hypocitraturia was investigated. The net GI absorption of alkali was estimated from the difference between simple urinary cations (Ca, Mg, Na, and K) and anions (Cl and P). In 131 normal subjects, the 24 h urinary citrate was positively correlated with the net GI absorption of alkali (r = 0.49, p origin of hypocitraturia. However, the normal dependence was maintained in CDS and in idiopathic hypocitraturia, suggesting that reduced citrate excretion was largely dietary in origin as a result of low net alkali absorption (from a probable relative deficiency of vegetables and fruits or a relative excess of animal proteins).

  14. A test of the citrate method of PMI estimation from skeletal remains.

    Science.gov (United States)

    Wilson, Sarah J; Christensen, Angi M

    2017-01-01

    Citrate content in bone has been shown to be associated with the postmortem interval (PMI), with citrate decreasing after death as a function of time. Here we test this method using porcine ribs for the period of 1-165days after death, and also assess citrate content and variation from samples placed into two different postmortem environments (terrestrial and aquatic). Higher citrate variation, lower citrate recovery, and a weaker association with time were found in this study as compared to others. Citrate content, however, was found to decrease with increasing PMI, and the method was found to be easy and inexpensive to apply. No significant differences were found in citrate loss between terrestrial and aquatic environments. Although more research is needed, citrate content appears to be a promising new approach in estimating PMI from skeletal remains. Published by Elsevier B.V.

  15. Determination of radiation loads from examination of the colon by 67Ga citrate

    International Nuclear Information System (INIS)

    Mihalova, P.; Buncova, M.; Vrba, T.

    2011-01-01

    This paper deals with the determination of radiation loads from examination of the colon by gallium citrate. The average calculated committed effective dose after administration of 5 MBq of 67 Ga-citrate is 2.05 mSv.

  16. Na2EDTA anticoagulant impaired blood samples from the teleost Piaractus mesopotamicus

    Directory of Open Access Journals (Sweden)

    Thaís Heloisa Vaz Farias

    2016-05-01

    Full Text Available Abstract: The present study aimed to evaluate the effects of Na heparin and Na2EDTA on blood of Piaractus mesopotamicus (360.7±42.4g, 26.4±1.0cm. Twenty fishes were sampled in two experiment trials, ten for erythrocyte fragility analysis and ten for hematologic and plasma biochemical study. The blood collected by venous-caudal puncture was fractioned and stored in anticoagulants solution: Na2EDTA 10%, Na2EDTA 3%, Na heparin 5000 IU and Na heparin 100 IU. Plasmatic levels of calcium presented in the Na2EDTA stored samples were about 80% lower than both heparin groups. Blood samples of P. mesopotamicus stored with Na2EDTA demonstrated increase in the hematocrit and MCV, and decrease in MCHC. The dose-response effect was observed in this study. The results are reinforced by the higher levels of plasmatic protein and hemolysis presented in the Na2EDTA 10% stored blood, confirming the deleterious effect of this anticoagulant treatment on the quality of blood samples. Na2EDTA is not indicated to store P. mesopotamicus blood samples, but sodium heparin at 100 IU is the most recommended anticoagulant, since this treatment presented the lower rate of alterations in the stored blood.

  17. Highly concentrated EDTA gel improves cleaning efficiency of root canal preparation in vitro.

    Science.gov (United States)

    Putzer, P; Hoy, L; Günay, H

    2008-12-01

    Debris and smear layer, as a product of mechanical root canal instrumentation, reduce the effectiveness of pharmacological substances to prevent post-treatment diseases and impair direct contact of filling materials with a clean dentinal surface. The aim of this in vitro study was to investigate the presence and localization of debris and smear layer via scanning electron microscope analysis after standardized root canal preparation with different chelating agents. Dentin surfaces received treatment with: (1) 15% ethylenediaminetetraacetic acid (EDTA), (2) 18.6% EDTA (3) and 24% EDTA or without any demineralizing chemicals as control. Forty vertically split human premolars were sputtered and divided into coronal, middle, and apical sections, followed by a randomized, blinded score evaluation using five scores. Pairwise comparisons of all treatment groups against a control group have been performed by Mann-Whitney U test and the Kruskal-Wallis test. Debris grades showed no significant difference between the three regions of the root canals, except for 18.6% EDTA in the central third. Smear layer and smear plug removal was concentration-dependent. Removal of the smear layer in the three areas showed that there was a statistically significant difference between all parts when using 18.6% and 24% EDTA concentrations compared with the control. The best smear layer removal in the apical region was observed using a 24% EDTA gel as chelating agent and lubricant. The usage of EDTA gel >/=18.6% presented a better cleaning regime when compared to the control group.

  18. "Off-the-Shelf" K2-EDTA for Calcific Band Keratopathy.

    Science.gov (United States)

    Lee, Marco E; Ouano, Dean P; Shapiro, Brett; Fong, Andrew; Coroneo, Minas T

    2018-07-01

    To explore the effectiveness of "off-the-shelf" dipotassium-ethylenediaminetetraacetic acid (K2-EDTA) as an alternative to sodium EDTA as chelation therapy in removal of calcific band keratopathy (CBK). This study was a retrospective case series involving 4 patients with CBK who underwent superficial keratectomy and subsequent chelation therapy with K2-EDTA in a single center (Coastal Eye Clinic) by the same surgeon. Visual acuity and symptomatic relief were the main outcomes measured in our study. All 4 participants in this study were female with an average age of 80.3 years. Three of the patients with reasonable baseline visual acuity experienced improved visual acuity at 1 month. The other patient with multiple ocular comorbidities and severely reduced visual potential reported symptomatic pain relief at 1-month follow-up after the intervention. K2-EDTA seems to be an effective alternative to disodium EDTA in its ability to clear calcific plaques and restore visual function. Because of the logistical difficulties associated with acquiring disodium EDTA, and the relative abundance of K2-EDTA in health-care facilities, we believe that our findings warrant further investigation into its use as a more accessible and cost-effective chelating agent in CBK.

  19. Characterization of EDTA-soluble polysaccharides from the scape of Musa paradisiaca (banana).

    Science.gov (United States)

    Raju, T S; Jagadish, R L; Anjaneyalu, Y V

    2001-02-01

    The polysaccharide components present in the scape of Musa paradisiaca (banana) were fractionated into water-soluble (WSP), EDTA-soluble (EDTA-SP), alkali-soluble (ASP) and alkali-insoluble (AISP) polysaccharide fractions [Anjaneyalu, Jagadish and Raju (1997) Glycoconj. J. 14, 507-512]. The EDTA-SP was further fractionated by iso-amyl alcohol into EDTA-SP-A and EDTA-SP-B. The homogeneity of these two polysaccharides was established by repeated precipitation with iso-amyl alcohol, gel-filtration chromatography and sedimentation analysis. The polysaccharides were characterized by monosaccharide composition analysis, methylation linkage analysis, iodine affinity, ferricyanide number, blue value, hydrolysis with alpha-amylase, gold-electron microscopy and X-ray diffraction spectroscopy. Data from all of these studies suggest that EDTA-SP-A is a branched amylose-type alpha-D-glucan and that EDTA-SP-B is a highly branched amylopectin-type polymer. The nature of the branching patterns of these polysaccharides suggests that they are unique to M. paradisiaca.

  20. Effect of EDTA Conditioning on Microleakage of Four Adhesive Systems in Composite Restorations

    Directory of Open Access Journals (Sweden)

    F. Shafiei

    2008-12-01

    Full Text Available Objective: Evaluating the effect of dentin conditioning with EDTA on microleakage of composite resin restorations, using two etch and rinse and two self-etch adhesives.Materials and Methods: One hundred and sixty extracted molars received class V cavity preparations right under the CEJ and were randomly divided into eight groups of 20, usingfour different adhesive systems. These adhesives included Adper Scotchbond Multi-purpose (SBMP, Adper Single Bond (SB, Clearfil SE Bond (CSEB, and Adper Prompt L-Pop (PLP. In the SBMP and SB experimental groups, EDTA was applied instead of phosphoric acid. In the CSEB and PLP experimental groups, EDTA conditioning was added to the bonding process. After thermocycling, the amount of dye penetration was evaluated using stereomicroscope. The data were analyzed using the Kruskal-Wallis and Dunn tests.Results: Two etch and rinse adhesives (SBMP, SB showed a significantly lower micro-leakage than the two self-etch adhesives, CSEB and PLP, (P<0.05. No significant differ-ence was observed among the experimental groups. PLP and CSEB showed significantly less microleakage using EDTA conditioning (P<0.05. There was no significant difference for SBMP and SB when applying either phosphoric acid or EDTA.Conclusion: In the cases of SBMP and SB, EDTA conditioning is as effective as phos-phoric acid in preventing microleakage. In cases of CSEB and PLP, EDTA conditioning can significantly improve the sealing ability.

  1. The thermodynamic-buffer enzymes.

    Science.gov (United States)

    Stucki, J W

    1980-08-01

    Oxidative phosphorylation operates at optimal efficiency if and only if the condition of conductance matching L33/L11 = square root 1-q2 is fulfilled. In this relation L11 is the phenomenological conductance of phosphorylation, L33 the phenomenological conductance of the load, i.e. the irreversible ATP-utilizing processes in the cell, and q the degree of coupling of oxidative phosphorylation driven by respiration. Since during short time intervals L11 and q are constant whereas L33 fluctuates in the cell, oxidative phosphorylation would only rarely operate at optimal efficiency due to violation of conductance matching. This paper demonstrates that the reversible ATP-utilizing reaction catalyzed by adenylate kinase can effectively compensate deviations from conductance matching in the presence of a fluctuating L33 and hence allows oxidative phosphorylation to operate at optimal efficiency in the cell. Since the adenylate kinase reaction was found to buffer a thermodynamic potential, i.e. the phosphate potential, this finding was generalized to the concept of thermodynamic buffering. The thermodynamic buffering ability of the adenylate kinase reaction was demonstrated by experiments with incubated rat-liver mitochondria. Considerations of changes introduced in the entropy production by the adenylate kinase reaction allowed to establish the theoretical framework for thermodynamic buffering. The ability of thermodynamic buffering to compensate deviations from conductance matching in the presence of fluctuating loads was demonstrated by computer simulations. The possibility of other reversible ATP-utilizing reactions, like the ones catalyzed by creatine kinase and arginine kinase, to contribute to thermodynamic buffering is discussed. Finally, the comparison of the theoretically calculated steady-stae cytosolic adenine nucleotide concentrations with experimental data from perfused livers demonstrated that in livers from fed rats conductance matching is fulfilled on a

  2. Decontamination effectiveness of mixtures of citric acid, oxalic acid and EDTA

    International Nuclear Information System (INIS)

    Speranzini, R.A.

    1990-01-01

    An experimental study of the decontamination effectiveness of citric acid, oxalic acid and EDTA mixtures was conducted to assess whether oxalic acid could be removed from decontamination solutions to minimize corrosion. In loop experiments, radioactive specimens from two boiling water reactors and one pressurized water reactor were suspended in solutions of single acids or in mixtures of reagents at total reagent concentrations of less than 0.1 wt% under conditions similar to those used to decontaminate reactor systems. Rate constants for dissolution of oxides and decontamination factors were measured. Based on the results, it was concluded that under certain conditions, oxalic acid was the most effective reagent for the dissolution of oxides. It was also found, however, that conditions under which effective dissolution occurred in solutions of oxalic acid and/or citric acid were difficult to define and control. EDTA was found to be an effective reagent for dissolution of oxides such that rates of dissolution in EDTA containing solutions at 117 degrees Celsius were comparable to rates in oxalic acid containing solutions. At 90 degrees Celsius, EDTA acted synergistically with oxalic acid such that the rate of dissolution of oxides in citric-acid/oxalic-acid/EDTA solutions was higher than in citric-acid/EDTA solutions. The rates of dissolution of oxides were significantly reduced when 60 mg/kg of ferric ion was added to the citric-acid/oxalic-acid, citric-acid/EDTA and citric-acid/oxalic-acid/EDTA solutions. It was concluded that effective decontaminations of BWR and PWR systems could be achieved with mixtures of citric acid and EDTA

  3. Hemodiafiltration using pre-dilutional on-line citrate dialysate: A new technique for regional citrate anticoagulation: A feasibility study

    Directory of Open Access Journals (Sweden)

    Radhouane Bousselmi

    2015-01-01

    Full Text Available A prospective, observational, feasibility study was carried out on four patients with end-stage renal failure undergoing bicarbonate hemodialysis to study the feasibility of an on-line hemodiafiltration technique using a citrate dialysate with pre-dilutional infusion of citrate as a technique for regional citrate anticoagulation. All patients had contraindication to systemic heparin anticoagulation. The dialysis technique consisted of an on-line hemodiafiltration with a citrate dialysate without calcium using a Fresenius 4008S dialysis machine and Fresenius Polysulfone F60 dialyzers. The infusion solution was procured directly from the dialysate and was infused into the arterial line. To avoid the risk of hypocalcemia, calcium gluconate was infused to the venous return line. The study was carried out in two stages. During the first stage, the citrate infusion rate was 80 mL/min and the calcium infusion rate was 9 mmol/h. At the second stage, the rates were 100 mL/min and 11 mmol/h, respectively. The primary endpoint of this study was the incidence of thrombosis in the extracorporeal blood circuit and/or the dialyzer. A total of 78 sessions were conducted. All the sessions were well tolerated clinically and there were no major incidents in any of the four patients. At the first stage of the study, there were five incidences of small clots in the venous blood chamber, an incidence of extracorporeal blood circuit thrombosis of 12.5%. At the second stage of the study, no cases of extracorporeal blood circuit or dialyzer thrombosis were noted. Hemodiafiltration with on-line citrate dialysate infusion to the arterial line is safe and allows an effective regional anticoagulation of the extracorporeal blood circuit without the need for systemic anticoagulation.

  4. A Comparative Study of [CaEDTA](2-) and [MgEDTA](2-): Structural and Dynamical Insights from Quantum Mechanical Charge Field Molecular Dynamics.

    Science.gov (United States)

    Tirler, Andreas O; Hofer, Thomas S

    2015-07-09

    Structure and dynamics of [MgEDTA](2-) and [CaEDTA](2-) complexes in aqueous solution have been investigated via quantum mechanical/molecular mechanical (QM/MM) simulations. While for the first a 6-fold octahedral complex has been observed, the presence of an additional coordinating water ligand has been observed in the latter case. Because of rapidly exchanging water molecules, this 7-fold coordination complex was found to form pentagonal bipyramidal as well as capped trigonal prismatic configurations along the simulation interchanging on the picosecond time scale. Also in the case of [MgEDTA](2-) a trigonal prismatic configuration has been observed for a very short time period of approximately 1 ps. This work reports for the first time the presence of trigonal prismatic structures observed in the coordination sphere of [MgEDTA](2-) and [CaEDTA](2-) complexes in aqueous solution. In addition to the detailed characterization of structure and dynamics of the systems, the prediction of the associated infrared spectra indicates that the ion-water vibrational mode found at approximately 250 cm(-1) provides a distinctive measure to experimentally detect the presence of the coordinating water molecule via low-frequency IR setups.

  5. Phosphorus Elimination at Sodium Silicate from Quartz Sand Roasted with Complexation using Chitosan-EDTA

    Science.gov (United States)

    Wahyuningsih, S.; Ramelan, A. H.; Suharty, N. S.; Handayani, M.; Firdiyono, F.; Sulistiyono, E.; Munawaroh, H.; Sari, P. P.; Kristiawan, Y. R.

    2018-03-01

    A phosphorus elimination from sodium silicate solution has been studied. Phosphorus elimination was performed by adding chitosan-EDTA to remove cation phosphorus. Characterization of chitosan-EDTA material was performed using FT-IR, while the decreasing level of phosphorus content was analyzed by quantitative analysis using spectrophotometer UV-Vis refers to SNI 06-6989-2004. The results showed that the content of the sodium silicate can be reduced up to 67.1% through Chitosan-EDTA complexation with phosphorus.

  6. Synthesis and Characterization of EDTA Complexes Useful for Trace Elements Supplementation

    Directory of Open Access Journals (Sweden)

    Baran Enrique J.

    2002-01-01

    Full Text Available The synthesis of two heterobimetallic EDTA complexes, MgCu(EDTA.6H2O and ZnCu(EDTA.6H2O, is described. They were characterized by means of vibrational (infrared and Raman and electronic (reflectance spectroscopy. Several dissolution tests in 0.1 N HCl and simulated gastric juice were also performed. The results support the potential usefulness of these complexes for copper supplementation in human and veterinary medicine and to the simultaneous reinforcement of Mg(II and Zn(II levels.

  7. Potentiometric end point detection in the EDTA titrimetric determination of gallium

    International Nuclear Information System (INIS)

    Gopinath, N.; Renuka, M.; Aggarwal, S.K.

    2001-01-01

    Gallium is titrated in presence of known amount of Fe (III) with EDTA in HNO 3 solution at pH 2 to 3. The end point is detected potentiometrically employing a bright platinum wire - saturated calomel (SCE) reference electrode system, the redox couple being Fe (III) / Fe (II). Since Fe (III) is also titrated by EDTA, it is, therefore, subtracted from titre value to get the EDTA equivalent to gallium only. Precision and accuracy 0.2 to 0.4% was obtained in the results of gallium in the range of 8 to 2 mg. (author)

  8. A scanning electron microscopy study of root surface smear layer removal after topical application of EDTA plus a detergent

    OpenAIRE

    Sampaio,José Eduardo Cezar; Campos,Flávia Pavan; Pilatti,Gibson Luiz; Theodoro,Letícia Helena; Leite,Fábio Renato Manzolli

    2005-01-01

    The aim of the present study was to compare root surface smear layer removal following topical application of EDTA and EDTA-T (Texapon). Extracted human teeth had their cementum removed and were mechanically scaled. A total of 220 root specimens were obtained and were randomly assigned to the following groups: I-saline solution (control), II-EDTA; III-EDTA-T. Groups II and III specimens were assigned to different EDTA gel concentrations: 5%, 10%, 15%, 20% and 24%. Smear layer removal score wa...

  9. Buffer substitution in malaria rapid diagnostic tests causes false-positive results

    Directory of Open Access Journals (Sweden)

    Van den Ende Jef

    2010-07-01

    Full Text Available Abstract Background Malaria rapid diagnostic tests (RDTs are kits that generally include 20 to 25 test strips or cassettes, but only a single buffer vial. In field settings, laboratory staff occasionally uses saline, distilled water (liquids for parenteral drugs dilution or tap water as substitutes for the RDT kit's buffer to compensate for the loss of a diluent bottle. The present study assessed the effect of buffer substitution on the RDT results. Methods Twenty-seven RDT brands were run with EDTA-blood samples of five malaria-free subjects, who were negative for rheumatoid factor and antinuclear antibodies. Saline, distilled water and tap water were used as substitute liquids. RDTs were also run with distilled water, without adding blood. Results were compared to those obtained with the RDT kit's buffer and Plasmodium positive samples. Results Only eight cassettes (in four RDT brands showed no control line and were considered invalid. Visible test lines occurred for at least one malaria-free sample and one of the substitutes in 20/27 (74% RDT brands (saline: n = 16; distilled water: n = 17; and tap water: n = 20, and in 15 RDTs which were run with distilled water only. They occurred for all Plasmodium antigens and RDT formats (two-, three- and four-band RDTs. Clearance of the background of the strip was excellent except for saline. The aspects (colour, intensity and crispness of the control and the false-positive test lines were similar to those obtained with the RDT kits' buffer and Plasmodium positive samples. Conclusion Replacement of the RDT kit's dedicated buffer by saline, distilled water and tap water can cause false-positive test results.

  10. 76 FR 19997 - Determination That FENTORA (Fentanyl Citrate) Buccal Tablet, 300 Micrograms, Was Not Withdrawn...

    Science.gov (United States)

    2011-04-11

    ...] Determination That FENTORA (Fentanyl Citrate) Buccal Tablet, 300 Micrograms, Was Not Withdrawn From Sale for... Food and Drug Administration (FDA) has determined that FENTORA (fentanyl citrate) buccal tablet, 300... allow FDA to approve abbreviated new drug applications (ANDAs) for fentanyl citrate buccal tablet, 300...

  11. Urban Runoff: Model Ordinances for Aquatic Buffers

    Science.gov (United States)

    Aquatic Buffers serve as natural boundaries between local waterways and existing development. The model and example ordinaces below provide suggested language or technical guidance designed to create the most effective stream buffer zones possible.

  12. Buffer Zone Requirements for Soil Fumigant Applications

    Science.gov (United States)

    Updated pesticide product labels require fumigant users to establish a buffer zone around treated fields to reduce risks to bystanders. Useful information includes tarp testing guidance and a buffer zone calculator.

  13. Swelling characteristics of buffer material

    International Nuclear Information System (INIS)

    Suzuki, Hideaki; Fujita, Tomoo

    1999-12-01

    After emplacement of the engineered barrier system (EBS), it is expected that the near-field environment will be impacted by phenomena such as heat dissipation by conduction and other heat transfer mechanism, infiltration of groundwater from the surrounding rock into the EBS, generation of swelling pressure in the buffer due to water infiltration and the stress imposed by the overburden pressure. These phenomena are not all independent, but can be strongly influenced by, and coupled with, each other. Evaluating these coupled thermo-hydro-mechanical phenomena is important in order to clarify the initial transient behavior of the engineered barrier system within the near-field. This report describes the results on measurement of swelling amount and stress at boundary built up under restraint condition with water uptake. The following results are identified. (1) The swelling stress of buffer material at saturated condition tends to be independent of effects of pore water pressure and synthetic sea water, and to decrease with increasing temperature. The swelling stress can be explained by the effective dry density. (2) The strain due to swelling estimated from the results of the swelling amount of buffer material is proportional to swelling stress. (3) The swelling stress and strain under unsaturated condition increase with water uptake. (author)

  14. Enhanced citrate production through gene insertion in Aspergillus niger

    DEFF Research Database (Denmark)

    Jongh, Wian de; Nielsen, Jens

    2007-01-01

    The effect of inserting genes involved in the reductive branch of the tricarboxylic acid (TCA) cycle on citrate production by Aspergillus niger was evaluated. Several different genes were inserted individually and in combination, i.e. malate dehydrogenase (mdh2) from Saccharomyces cerevisiae, two...

  15. Scintiscanning of lung cancer with 67Ga-citrate

    International Nuclear Information System (INIS)

    Abe, Mitsunobu; Ohyama, Shiro; Ohtsuka, Hassau; Hoshina, Toshifumi; Takanashi, Shuko

    1982-01-01

    The clinical value of scintigram with 67 Ga-citrate in 58 patients with primary lung cancer was investigated and discussed. The results are as follows: 1) Positive 67 Ga-scintigram was obtained in 83% of patients with primary lung cancer. The histologically confirmed positive ratios were 74% in adenocarcinoma, 94% in squamous cell carcinoma, 80% in small cell carcinoma and 100% in large cell carcinoma. 2) The positive ratios according to T category of TNM classification was 0% (0/1) in T1, 83% (20/24) in T2 and 85% (28/33) in T3. 3) According to rules for classification of lung cancer (TNM UICC 1978,) T2 cases were divided into two groups. a) In patients with hilar involvements on chest X-ray, positive accumulation to the hilar region was 88% (7/8). b) In patients without the evidence of hilar involvements on chest X-ray, the positive accumulation to the hilar region was 81% (13/16). 4) All cases extending to the mediastinum showed abnormal 67 Ga-citrate accumulation regardless of histological type. 67 Ga-citrate scanning is useful in evaluating the extent of lung cancer, especially with hilar and mediastinal involvements. Therefore 67 Ga-citrate scanning seems to be very useful for planning the radiotherapy for lung cancer. (author)

  16. 21 CFR 172.370 - Iron-choline citrate complex.

    Science.gov (United States)

    2010-04-01

    ....370 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) FOOD ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Special Dietary and Nutritional Additives § 172.370 Iron-choline citrate complex. Iron-choline...

  17. The Effect of Polymer Molecular Weight on Citrate Crosslinked ...

    African Journals Online (AJOL)

    SEM), dissolution studies and differential scanning calorimetry (DSC) for surface ... Conclusion: The citrate-crosslinked chitosan films can be modulated to vary swelling and drug release at pH 3.5 and 6.2; this feature makes them useful tools for ...

  18. Acute effect of citrate bath on postdialysis alkalaemia

    Directory of Open Access Journals (Sweden)

    Patricia De Sequera Ortiz

    2015-03-01

    Conclusion: Dialysis with citrate provides better control of postdialysis acid-base balance, decreases/avoids postdialysis alkalaemia, and lowers the increase in Cac and Cai. This finding is of special interest in patients with predisposing factors for arrhythmia and patients with respiratory failure, carbon dioxide retention, calcifications and advanced liver disease.

  19. Ovarian capsular drilling in the treatment of clomiphene citrate ...

    African Journals Online (AJOL)

    Background: Laparoscopic Ovarian Drilling (LOD) is an effective and a well evaluated surgical Treatment of Clomiphene Citrate resistant Polycystic ovarian syndrome. Transvaginal hydrolaparoscopy (TVHL) is a relatively new simple method of exploring the pelvis and has recently been introduced as a transvaginal ...

  20. Interaction of ruthenium (4) and osmium (4) with 2-mercaptobenzimidazole, 2-mercaptobenzoxazole and 2-mercaptobenzothiazole in the presence of edta

    International Nuclear Information System (INIS)

    Busev, A.I.; Ignat'eva, T.I.; Lomakina, L.N.

    1975-01-01

    Interaction of ruthenium (4) and osmium (4) with 2-mercaptobenzimidazole (2MBI), 2-mercaptobenzoxazole (2MBO) and 2-mercaptobenzothiazole (2MBT) in the presence of EDTA was studied. The interaction of ruthenium (4) and osmium (4) with EDTA was constidered. Ruthenium complex is formed with constant output at 2-4.5 pH after 30 min.heating. In the lowacid solution (pH 2-4) osmium reacts with EDTA forming soluble compound. Characteristics of ruthenium (4) compound with 2MBI, 2MBO and 2MBT produced in the presence of EDTA are presented. Osmium (4) in the presence of EDTA and above mentioned organic reagents and when heating forms lowsoluble compounds. Possibility of joint determination of ruthenium and osmium with help of 2MBI in the presence of EDTA under conditions of minimum complexing osmium with EDTA was investigated

  1. Interaction of ruthenium (4) and osmium (4) with 2-mercaptobenzimidazole, 2-mercaptobenzoxazole and 2-mercaptobenzothiazole in the presence of EDTA

    Energy Technology Data Exchange (ETDEWEB)

    Busev, A I; Ignat' eva, T I; Lomakina, L N [Moskovskij Gosudarstvennyj Univ. (USSR). Kafedra Analiticheskoj Khimii

    1975-05-01

    Interaction of ruthenium (4) and osmium (4) with 2-mercaptobenzimidazole (2MBI), 2-mercaptobenzoxazole (2MBO) and 2-mercaptobenzothiazole (2MBT) in the presence of EDTA was studied. The interaction of ruthenium (4) and osmium (4) with EDTA was considered. Ruthenium complex is formed with constant output at 2-4.5 pH after 30 min. heating. In the low acid solution (pH 2-4) osmium reacts with EDTA forming soluble compound. Characteristics of ruthenium (4) compound with 2MBI, 2MBO and 2MBT produced in the presence of EDTA are presented. Osmium (4) in the presence of EDTA and above mentioned organic reagents and when heating forms low soluble compounds. Possibility of joint determination of ruthenium and osmium with help of 2MBI in the presence of EDTA under conditions of minimum complexing osmium with EDTA was investigated.

  2. Radiometric titration of thallium(III) with EDTA

    International Nuclear Information System (INIS)

    Rao, V.R.S.; Pulla Rao, Ch.; Tataiah, G.

    1978-01-01

    Radioactive solutions containing very small amounts of thallium(III) can be determined by radiometric titration using ammonia as hydrolysing agent. Aqueous solution of thallium(I) (both inactive and radioactive) is treated with bromine water till the appearance of the brown colour of bromine, and the solution is warmed to 80 deg C to expel the excess bromine. By this procedure all thallium(I) is quantitatively oxidised to thallium(III). An aqueous solution of ammonia is added to precipitate thallium(III) as thallic oxide. It is then filtered, washed with water to free it from bromide and then dissolved in 2N HCl and the solution is then standardised. 2 ml of this solution is transferred to a 20 ml volumetric flask, 1 ml of radioactive thallium(III) solution to be standardised is added as well as incremental amounts of EDTA solution and mixed thoroughly. Uncomplexed thallium(III) is then precipitated by the addition of an ammonia solution and diluted to 20 ml. Required amount of this mixture is centrifuged. The beta activity of the supernatant aliquot is measured using a GM counter. Quantitative determination of Tl(III) in the range of 1-10 μM can be carried out. The interference of cations such as Au(III), iron(III), Ga(III) can be eliminated by pretreatment of the Tl(III) solution before carrying out radiometric titration. The results obtained are reproducible and accurate to +-3%. (T.I.)

  3. Buffer erosion in dilute groundwater

    International Nuclear Information System (INIS)

    Schatz, T.; Kanerva, N.; Martikainen, J.; Sane, P.; Olin, M.; Seppaelae, A.; Koskinen, K.

    2013-08-01

    One scenario of interest for repository safety assessment involves the loss of bentonite buffer material in contact with dilute groundwater flowing through a transmissive fracture interface. In order to examine the extrusion/erosion behavior of bentonite buffer material under such circumstances, a series of experiments were performed in a flow-through, 1 mm aperture, artificial fracture system. These experiments covered a range of solution chemistry (salt concentration and composition), material composition (sodium montmorillonite and admixtures with calcium montmorillonite), and flow velocity conditions. No erosion was observed for sodium montmorillonite against solution compositions from 0.5 g/L to 10 g/L NaCl. No erosion was observed for 50/50 calcium/sodium montmorillonite against 0.5 g/L NaCl. Erosion was observed for both sodium montmorillonite and 50/50 calcium/sodium montmorillonite against solution compositions ≤ 0.25 g/L NaCl. The calculated erosion rates for the tests with the highest levels of measured erosion, i.e., the tests run under the most dilute conditions (ionic strength (IS) < ∼1 mM), were well-correlated to flow velocity, whereas the calculated erosion rates for the tests with lower levels of measured erosion, i.e., the tests run under somewhat less dilute conditions (∼1 mM < IS < ∼4 mM), were not similarly correlated indicating that material and solution composition can significantly affect erosion rates. In every experiment, both erosive and non-erosive, emplaced buffer material extruded into the fracture and was observed to be impermeable to water flowing in the fracture effectively forming an extended diffusive barrier around the intersecting fracture/buffer interface. Additionally, a model which was developed previously to predict the rate of erosion of bentonite buffer material in low ionic strength water in rock fracture environments was applied to three different cases: sodium montmorillonite expansion in a vertical tube, a

  4. BUFFER CAPACITY IN HETEROGENEOUS MULTICOMPONENT SYSTEMS. REVIEW

    Directory of Open Access Journals (Sweden)

    Oxana Spinu

    2015-12-01

    Full Text Available The quantitative basis of the theory of buffer properties for two-phase acid-base buffer systems and for multicomponent heterogeneous systems has been derived. The analytical equations with respect to all components for diverse multicomponent systems were deduced. It has been established, that the buffer capacities of components are mutually proportional.

  5. Doped LZO buffer layers for laminated conductors

    Science.gov (United States)

    Paranthaman, Mariappan Parans [Knoxville, TN; Schoop, Urs [Westborough, MA; Goyal, Amit [Knoxville, TN; Thieme, Cornelis Leo Hans [Westborough, MA; Verebelyi, Darren T [Oxford, MA; Rupich, Martin W [Framingham, MA

    2010-03-23

    A laminated conductor includes a metallic substrate having a surface, a biaxially textured buffer layer supported by the surface of the substrate, the biaxially textured buffer layer comprising LZO and a dopant for mitigating metal diffusion through the LZO, and a biaxially textured conductor layer supported by the biaxially textured buffer layer.

  6. RESEARCH NEEDS IN RIPARIAN BUFFER RESTORATION

    Science.gov (United States)

    Riparian buffer restorations are used as management tools to produce favorable water quality impacts; moreover, the basis for riparian buffers as an instrument of water quality restoration rests on a relatively firm foundation. However, the extent to which buffers can restore rip...

  7. Molecular characterization of microbial population dynamics during sildenafil citrate degradation.

    Science.gov (United States)

    De Felice, Bruna; Argenziano, Carolina; Guida, Marco; Trifuoggi, Marco; Russo, Francesca; Condorelli, Valerio; Inglese, Mafalda

    2009-02-01

    Little is known about pharmaceutical and personal care products pollutants (PPCPs), but there is a growing interest in how they might impact the environment and microbial communities. The widespread use of Viagra (sildenafil citrate) has attracted great attention because of the high usage rate, the unpredictable disposal and the unknown potential effects on wildlife and the environment. Until now information regarding the impact of Viagra on microbial community in water environment has not been reported. In this research, for the first time, the genetic profile of the microbial community, developing in a Viagra polluted water environment, was evaluated by means of the 16S and 18S rRNA genes, for bacteria and fungi, respectively, amplified by polymerase chain reaction (PCR) and separated using the denaturing gradient gel electrophoresis (DGGE) technique. The DGGE results revealed a complex microbial community structure with most of the population persisting throughout the experimental period. DNA sequences from bands observed in the different denaturing gradient gel electrophoresis profiles exhibited the highest degree of identity to uncultured bacteria and fungi found previously mainly in polluted environmental and treating bioreactors. Biotransformation ability of sildenafil citrate by the microbial pool was studied and the capability of these microorganisms to detoxify a polluted water ecosystem was assessed. The bacterial and fungal population was able to degrade sildenafil citrate entirely. Additionally, assays conducted on Daphnia magna, algal growth inhibition assay and cell viability determination on HepG2 human cells showed that biotransformation products obtained from the bacterial growth was not toxic. The higher removal efficiency for sildenafil citrate and the lack of toxicity by the biotransformation products obtained showed that the microbial community identified here represented a composite population that might have biotechnological relevance to

  8. Effect of EDTA on luminescence property of Eu+3 doped YPO4 nanoparticles

    International Nuclear Information System (INIS)

    Parchur, A.K.; Okram, G.S.; Singh, R.A.; Tewari, R.; Pradhan, Lina; Vatsa, R.K.; Ningthoujan, R.S.

    2010-01-01

    Nanoparticles of Eu 3+ doped YPO 4 have been prepared using ethylene glycol (EG). Ethylene diamine tetra acetic acid (EDTA) is used as a complexing agent. X-ray diffraction results show that the nanoparticles are crystalline in tetragonal structure. Based on William-Hall relation, the effective crystallite size and strain developed in lattice are found to be 28 nm and 0.002, respectively. With the addition of EDTA, there is a slight shift towards the lower wavelength in emission peaks. Asymmetric ratio of electric to magnetic dipole transition intensities are found to decrease with addition of EDTA. Emission intensity decreases with EDTA because of decrease of particle size as well as decrease of number of Eu 3+ activators per unit volume. These materials are dispersible in water, which may have potential biological applications. (author)

  9. Effect Of EDTA On Luminescence Property Of Eu+3 Doped YPO4 Nanoparticles

    International Nuclear Information System (INIS)

    Parchur, A. K.; Okram, G. S.; Singh, R. A.; Tewari, R.; Pradhan, Lina; Vatsa, R. K.; Ningthoujam, R. S.

    2010-01-01

    Nanoparticles of Eu 3+ doped YPO 4 have been prepared using ethylene glycol (EG). Ethylene diamine tetra acetic acid (EDTA) is used as a complexing agent. X-ray diffraction results show that the nanoparticles are crystalline in tetragonal structure. Based on William-Hall relation, the effective crystallite size and strain developed in lattice are found to be 28 nm and 0.002, respectively. With the addition of EDTA, there is a slight shift towards the lower wavelength in emission peaks. Asymmetric ratio of electric to magnetic dipole transition intensities are found to decrease with addition of EDTA. Emission intensity decreases with EDTA because of decrease of particle size as well as decrease of number of Eu 3+ activators per unit volume. These materials are dispersible in water, which may have potential biological applications.

  10. 51Cr-EDTA plasma clearance in severe renal failure determined by one plasma sample

    DEFF Research Database (Denmark)

    Kamper, A L; Nielsen, S L

    1989-01-01

    Two hundred and thirty-four measurements of standard 51Cr-EDTA plasma clearance were made in 50 patients with severe chronic renal failure. Based on these data two calculation methods were attempted using one plasma sample drawn 24 h after injection of 51Cr-EDTA. One of the methods used the 'one...... at zero-time was derived from injected dose and body surface area. This method might provide values 1.5 ml/min below or 0.8 ml/min above the established method of 51Cr-EDTA plasma clearance, which would be acceptable for clinical purposes. It is concluded that exact plasma clearance of 51Cr-EDTA in severe...... renal dysfunction (estimated clearance values below 21 ml/min) may be determined with adequate precision by one plasma sample drawn at 24 h after injection of the tracer without sampling at 5 h. This appears to be a very practical simplification....

  11. Formation of nitridotechnetium(VI) μ-oxo dimer complexes with EDTA and EDDA

    International Nuclear Information System (INIS)

    Takayama, T.; Kani, Y.; Sekine, T.; Kudo, H.; Yoshihara, K.

    1995-01-01

    Reactions of [ 99 TcNCl 4 ] - with ethylenediaminetetraacetic acid 4 (ETDA) and ethylenediamine-N,N'-diacetic acid (EDDA) in a mixture of water and acetone gave Tc VI N-EDTA and Tc VI N-EDTA complexes. The infrared spectra of both reaction products showed the existence of the Tc≡N and C=O groups. The elemental analysis indicated the 1:1 TcN-ligand ratio in the EDTA and EDDA complexes. Electrophoresis showed that the Tc VI -EDTA complex was an anionic species in a perchlorate solution. For the Tc VI N-EDDA complex, neutral and anionic species were formed, depending on the pH of the solution. Formation of the μ-oxo dimer complexes was suggested from the UV-Vis absorption spectra. (author) 11 refs.; 4 figs.; 1 tab

  12. Production and characterization of monoclonal antibodies to the edta extract of Leptospira interrogans, serovar icterohaemorrhagiae

    Directory of Open Access Journals (Sweden)

    Lilian Terezinha de Queiroz Leite

    1996-10-01

    Full Text Available Monoclonal antibodies (MABs ivere produced against an etbylenediaminetetraacetate (EDTA extract of Leptospira interrogans serovar icterohaemorrhagiae being characterized by gel precipitation as IgM and IgG (IgGl and IgG2b. The EDTA extract was detected as several bands by silver staining in SDS-PAGE. In the Western blot the bands around 20 KDa reacted with a monoclonal antibody, 47B4D6, and was oxidized by periodate and was not digested by pronase, suggesting that the determinant is of carbohydrate nature, lmmunocytochemistry, using colloidal gold labeling, showed that an EDTA extract determinant recognized by monoclonal antibody 47B4D6, is localized under the outer envelope of serovar icterohaemorrhagiae. Hoe AIAB raised against the EDTA extract was not able to protect hamsters from lethal challenge with virulent homologous leptospires.

  13. Zinc species distribution in EDTA-extract residues of zinc-contaminated soil

    International Nuclear Information System (INIS)

    Chang, S.-H.; Wei, Y.-L.; Wang, H. Paul

    2007-01-01

    Soil sample from a site heavily contaminated with >10 wt.% zinc is sampled and extracted with aqueous solutions of ethylene diamine tetra-acetic acid (EDTA) that is a reagent frequently used to extract heavy metals in soil remediation. Three liquid/soil ratios (5/1, 20/1, and 100/1) were used in the extracting experiment. The molecular environment of the residual Zn in the EDTA-extract residues of zinc-contaminated soil is investigated with XANES technique. The results indicate that EDTA does not show considerable preference of chelating for any particular Zn species during the extraction. Zn species distribution in the sampled soil is found to resemble that in all EDTA-extract residues; Zn(OH) 2 is determined as the major zinc species (60-70%), seconded by organic zinc (21-26%) and zinc oxide (9-14%)

  14. Late calcium EDTA rescues hippocampal CA1 neurons from global ischemia-induced death.

    Science.gov (United States)

    Calderone, Agata; Jover, Teresa; Mashiko, Toshihiro; Noh, Kyung-min; Tanaka, Hidenobu; Bennett, Michael V L; Zukin, R Suzanne

    2004-11-03

    Transient global ischemia induces a delayed rise in intracellular Zn2+, which may be mediated via glutamate receptor 2 (GluR2)-lacking AMPA receptors (AMPARs), and selective, delayed death of hippocampal CA1 neurons. The molecular mechanisms underlying Zn2+ toxicity in vivo are not well delineated. Here we show the striking finding that intraventricular injection of the high-affinity Zn2+ chelator calcium EDTA (CaEDTA) at 30 min before ischemia (early CaEDTA) or at 48-60 hr (late CaEDTA), but not 3-6 hr, after ischemia, afforded robust protection of CA1 neurons in approximately 50% (late CaEDTA) to 75% (early CaEDTA) of animals. We also show that Zn2+ acts via temporally distinct mechanisms to promote neuronal death. Early CaEDTA attenuated ischemia-induced GluR2 mRNA and protein downregulation (and, by inference, formation of Zn2+-permeable AMPARs), the delayed rise in Zn2+, and neuronal death. These findings suggest that Zn2+ acts at step(s) upstream from GluR2 gene downregulation and implicate Zn2+ in transcriptional regulation and/or GluR2 mRNA stability. Early CaEDTA also blocked mitochondrial release of cytochrome c and Smac/DIABLO (second mitochondria-derived activator of caspases/direct inhibitor of apoptosis protein-binding protein with low pI), caspase-3 activity (but not procaspase-3 cleavage), p75NTR induction, and DNA fragmentation. These findings indicate that CaEDTA preserves the functional integrity of the mitochondrial outer membrane and arrests the caspase death cascade. Late injection of CaEDTA at a time when GluR2 is downregulated and caspase is activated inhibited the delayed rise in Zn2+, p75NTR induction, DNA fragmentation, and cell death. The finding of neuroprotection by late CaEDTA administration has striking implications for intervention in the delayed neuronal death associated with global ischemia.

  15. Determination of vanadium(V) by direct automatic potentiometric titration with EDTA using a chemically modified electrode as a potentiometric sensor.

    Science.gov (United States)

    Quintar, S E; Santagata, J P; Cortinez, V A

    2005-10-15

    A chemically modified electrode (CME) was prepared and studied as a potentiometric sensor for the end-point detection in the automatic titration of vanadium(V) with EDTA. The CME was constructed with a paste prepared by mixing spectral-grade graphite powder, Nujol oil and N-2-naphthoyl-N-p-tolylhydroxamic acid (NTHA). Buffer systems, pH effects and the concentration range were studied. Interference ions were separated by applying a liquid-liquid extraction procedure. The CME did not require any special conditioning before using. The electrode was constructed with very inexpensive materials and was easily made. It could be continuously used, at least two months without removing the paste. Automatic potentiometric titration curves were obtained for V(V) within 5 x 10(-5) to 2 x 10(-3)M with acceptable accuracy and precision. The developed method was applied to V(V) determination in alloys for hip prosthesis.

  16. SERS substrates fabricated using ceramic filters for the detection of bacteria: Eliminating the citrate interference

    Science.gov (United States)

    Mosier-Boss, P. A.; Sorensen, K. C.; George, R. D.; Sims, P. C.; O'braztsova, A.

    2017-06-01

    It was found that spectra obtained for bacteria on SERS substrates fabricated by filtering citrate-generated Ag nanoparticles (NPs) onto rigid, ceramic filters exhibited peaks due to citrate as well as the bacteria. In many cases the citrate spectrum overwhelmed that of the bacteria. Given the simplicity of the method to prepare these substrates, means of eliminating this citrate interference were explored. It was found that allowing a mixture of bacteria suspension and citrate-generated Ag NPs to incubate prior to filtering onto the ceramic filter eliminated this interference.

  17. Potentiometric determination of sulfate with EDTA and the cupric-selective electrode

    International Nuclear Information System (INIS)

    Baumann, E.W.

    1976-11-01

    Sulfate was indirectly determined by precipitating sulfate as BaSO 4 and then dissolving BaSO 4 in excess ammoniacal EDTA. The excess EDTA was titrated potentiometrically with La 3+ . A cupric-selective electrode was used to detect the end point. About 10 -3 M SO 4 2- was determined in 3M HCl solutions of metal oxides with a relative standard deviation of 3.5 percent and a bias of +4 percent

  18. Effects of Na2CaEDTA on lead deposits in rabbit osseous tissue

    International Nuclear Information System (INIS)

    Doniec, J.; Trojanowska, B.; Trzcinka-Ochocka, M.; Garlicka, I.

    1983-01-01

    Radiochemical and autoradiographic methods were used for 210 Pb determination after Na 2 CaEDTA administration to rabbits. 210 Pb was determined in soft tissues, compact and trabecular bones and growing microareas on the endosteum of the long bone. After Na 2 CaEDTA injection lead was depleted from 'new' deposits mainly on the growing surface of both trabecular and compact bones. (Auth.)

  19. Influence of EDTA on lead transportation and accumulation by Sedum alfredii Hance

    Energy Technology Data Exchange (ETDEWEB)

    Liu Dan [Zhejiang Univ., Hangzhou (China). Key Lab. of Environmental Remediation and Ecosystem Health, Ministry of Education; Zhejiang Forestry College, Lin' an (China). School of Tourism and Health; Li Ting-Qiang; Yang Xiao-E; Islam, E.; Jin Xiao-Fen; Mahmood, Q. [Zhejiang Univ., Hangzhou (China). Key Lab. of Environmental Remediation and Ecosystem Health, Ministry of Education

    2007-09-15

    Hydroponics and pot experiments were conducted to study the effects of ethylenediaminetetraacetic acid (EDTA) on Pb transportation and accumulation by two contrasting ecotypes of Sedum alfredii Hance. In hydroponics experiments, the accumulating ecotype (AE) showed more ability to tolerate Pb toxicitycompared with the non-accumulating ecotype (NAE). When treated with equimolar mixtures of EDTA and Pb, maximum Pb accumulation occurred without any phytotoxicity symptoms. Pot experiments with Pb contents of 400 mg kg{sup -1} showed that 5 mm EDTA is the optimum dose for the phytoextraction of soils contaminated with relatively low Pb levels; in contrast, increasing EDTA addition resulted in increased Pb accumulation in the shoots of AE in soils with high Pb content (1200 mg kg{sup -1}). The post-harvest effects of EDTA on available Pb were strong compared with those without addition of EDTA (CK). Within the initial 7 days almost no differences of water-soluble Pb were noted in soils contaminated with both levels of Pb but after 2 weeks, water-soluble Pb started to decrease significantlycompared with before. Considering the toxicity and biodegradability of synthetic chelators, it can be concluded that the chelate-assisted technique is more suitable for soils contaminated with low Pb levels and to avoid environment risks; a suitable dose of chelators must be considered before application. (orig.)

  20. EDTA treatment alters protein glycosylation in the cellular slime mold Dictyostelium discoideum

    International Nuclear Information System (INIS)

    West, C.M.; Brownstein, S.A.

    1988-01-01

    The authors have found that treatment of cells with EDTA resulted in the accumulation of lower molecular weight forms of two cell-type-specific glycoproteins. These new glycoproteins lacked a developmentally regulated glycoantigen defined by monoclonal antibody 54.2. Since EDTA dissociated the cells, the possible involvement of cell separation was tested by immobilizing cells in soft agarose. Glycoantigen expression on these proteins was found to be dependent on cAMP and high oxygen tension but not on cell contact, and was reversibly sensitive to EDTA regardless of the state of cell association. The EDTA effect was mimicked by other soluble, but not particulate, membrane impermeable chelators, could be completed by Zn 2+ better than Mg 2+ , and appeared to involve an intracellular mechanism. Studies with [ 14 C]EDTA showed that EDTA equilibrated with a cellular compartment in a temperature-dependent, Zn 2+ -insensitive fashion with half-time kinetics of loading and unloading of 30-40 min. The data suggest that this step in glycosylation, which was found to be delayed 1 or more hours subsequent to protein synthesis, involves an intracellular, transition metal-ion-dependent process which can be modulated by chelators entering the cell through the endocytic pathway

  1. Effect of NaFeEDTA-fortified soy sauce on zinc absorption in children.

    Science.gov (United States)

    Li, Min; Wu, Jinghuan; Ren, Tongxiang; Wang, Rui; Li, Weidong; Piao, Jianhua; Wang, Jun; Yang, Xiaoguang

    2015-03-01

    NaFeEDTA has been applied in many foods as an iron fortificant and is used to prevent iron deficiency in Fe-depleted populations. In China, soy sauce is fortified with NaFeEDTA to control iron deficiency. However, it is unclear whether Fe-fortified soy sauce affects zinc absorption. To investigate whether NaFeEDTA-fortified soy sauce affects zinc absorption in children, sixty children were enrolled in this study and randomly assigned to three groups (10 male children and 10 female children in each group). All children received daily 3 mg of (67)Zn and 1.2 mg of dysprosium orally, while the children in the three groups were supplemented with NaFeEDTA-fortified soy sauce (6 mg Fe, NaFeEDTA group), FeSO₄-fortified soy sauce (6 mg Fe, FeSO₄ group), and no iron-fortified soy sauce (control group), respectively. Fecal samples were collected during the experimental period and analyzed for the Zn content, (67)Zn isotope ratio and dysprosium content. The Fe intake from NaFeEDTA-fortified and FeSO₄-fortified groups was significantly higher than that in the control group (P sauce does not affect Zn bioavailability in children.

  2. Enhanced degradation of 4-nitrophenol by microwave assisted Fe/EDTA process

    Energy Technology Data Exchange (ETDEWEB)

    Liu Bo, E-mail: yongboliu@163.com [State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210093 (China); Li Song, E-mail: ls8214@163.com [State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210093 (China); Zhao Yongjun, E-mail: zyjun2007@126.com [State Key Laboratory of Pollution Control and Resource Reuse, School of Life Science, Nanjing University, Nanjing 210093 (China); Wu Wenfei, E-mail: feibanana6@163.com [State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210093 (China); Zhang Xuxiang, E-mail: zhangxx@nju.edu.cn [State Key Laboratory of Pollution Control and Resource Reuse, School of Life Science, Nanjing University, Nanjing 210093 (China); Gu Xueyuan, E-mail: xygu@nju.edu.cn [State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210093 (China); Li Ruihua, E-mail: liruihua@nju.edu.cn [State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210093 (China); Yang Shaogui, E-mail: ysg420@sina.com [State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210093 (China)

    2010-04-15

    A microwave assisted zero-valent iron oxidation process was studied in order to investigate the synergetic effects of MW irradiation on Fe/EDTA system (Fe/EDTA/MW) treated 4-nitrophenol (4-NP) from aqueous solution. The results indicated that the thermal effect of microwave improved the removal effect of 4-NP and TOC through raising the temperature of the system, as well as the non-thermal effect generated by the interaction between the microwave and the Fe resulting in an increase in the hydrophobic character of Fe surface. During the degradation of 4-NP in Fe/EDTA/MW system, the optimum value for MW power, Fe, EDTA dosage was 400 W, 2 g and 0.4 mM, respectively. The possible pathway for degrading the 4-NP was proposed based on GC/MS and HPLC analysis of the degradation intermediates. The concentration change course of the main bio-refractory by-products, the aminophenol formed in the degradation of 4-NP suggested a more efficient degradation and mineralization in Fe/EDTA/MW system. Finally, BOD{sub 5}/COD{sub Cr} of the solution increased from 0.237 to 0.635 after reaction for 18 min, indicating that the biodegradability of wastewater was greatly improved by Fe/EDTA/MW system and would benefit to further treatment by biochemical methods.

  3. Enhanced degradation of 4-nitrophenol by microwave assisted Fe/EDTA process

    International Nuclear Information System (INIS)

    Liu Bo; Li Song; Zhao Yongjun; Wu Wenfei; Zhang Xuxiang; Gu Xueyuan; Li Ruihua; Yang Shaogui

    2010-01-01

    A microwave assisted zero-valent iron oxidation process was studied in order to investigate the synergetic effects of MW irradiation on Fe/EDTA system (Fe/EDTA/MW) treated 4-nitrophenol (4-NP) from aqueous solution. The results indicated that the thermal effect of microwave improved the removal effect of 4-NP and TOC through raising the temperature of the system, as well as the non-thermal effect generated by the interaction between the microwave and the Fe resulting in an increase in the hydrophobic character of Fe surface. During the degradation of 4-NP in Fe/EDTA/MW system, the optimum value for MW power, Fe, EDTA dosage was 400 W, 2 g and 0.4 mM, respectively. The possible pathway for degrading the 4-NP was proposed based on GC/MS and HPLC analysis of the degradation intermediates. The concentration change course of the main bio-refractory by-products, the aminophenol formed in the degradation of 4-NP suggested a more efficient degradation and mineralization in Fe/EDTA/MW system. Finally, BOD 5 /COD Cr of the solution increased from 0.237 to 0.635 after reaction for 18 min, indicating that the biodegradability of wastewater was greatly improved by Fe/EDTA/MW system and would benefit to further treatment by biochemical methods.

  4. Electrochemical Oxidation of EDTA in Nuclear Wastewater Using Platinum Supported on Activated Carbon Fibers

    Science.gov (United States)

    Zhao, Bo; Zhu, Wenkun; Mu, Tao; Hu, Zuowen; Duan, Tao

    2017-01-01

    A novel Pt/ACF (Pt supported on activated carbon fibers) electrode was successfully prepared with impregnation and electrodeposition method. Characterization of the electrodes indicated that the Pt/ACF electrode had a larger effective area and more active sites. Electrochemical degradation of ethylenediaminetetra-acetic acid (EDTA) in aqueous solution with Pt/ACF electrodes was investigated. The results showed that the 3% Pt/ACF electrode had a better effect on EDTA removal. The operational parameters influencing the electrochemical degradation of EDTA with 3% Pt/ACF electrode were optimized and the optimal removal of EDTA and chemical oxygen demand (COD) were 94% and 60% after 100 min on condition of the electrolyte concentration, initial concentration of EDTA, current density and initial value of pH were 0.1 mol/L, 300 mg/L, 40 mA/cm2 and 5.0, respectively. The degradation intermediates of EDTA in electrochemical oxidation with 3% Pt/ACF electrode were identified by gas chromatography-mass spectrum (GC-MS). PMID:28754016

  5. Electrochemical Oxidation of EDTA in Nuclear Wastewater Using Platinum Supported on Activated Carbon Fibers.

    Science.gov (United States)

    Zhao, Bo; Zhu, Wenkun; Mu, Tao; Hu, Zuowen; Duan, Tao

    2017-07-21

    A novel Pt/ACF (Pt supported on activated carbon fibers) electrode was successfully prepared with impregnation and electrodeposition method. Characterization of the electrodes indicated that the Pt/ACF electrode had a larger effective area and more active sites. Electrochemical degradation of ethylenediaminetetra-acetic acid (EDTA) in aqueous solution with Pt/ACF electrodes was investigated. The results showed that the 3% Pt/ACF electrode had a better effect on EDTA removal. The operational parameters influencing the electrochemical degradation of EDTA with 3% Pt/ACF electrode were optimized and the optimal removal of EDTA and chemical oxygen demand (COD) were 94% and 60% after 100 min on condition of the electrolyte concentration, initial concentration of EDTA, current density and initial value of pH were 0.1 mol/L, 300 mg/L, 40 mA/cm² and 5.0, respectively. The degradation intermediates of EDTA in electrochemical oxidation with 3% Pt/ACF electrode were identified by gas chromatography-mass spectrum (GC-MS).

  6. Immunological effects of CaEDTA injection: observations in two lead workers.

    Science.gov (United States)

    Sata, F; Araki, S; Sakai, T; Nakata, A; Yamashita, K; Morita, Y; Tanigawa, T; Miki, A

    1997-12-01

    To evaluate the effects of calcium disodium ethylenediamine tetraacetate (CaEDTA) injection on human immune system in relation to exposure to lead, we administered CaEDTA by intravenous injection for 1 hr three times (three consecutive days) a week to two male lead workers. They had been engaged in recycling lead for 31 and 22 years, aged 61 and 53 years (workers 1 and 2), respectively. Before the treatment of CaEDTA, their blood lead concentrations (PbB) were 81 and 68 micrograms/dl, respectively. The administration of CaEDTA had been carried out to worker 1 for 10 weeks and to worker 2 for 6 weeks. A significant decrease in PbB between before and after three-times CaEDTA injection was found in both workers. Significant increases in IgG, IgA, IgM, CD8+, and CD57+ cells were found in worker 1. A significant increase in IgD was found in worker 2. During the study period, IgG in worker 1 and CD4+ cells in worker 2 were gradually increasing. There was a significant negative correlation between IgG and PbB in worker 1. It is suggested that the immunological function such as antibody formation in lead workers might be improved by CaEDTA injection.

  7. Improving Water Quality With Conservation Buffers

    Science.gov (United States)

    Lowrance, R.; Dabney, S.; Schultz, R.

    2003-12-01

    Conservation buffer technologies are new approaches that need wider application. In-field buffer practices work best when used in combination with other buffer types and other conservation practices. Vegetative barriers may be used in combination with edge-of-field buffers to protect and improve their function and longevity by dispersing runoff and encouraging sediment deposition upslope of the buffer. It's important to understand how buffers can be managed to help reduce nutrient transport potential for high loading of nutrients from manure land application sites, A restored riparian wetland buffer retained or removed at least 59 percent of the nitrogen and 66 percent of the phosphorus that entered from an adjacent manure land application site. The Bear Creek National Restoration Demonstration Watershed project in Iowa has been the site of riparian forest buffers and filter strips creation; constructed wetlands to capture tile flow; stream-bank bioengineering; in-stream structures; and controlling livestock grazing. We need field studies that test various widths of buffers of different plant community compositions for their efficacy in trapping surface runoff, reducing nonpoint source pollutants in subsurface waters, and enhancing the aquatic ecosystem. Research is needed to evaluate the impact of different riparian grazing strategies on channel morphology, water quality, and the fate of livestock-associated pathogens and antibiotics. Integrating riparian buffers and other conservation buffers into these models is a key objective in future model development.

  8. Aggregation and adhesion of gold nanoparticles in phosphate buffered saline

    Energy Technology Data Exchange (ETDEWEB)

    Du Shangfeng, E-mail: s.du@bham.ac.uk; Kendall, Kevin; Toloueinia, Panteha; Mehrabadi, Yasamin; Gupta, Gaurav; Newton, Jill [University of Birmingham, School of Chemical Engineering (United Kingdom)

    2012-03-15

    In applications in medicine and more specifically drug delivery, the dispersion stability of nanoparticles plays a significant role on their final performances. In this study, with the use of two laser technologies, dynamic light scattering (DLS) and nanoparticle tracking analysis (NTA), we report a simple method to estimate the stability of nanoparticles dispersed in phosphate buffered saline (PBS). Stability has two features: (1) self-aggregation as the particles tend to stick to each other; (2) disappearance of particles as they adhere to surrounding substrate surfaces such as glass, metal, or polymer. By investigating the effects of sonication treatment and surface modification by five types of surfactants, including nonylphenol ethoxylate (NP9), polyvinyl pyrrolidone (PVP), human serum albumin (HSA), sodium dodecyl sulfate (SDS) and citrate ions on the dispersion stability, the varying self-aggregation and adhesion of gold nanoparticles dispersed in PBS are demonstrated. The results showed that PVP effectively prevented aggregation, while HSA exhibited the best performance in avoiding the adhesion of gold nanoparticle in PBS onto glass and metal. The simple principle of this method makes it a high potential to be applied to other nanoparticles, including virus particles, used in dispersing and processing.

  9. Buffered Communication Analysis in Distributed Multiparty Sessions

    Science.gov (United States)

    Deniélou, Pierre-Malo; Yoshida, Nobuko

    Many communication-centred systems today rely on asynchronous messaging among distributed peers to make efficient use of parallel execution and resource access. With such asynchrony, the communication buffers can happen to grow inconsiderately over time. This paper proposes a static verification methodology based on multiparty session types which can efficiently compute the upper bounds on buffer sizes. Our analysis relies on a uniform causality audit of the entire collaboration pattern - an examination that is not always possible from each end-point type. We extend this method to design algorithms that allocate communication channels in order to optimise the memory requirements of session executions. From these analyses, we propose two refinements methods which respect buffer bounds: a global protocol refinement that automatically inserts confirmation messages to guarantee stipulated buffer sizes and a local protocol refinement to optimise asynchronous messaging without buffer overflow. Finally our work is applied to overcome a buffer overflow problem of the multi-buffering algorithm.

  10. A THEORETICAL DISCUSSION OF THE ECONOMIC EFFECTS OF BUFFER STOCKS AND BUFFER FUNDS

    OpenAIRE

    Simmons, Phil

    1988-01-01

    It has been established that the absence of risk markets justifies market intervention in principle. The form of intervention that has been discussed most widely in the literature is the buffer stock. This paper points out that other forms of intervention, specifically buffer funds, are likely to perform better. The analysis shows that buffer funds are likely to outperform buffer stocks because they address market failure more directly. A sub-theme developed in this paper is that since buffer...

  11. Colorimetric determination of sildenafil citrate (Viagra) through ion-associate complex formation.

    Science.gov (United States)

    Amin, Alaa S; Moustafa, Moustafa E; El-Dosoky, Reham

    2009-01-01

    A simple, quick, accurate, and sensitive colorimetric method is described for the determination of sildenafil citrate (SLD). The method is based on the reaction of SLD with Congo Red, Sudan II, and Gentian Violet in buffered aqueous solutions at pH 2.5, 6.5, and 11.0, respectively, to give highly colored soluble ion-associate complex species; the colored products are quantitated colorimetrically at 523, 554, and 569 nm, respectively. The various experimental conditions were optimized. The stoichiometric ratio was found to be 1:1 for all ion associates; the calculated logarithmic stability constants were 8.51, 7.79, and 5.58, respectively. Beer's law was obeyed over the concentration range of 0.2-7.0 microg/mL, whereas the Ringbom optimum concentration range was 0.4-6.5 microg/mL. Values for molar absorptivity, Sandell sensitivity, and detection and quantification limits were also calculated. The proposed method was successfully applied to the determination of SLD in Viagra tablets and in serum samples by using the technique of standard additions with mean accuracy values of 100.06 +/- 1.14, 99.87 +/- 0.70, and 99.86 +/- 0.97% for Viagra tablets and 99.88 +/- 0.60, 99.90 +/- 0.90, and 100.24 +/- 0.80% for serum samples, respectively.

  12. Effect of PDGF-BB combined with EDTA gel on adhesion and proliferation to the root surface.

    Science.gov (United States)

    Belal, Mahmoud Helmy; Watanabe, Hisashi; Ichinose, Shizuko; Ishikawa, Isao

    2012-07-01

    Periodontal regeneration using EDTA or PDGF showed promising results, but the effect of combined application was still unclear. This study aimed to verify the effect of EDTA and/or PDGF application on root adhesion and proliferation of PDL fibroblast cells. Eighty specimens were prepared from forty periodontitis teeth and made five groups: (1) diseased (untreated), (2) SRP (scaling root planing), (3) EDTA (24%), (4) PDGF (25 ng/ml) and (5) Combined application of EDTA and PDGF. Periodontal ligament cells were cultured on the above conditioned dentin plate, and SEM examination was preformed and cells were counted within a representative standard area for both cell morphology and density. All groups including untreated showed significantly increase of adhered cells from baseline to 7 days. Among them, rate of increase was much higher in EDTA, PDGF, and combined groups. ANOVA test indicated that the number of cells in PDGF and combined groups was significantly higher than diseased group at 1 day. On day 7, PDGF and combined groups showed significantly higher number of adhesion cells than that found in the diseased, SRP and EDTA groups. Thus, root conditioning with EDTA enhanced cell adhesion more than SRP alone. There was no significant difference of cell number between PDGF and combined group. Combined application of EDTA and PDGF increased significantly PDL cell adhesion than EDTA alone. PDGF alone, however, also showed comparable effect to combined application at all periods. Thus, synergistic effect between PDGF and EDTA was not observed.

  13. Enhancing phosphorus release from waste activated sludge containing ferric or aluminum phosphates by EDTA addition during anaerobic fermentation process.

    Science.gov (United States)

    Zou, Jinte; Zhang, Lili; Wang, Lin; Li, Yongmei

    2017-03-01

    The effect of ethylene diamine tetraacetic acid (EDTA) addition on phosphorus release from biosolids and phosphate precipitates during anaerobic fermentation was investigated. Meanwhile, the impact of EDTA addition on the anaerobic fermentation process was revealed. The results indicate that EDTA addition significantly enhanced the release of phosphorus from biosolids, ferric phosphate precipitate and aluminum phosphate precipitate during anaerobic fermentation, which is attributed to the complexation of metal ions and damage of cell membrane caused by EDTA. With the optimal EDTA addition of 19.5 mM (0.41 gEDTA/gSS), phosphorus release efficiency from biosolids was 82%, which was much higher than that (40%) without EDTA addition. Meanwhile, with 19.5 mM EDTA addition, almost all the phosphorus in ferric phosphate precipitate was released, while only 57% of phosphorus in aluminum phosphate precipitate was released. This indicates that phosphorus in ferric phosphate precipitate was much easier to be released than that in aluminum phosphate precipitate during anaerobic fermentation of sludge. In addition, proper EDTA addition facilitated the production of soluble total organic carbon and volatile fatty acids, as well as solid reduction during sludge fermentation, although methane production could be inhibited. Therefore, EDTA addition can be used as an alternative method for recovering phosphorus from waste activated sludge containing ferric or aluminum precipitates, as well as recovery of soluble carbon source. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Metformin-clomiphene citrate vs. clomiphene citrate alone: Polycystic ovarian syndrome

    Directory of Open Access Journals (Sweden)

    Aqueela Ayaz

    2013-01-01

    Full Text Available Background: Polycystic ovary syndrome (PCOS is the commonest endocrinopathy in women that is associated with reproductive and metabolic disorders. Objectives: We compared the ovulation and conception rates after the treatment with clomiphene citrate (CC alone and in combination with metformin in infertile patients presented with polycystic ovarian syndrome (PCOS. Materials and Methods: This randomized controlled trial of independent cases and controls was conducted at the Department of Obstetrics and Gynecology, Hera General Hospital, Makkah, Saudi Arabia from February 01 to December 31, 2008. The 42 subjects diagnosed as PCOS were divided into group A and B (21 subjects in each for management with CC + metformin and CC alone, respectively. Group A received 500 mg three times a day of metformin continuously from the first cycle for 6 months or till pregnancy was confirmed. In both groups CC was started at a dose of 50 mg from day-2 till day-6 of the menstrual cycle. The dose of CC was increased to 100 mg in second and 150 mg in third cycle, and then remained 150 mg for the remaining three cycles. With ovulation the dose of CC was unaltered in both groups. Data were analyzed using Statistical Package for the Social Sciences (SPSS version 16. Results: More than 50% females in both groups were had body mass index > 25. Group A achieved high rate of regular cycles, ovulation success, and conception than group B (71.4% vs. 38.1%; P = 0.03, (76.2% vs. 38.1%; P = 0.021, and (66.6% vs. 28.6%; P = 0.01, respectively. Conclusion: Management with metformin + CC increased the ovulation and conception rates.

  15. Buffered Electrochemical Polishing of Niobium

    Energy Technology Data Exchange (ETDEWEB)

    Ciovati, Gianluigi [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Tian, Hui [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); College of William and Mary, Williamsburg, VA (United States); Corcoran, Sean [Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States)

    2011-03-01

    The standard preparation of superconducting radio-frequency (SRF) cavities made of pure niobium include the removal of a 'damaged' surface layer, by buffered chemical polishing (BCP) or electropolishing (EP), after the cavities are formed. The performance of the cavities is characterized by a sharp degradation of the quality factor when the surface magnetic field exceeds about 90 mT, a phenomenon referred to as 'Q-drop.' In cavities made of polycrystalline fine grain (ASTM 5) niobium, the Q-drop can be significantly reduced by a low-temperature (? 120 °C) 'in-situ' baking of the cavity if the chemical treatment was EP rather than BCP. As part of the effort to understand this phenomenon, we investigated the effect of introducing a polarization potential during buffered chemical polishing, creating a process which is between the standard BCP and EP. While preliminary results on the application of this process to Nb cavities have been previously reported, in this contribution we focus on the characterization of this novel electrochemical process by measuring polarization curves, etching rates, surface finish, electrochemical impedance and the effects of temperature and electrolyte composition. In particular, it is shown that the anodic potential of Nb during BCP reduces the etching rate and improves the surface finish.

  16. Effectiveness of EDTA and EDTA-T brushingm on the removal of root surface smear layer Efeito do EDTA e EDTA-T aplicado de forma ativa na remoção de "smear layer" de superfícies radiculares

    Directory of Open Access Journals (Sweden)

    José Eduardo Cezar Sampaio

    2003-12-01

    Full Text Available The purpose of this study was to compare the removal of root surface smear layer following active application of EDTA gel and EDTA-T (texapon gel in different concentrations (5%, 10%, 15%, 20% and 24%, using scanning electron microscopy. A total of 220 dentin blocks obtained from the root surfaces of extracted teeth were divided into 3 groups: Group I - (control application of saline solution (n = 20; Group II - EDTA gel (pH 7.0 was applied in the following concentrations: 5%, 10%, 15%, 20% and 24% (n = 100; Group III - EDTA-T gel (pH 7.0 applied in the same concentrations described above (n = 100. The photomicrographs were evaluated by one calibrated examiner using a smear layer removal index and following statistical analysis (Kruskal-Wallis test. The results demonstrated that the specimens treated with EDTA and EDTA-T gel presented a better smear layer removal than the control group (p 0.05. Within the limits of this study, it can be concluded that all treatment modalities effectively removed the smear layer from the root surface. The addition of texapon into the EDTA gel formulation did not increase its effectiveness.O objetivo do presente estudo foi comparar, através de microscopia eletrônica de varredura, o efeito da aplicação de gel de EDTA e de EDTA-T (texapon em diferentes concentrações (5%, 10%, 15%, 20% e 24% na remoção de "smear layer" de superfícies radiculares previamente raspadas com instrumentos manuais. Duzentos e vinte espécimes de superfícies radiculares submetidas à raspagem foram divididos em 3 grupos. Grupo I - (controle solução salina (n = 20; Grupo II - gel de EDTA (pH 7,0 nas concentrações de 5%, 10%, 15%, 20% e 24% (n = 100; Grupo III - gel de EDTA-T (pH 7,0 nas concentrações acima descritas (n = 100. As fotomicrografias obtidas foram avaliadas por um examinador calibrado através da aplicação de um índice de remoção de "smear layer", e os dados foram analisados através de análise estat

  17. Evaluation of oral abdominal contrast agent containing ferric ammonium citrate

    International Nuclear Information System (INIS)

    Shiga, Toshiko; Kawamura, Yasutaka; Iwasaki, Toshiko

    1991-01-01

    We evaluated the effectiveness of oral MRI contrast agent containing ferric ammonium citrate. Twenty patients were arbitrarily divided into 2 groups according to the given dose of 100 and 200 mg Fe of oral MRI contrast agent. MRI was performed before and immediately after ingesting 300 ml solution of oral MRI contrast agent using a 1.5 T superconducting system (GE: Signa). Each dose of 100 and 200 mg Fe of oral MRI contrast agent produced sufficient enhancement of gastrointestinal tract, enough to make clear the pancreatic contour and porta hepatis. There was no significant change in blood and urine analysis observed after taking oral MRI contrast agent. The use of ferric ammonium citrate as an oral MRI contrast agent seems to add valuable information in performing upper abdominal MRI imaging. (author)

  18. Renal Localization of {sup 67}Ga Citrate in Noninfectious Nephritis

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Kang Wook; Jeong, Min Soo; Rhee, Sunn Kgoo; Kim, Sam Yong; Shin, Young Tai; Ro, Heung Kyu [Chungnam University College of Medicine, Deajeon (Korea, Republic of)

    1992-07-15

    {sup 67}Ga citrate scan has been requested for detection or follow-up of inflammatory or neoplastic disease. Visualization of {sup 67}Ga citrate in the kidneys at 48 and 72 hr post injection is usually interpreted as evidence of renal pathology. But precise mechanisms of abnormal {sup 67}Ga uptake in kidneys were unknown. We undertook a study to determine the clinical value of {sup 67}Ga citrate imaging of the kidneys in 68 patients with primary or secondary nephropathy confirmed by renal biopsy and 66 control patients without renal disease. Renal uptake in 48 to 72 hr images was graded as follows: Grade 0=background activity;1=faint uptake greater than background; 2=definite uptake, but less than lumbar vertebrae;3 same uptake as lumbar vertebrae, but less than liver; 4=same or higher uptake than liver. The results were as follows. 1) 42 of 68(62%) patients with noninfectious nephritis showed grade 2 or higher {sup 67}Ga renal uptake but only 10 percent of control patients showed similar uptake. 2) In 14 patients with systemic lupus erythematosus, 8 of 9 (89%) patients with lupus nephritis exhibited marked renal uptake. 3) 36 of 41 patients (88%) with combined nephrotic syndrome showed Grade 2 or higher renal uptake. 4) Renal {sup 67}Ga uptake was correlated with clinical severity of nephrotic syndrome determined by serum albumin level, 24 hr urine protein excretion and serum lipid levels. 5) After complete remission of nephrotic syndrome, renal uptake in all 8 patients who were initially Grade 3 or 4, decreased to Grade 1 or 0. In conclusion, we think that the mechanism of renal {sup 67}Ga uptake in nephrotic syndrome might be related to the pathogenesis of nephrotic syndrome. In systemic lupus erythematosus, {sup 67}Ga citrate scan is useful in predicting renal involvement.

  19. Colon transit scintigraphy by 67 Ga citrate for idiopathic constitution

    International Nuclear Information System (INIS)

    Neshandar Asll, I.; Ehsani, M.J.; Javadi, H.

    2005-01-01

    Background/objective: segmental colonic transit studies are important in patients with severe constipation. This study is the first Iranian preliminary survey of colonic transit scintigraphy using 67 Ga -citrate as a new method in constipated patients with normal radiographic and colonoscopic evaluations. Patients and methods: thirteen patients with idiopathic constipation underwent colon transit scintigraphy. After oral administration of 6-7 MBq Ga-citrates, serial abdominal images were taken up to 72 hours. Pattern classification wa s performed visually according to the distribution of radioactivity, Scintigraphic parameters such as geometric mean center of seq mental retention of tracer, as well as mean ac activity profiles and colonic tracer half-clearance time were calculated Results: Three patterns of colonic transit scintigraphy were recognized. Nine patients had the normal pattern, i.e. excellent propagation of ac activity. Three patients had the colonic inertia pattern with marked retention of activity in the transverse colon and splenic flexure at 48 hours, One patient had significant retention of activity in the recto sigmoid at 72 hours, defined as functional recto sigmoid obstruction . No significant difference was seen in GMC24h between the normal pattern and colonic inertia (P4.053), but GMC48h and GMC72h markedly differed between the two groups (P50.0 16 and 0.025 respectively). 'The mean half clearance time of the two groups was di different (P4.017). Our results are well compatible with scintigraphic diagnostic criteria in different patterns of colonic transit defined by other studies with different radiotracer. Conclusion: oral 67 Ga -citrate colon transit scintigraphy is a feasible method to evaluate idiopathic constipation and seems to be a suitable surrogate for radio-opaque markers. Keywords: oral 67 Ga -citrate, colonic transit study, idiopathic constipation, scintigraphy

  20. Renal Localization of 67Ga Citrate in Noninfectious Nephritis

    International Nuclear Information System (INIS)

    Lee, Kang Wook; Jeong, Min Soo; Rhee, Sunn Kgoo; Kim, Sam Yong; Shin, Young Tai; Ro, Heung Kyu

    1992-01-01

    67 Ga citrate scan has been requested for detection or follow-up of inflammatory or neoplastic disease. Visualization of 67 Ga citrate in the kidneys at 48 and 72 hr post injection is usually interpreted as evidence of renal pathology. But precise mechanisms of abnormal 67 Ga uptake in kidneys were unknown. We undertook a study to determine the clinical value of 67 Ga citrate imaging of the kidneys in 68 patients with primary or secondary nephropathy confirmed by renal biopsy and 66 control patients without renal disease. Renal uptake in 48 to 72 hr images was graded as follows: Grade 0=background activity;1=faint uptake greater than background; 2=definite uptake, but less than lumbar vertebrae;3 same uptake as lumbar vertebrae, but less than liver; 4=same or higher uptake than liver. The results were as follows. 1) 42 of 68(62%) patients with noninfectious nephritis showed grade 2 or higher 67 Ga renal uptake but only 10 percent of control patients showed similar uptake. 2) In 14 patients with systemic lupus erythematosus, 8 of 9 (89%) patients with lupus nephritis exhibited marked renal uptake. 3) 36 of 41 patients (88%) with combined nephrotic syndrome showed Grade 2 or higher renal uptake. 4) Renal 67 Ga uptake was correlated with clinical severity of nephrotic syndrome determined by serum albumin level, 24 hr urine protein excretion and serum lipid levels. 5) After complete remission of nephrotic syndrome, renal uptake in all 8 patients who were initially Grade 3 or 4, decreased to Grade 1 or 0. In conclusion, we think that the mechanism of renal 67 Ga uptake in nephrotic syndrome might be related to the pathogenesis of nephrotic syndrome. In systemic lupus erythematosus, 67 Ga citrate scan is useful in predicting renal involvement.

  1. 67Ga-citrate scanning in gastrointestinal malignancies

    International Nuclear Information System (INIS)

    Douds, H.N.; Berens, S.V.; Long, R.F.; Caplan, G.E.

    1978-01-01

    The value of 67 Ga-citrate scanning in cases of gastrointestinal malignancies is discussed. Seven cases are presented, including lymphomas of the stomach, small bowel, and rectum, and adenocarcinomas of the stomach and colon. In a review of the literature, there is general pessimism regarding the use of 67 Ga scans in GI malignancies. Based on previous reports and our own experience, specific clinical situations are cited in which the scan is of considerable value for diagnosis and followup of GI malignancy

  2. Synthesis and characterization of poly(glycerol citrate/sebacate)

    International Nuclear Information System (INIS)

    Brioude, Michel M.; Guimaraes, Danilo H.; Fiuza, Raigenis P.; Boaventura, Jaime S.; Jose, Nadia M.

    2011-01-01

    In this work were prepared and characterized the poly(glycerol citrate/sebacate) in three different ratios between acids. The polymers were prepared by a polycondensation reaction between glycerol and citric/sebacic acids and characterized by X-ray diffraction (XRD), infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), scanning differential calorimetry (DSC), scanning electron microscopy (SEM). The results showed that the polymers are polyesters and its crystallinity, thermal and morphological properties were modified by sebacic acid adding. (author)

  3. Diagnosis of mycotic abdominal aortic aneurysm using 67-gallium citrate

    International Nuclear Information System (INIS)

    Blumoff, R.L.; McCartney, W.; Jaques, P.; Johnson, G. Jr.

    1982-01-01

    Mycotic aneurysms of the abdominal aorta are uncommon, but potentially lethal problems. Clinical subtleties may suggest their presence, but in the past, definitive diagnosis has been dependent on surgical exploration or autopsy findings. A case is presented in which 67-gallium citrate abdominal scanning localized the site of sepsis in an abdominal aortic aneurysm and allowed for prompt and successful surgical therapy. This noninvasive technique is recommended as a adjunct in the diagnosis of mycotic abdominal aortic aneurysms

  4. Targeted proteins involved in the neuroprotective effects of lithium citrate

    OpenAIRE

    I. Yu. Torshin; O. A. Gromova; L. A. Mayorova; A. Yu. Volkov

    2017-01-01

    Preparations based on organic lithium salts are promising neuroprotective agents that are effective just in the micromolar concentration range and, at the same time, have high safety (Toxicity Class V).Objective: to elucidate more detailed mechanisms responsible for the biological and pharmacological effects of lithium citrate, by analyzing the possible interactions of lithium ion with human proteome proteins that are also represented in the rat proteome.Material and methods. The targets of l...

  5. PZ, PT and PZT formation from metal citrates

    International Nuclear Information System (INIS)

    Bastos, C.M.R.; Zaghette, M.A.; Jafelicci Junior, M.; Varela, J.A.

    1990-01-01

    Lead zirconate, lead titanate and lead titanate-zirconate were obtained by mechanical mixing of lead, titanium and zirconium citrates in ether and by calcination. The process was analyzed by DTA, TGA, IR, pore size distribution and surface area measurements. The results indicate that the decomposition reaction and formation of PZ, PT occur simultaneaously without formation of intermediate compounds. PZT was formed from 500 0 C. (author) [pt

  6. Subclinical abortions in patients treated with clomiphene citrate

    International Nuclear Information System (INIS)

    Ho, P.C.; Tang, G.W.

    1982-01-01

    Using radioimmunoassay for human chorionic gonadotrophin beta-subunit, 39 treatment cycles of clomiphene citrate therapy were studied prospectively for incidence of subclinical abortions. Eight treatment cycles resulted in clinically recognizable pregnancies and three other treatment cycles ended up with subclinical abortions. The plasma progesterone levels in patients with subclinical abortions at the 13th day after ovulation were lower than those in patients with normal pregnancies. (author)

  7. Comparison of EDTA and EDDS as potential soil amendments for enhanced phytoextraction of heavy metals.

    Science.gov (United States)

    Meers, E; Ruttens, A; Hopgood, M J; Samson, D; Tack, F M G

    2005-02-01

    Phytoextraction has been proposed as an alternative remediation technology for soils polluted with heavy metals or radionuclides, but is generally conceived as too slow working. Enhancing the accumulation of trace pollutants in harvestable plant tissues is a prerequisite for the technology to be practically applicable. The chelating aminopolycarboxylic acid, ethylene diamine tetraacetate (EDTA), has been found to enhance shoot accumulation of heavy metals. However, the use of EDTA in phytoextraction may not be suitable due to its high environmental persistence, which may lead to groundwater contamination. This paper aims to assess whether ethylene diamine disuccinate (EDDS), a biodegradable chelator, can be used for enhanced phytoextraction purposes. A laboratory experiment was conducted to examine mobilisation of Cd, Cu, Cr, Ni, Pb and Zn into the soil solution upon application of EDTA or EDDS. The longevity of the induced mobilisation was monitored for a period of 40 days after application. Estimated effect half lives ranged between 3.8 and 7.5 days for EDDS, depending on the applied dose. The minimum observed effect half life of EDTA was 36 days, while for the highest applied dose no decrease was observed throughout the 40 day period of the mobilisation experiment. Performance of EDTA and EDDS for phytoextraction was evaluated by application to Helianthus annuus. Two other potential chelators, known for their biodegradability in comparison to EDTA, were tested in the plant experiment: nitrilo acetic acid (NTA) and citric acid. Uptake of heavy metals was higher in EDDS-treated pots than in EDTA-treated pots. The effects were still considered insufficiently high to consider efficient remediation. This may be partly due to the choice of timing for application of the soil amendment. Fixing the time of application at an earlier point before harvest may yield better results. NTA and citric acid induced no significant effects on heavy metal uptake.

  8. Evaluation of di-amino phenol substituted EDTA for use in radiolabelling proteins with 64Cu

    International Nuclear Information System (INIS)

    Schmidt, P.F.; Smith, S.V.; DiBartolo, N.M.

    1996-01-01

    This study involves a high yielding synthesis of a novel di-amino-phenol substituted EDTA (DAHA-EDTA) ligand and its radiolabelling chemistry with 64 Cu produced at the National Medical Cyclotron (NMC). High activity levels (up to 59.2 GBq EOB) of 64 Cu is co-produced during the production of 67 Ga from enriched 68 Zn. Waste eluent from the NMC 67 Ga production was evaporated to dryness and found to contain by products such as 57 Ni, 57 Co, 64 Cu, 67 Cu and 55 Co. A new method involving low acid concentration aqueous/organic mixtures with an anion exchange (AG 1-X8, BioRad) have been used to isolate the carrier-free 64 Cu. The specific activity of the 64 Cu (5 x 10 14 Bq/g) was found to be higher than that produce by Australian radioisotopes (ARI). The synthesis of the ligand involves the refluxing of EDTA anhydride in the presence of 4-nitro-2-amino-phenol in acetonitrile to produce the di-nitro derivative (DNHA- EDTA) in > 95% yield. The DNHA-EDTA is then reduced in the presence of activated palladium charcoal with sodium borohydride under an inert atmosphere at room temperature. The reaction mixture was acidified and the catalyst removed to obtain the final product, DAHA-EDTA. Labelling of proteins (B72.3, DD-3B6/22 and streptavidin) has been achieved with the DAHA-EDTA ligand. The reaction mixture is left to incubate for 1 h at 37 deg C and radiolabelled protein is then isolated using size exclusion chromatography

  9. Production and characterization of monoclonal antibodies to the edta extract of Leptospira interrogans, serovar icterohaemorrhagiae

    Directory of Open Access Journals (Sweden)

    Lilian Terezinha de Queiroz Leite

    1996-10-01

    Full Text Available Monoclonal antibodies (MABs ivere produced against an etbylenediaminetetraacetate (EDTA extract of Leptospira interrogans serovar icterohaemorrhagiae being characterized by gel precipitation as IgM and IgG (IgGl and IgG2b. The EDTA extract was detected as several bands by silver staining in SDS-PAGE. In the Western blot the bands around 20 KDa reacted with a monoclonal antibody, 47B4D6, and was oxidized by periodate and was not digested by pronase, suggesting that the determinant is of carbohydrate nature, lmmunocytochemistry, using colloidal gold labeling, showed that an EDTA extract determinant recognized by monoclonal antibody 47B4D6, is localized under the outer envelope of serovar icterohaemorrhagiae. Hoe AIAB raised against the EDTA extract was not able to protect hamsters from lethal challenge with virulent homologous leptospires.Anticorpos monoclonais (AcM foram produzidos contra o extrato EDTA obtido de Leptospira interrogans, sorovar icterohaemorrhagiae. Pelo teste de precipitação foram caracterizados como IgM e IgG (IgGl e IgG2. A eletroforese em gel de poliacrilamida do extrato EDTA revelou diversas bandas quando corada pela prata. No "Western blot", as bandas em torno de 20 kDa reagiram com o AcM 47B4D6, foram oxidadas pelo periodato e não digeridas pela pronase, sugerindo que o determinante é de natureza carboidrato. O determinante reconhecido pelo AcM 47B4D6 estã localizado sob o envelope externo como revelado pela imunocitoquímica usando marcação com ouro coloidal. O AcM contra extrato EDTA do sorovar icterohaemorrahagiae não protegeu hamsters quando inoculados com lepstopira homóloga virulenta.

  10. Dynamics of meso and thermo citrate synthases with implicit solvation

    Science.gov (United States)

    Cordeiro, J. M. M.

    The dynamics of hydration of meso and thermo citrate synthases has been investigated using the EEF1 methodology implemented with the CHARMM program. The native enzymes are composed of two identical subunits, each divided into a small and large domain. The dynamics behavior of both enzymes at 30°C and 60°C has been compared. The results of simulations show that during the hydration process, each subunit follows a different pathway of hydration, in spite of the identical sequence. The hydrated structures were compared with the crystalline structure, and the root mean square deviation (RMSD) of each residue along the trajectory was calculated. The regions with larger and smaller mobility were identified. In particular, helices belonging to the small domain are more mobile than those of the large domain. In contrast, the residues that constitute the active site show a much lower displacement compared with the crystalline structure. Hydration free energy calculations point out that Thermoplasma acidophilum citrate synthase (TCS) is more stable than chicken citrate synthase (CCS), at high temperatures. Such result has been ascribed to the higher number of superficial charges in the thermophilic homologue, which stabilizes the enzyme, while the mesophilic homologue denatures. These results are in accord with the experimental found that TCS keeps activity at temperatures farther apart from the catalysis regular temperature than the CCS.

  11. Melatonin: Buffering the Immune System

    Directory of Open Access Journals (Sweden)

    Juan M. Guerrero

    2013-04-01

    Full Text Available Melatonin modulates a wide range of physiological functions with pleiotropic effects on the immune system. Despite the large number of reports implicating melatonin as an immunomodulatory compound, it still remains unclear how melatonin regulates immunity. While some authors argue that melatonin is an immunostimulant, many studies have also described anti-inflammatory properties. The data reviewed in this paper support the idea of melatonin as an immune buffer, acting as a stimulant under basal or immunosuppressive conditions or as an anti-inflammatory compound in the presence of exacerbated immune responses, such as acute inflammation. The clinical relevance of the multiple functions of melatonin under different immune conditions, such as infection, autoimmunity, vaccination and immunosenescence, is also reviewed.

  12. Melatonin: Buffering the Immune System

    Science.gov (United States)

    Carrillo-Vico, Antonio; Lardone, Patricia J.; Álvarez-Sánchez, Nuria; Rodríguez-Rodríguez, Ana; Guerrero, Juan M.

    2013-01-01

    Melatonin modulates a wide range of physiological functions with pleiotropic effects on the immune system. Despite the large number of reports implicating melatonin as an immunomodulatory compound, it still remains unclear how melatonin regulates immunity. While some authors argue that melatonin is an immunostimulant, many studies have also described anti-inflammatory properties. The data reviewed in this paper support the idea of melatonin as an immune buffer, acting as a stimulant under basal or immunosuppressive conditions or as an anti-inflammatory compound in the presence of exacerbated immune responses, such as acute inflammation. The clinical relevance of the multiple functions of melatonin under different immune conditions, such as infection, autoimmunity, vaccination and immunosenescence, is also reviewed. PMID:23609496

  13. Modelling of buffer material behaviour

    International Nuclear Information System (INIS)

    Boergesson, L.

    1988-12-01

    Some material models of smectite rich buffer material suited for nuclear waste isolation are accounted for in the report. The application of these models in finite element calculations of some scenarios and performance are also shown. The rock shear scenario has been closely studied with comparisons between calculated and measured results. Sensitivity analyses of the effect of changing the density of the clay and the rate of shear have been performed as well as one calculation using a hollow steel cylinder. Material models and finite element calculations of canister settlement, thermomechanical effects and swelling are also accounted for. The report shows the present state of the work to establish material models and calculation tools which can be used at the final design of the repository. (31 illustrations)

  14. The impact of EDTA on lead distribution and speciation in the accumulator Sedum alfredii by synchrotron X-ray investigation

    International Nuclear Information System (INIS)

    Tian Shengke; Lu Lingli; Yang Xiaoe; Huang Huagang; Brown, Patrick; Labavitch, John; Liao Haibing; He Zhenli

    2011-01-01

    The in vivo localization and speciation of lead (Pb) in tissues of the accumulator Sedum alfredii grown in EDTA-Pb and Pb(NO 3 ) 2 was studied by synchrotron X-ray investigation. The presence of EDTA-Pb in solution resulted in a significant reduction of Pb accumulation in S. alfredii. Lead was preferentially localized in the vascular bundles regardless of treatments but the intensities of Pb were lower in the plants treated with EDTA. Lead was predominantly presented as a Pb-cell wall complex in the plants regardless of its supply form. However, a relatively high proportion of Pb was observed as Pb-EDTA complex when the plant was treated with EDTA-Pb, but as a mixture of Pb 3 (PO 4 ) 2 , Pb-malic, and Pb-GSH when cultured with ionic Pb. These results suggest that EDTA does not increase the internal mobility of Pb, although the soluble Pb-EDTA complex could be transported and accumulated within the plants of S. alfredii. - Research highlights: → The plants of S. alfredii are less effective in taking up Pb from the EDTA-Pb medium. → Pb is mainly localized in the vascular bundles and probably as Pb-cell wall complex. → EDTA does not increase the internal mobility of Pb within the plants of S. alfredii. → The Pb-EDTA complex could be transported and accumulated within the plants. - The plants of S. alfredii are able to transport and accumulate the Pb-EDTA complex, but are less effective in taking up Pb from the EDTA-Pb medium.

  15. The impact of EDTA on lead distribution and speciation in the accumulator Sedum alfredii by synchrotron X-ray investigation

    Energy Technology Data Exchange (ETDEWEB)

    Tian Shengke [MOE Key Laboratory of Environment Remediation and Ecological Health, College of Environmental and Resource Science, Zhejiang University, Hangzhou 310029 (China); Lu Lingli, E-mail: linglilulu@gmail.com [MOE Key Laboratory of Environment Remediation and Ecological Health, College of Environmental and Resource Science, Zhejiang University, Hangzhou 310029 (China); Yang Xiaoe, E-mail: xyang571@yahoo.com [MOE Key Laboratory of Environment Remediation and Ecological Health, College of Environmental and Resource Science, Zhejiang University, Hangzhou 310029 (China); Huang Huagang [MOE Key Laboratory of Environment Remediation and Ecological Health, College of Environmental and Resource Science, Zhejiang University, Hangzhou 310029 (China); Brown, Patrick; Labavitch, John [Department of Plant Sciences, University of California, Davis, CA 95616 (United States); Liao Haibing [MOE Key Laboratory of Environment Remediation and Ecological Health, College of Environmental and Resource Science, Zhejiang University, Hangzhou 310029 (China); He Zhenli [University of Florida, Institute of Food and Agricultural Sciences, Indian River Research and Education Center, Fort Pierce, FL 34945 (United States)

    2011-03-15

    The in vivo localization and speciation of lead (Pb) in tissues of the accumulator Sedum alfredii grown in EDTA-Pb and Pb(NO{sub 3}){sub 2} was studied by synchrotron X-ray investigation. The presence of EDTA-Pb in solution resulted in a significant reduction of Pb accumulation in S. alfredii. Lead was preferentially localized in the vascular bundles regardless of treatments but the intensities of Pb were lower in the plants treated with EDTA. Lead was predominantly presented as a Pb-cell wall complex in the plants regardless of its supply form. However, a relatively high proportion of Pb was observed as Pb-EDTA complex when the plant was treated with EDTA-Pb, but as a mixture of Pb{sub 3}(PO{sub 4}){sub 2}, Pb-malic, and Pb-GSH when cultured with ionic Pb. These results suggest that EDTA does not increase the internal mobility of Pb, although the soluble Pb-EDTA complex could be transported and accumulated within the plants of S. alfredii. - Research highlights: > The plants of S. alfredii are less effective in taking up Pb from the EDTA-Pb medium. > Pb is mainly localized in the vascular bundles and probably as Pb-cell wall complex. > EDTA does not increase the internal mobility of Pb within the plants of S. alfredii. > The Pb-EDTA complex could be transported and accumulated within the plants. - The plants of S. alfredii are able to transport and accumulate the Pb-EDTA complex, but are less effective in taking up Pb from the EDTA-Pb medium.

  16. Isolation and growth characteristics of an EDTA-degrading member of the alpha-subclass of Proteobacteria.

    Science.gov (United States)

    Weilenmann, Hans-Ueli; Engeli, Barbara; Bucheli-Witschel, Margarete; Egli, Thomas

    2004-10-01

    A Gram-negative, ethylenediaminetetraacetic acid (EDTA)-degrading bacterium (deposited at the German Culture Collection as strain DSM 9103) utilising EDTA as the only source of carbon, energy and nitrogen was isolated from a mixed EDTA-degrading population that was originally enriched in a column system from a mixture of activated sludge and soil. Chemotaxonomic analysis of quinones, polar lipids and fatty acids allowed allocation of the isolate to the alpha-subclass of Proteobacteria. 16S rDNA sequencing and phylogenetic analysis revealed highest similarity to the Mesorhizobium genus followed by the Aminobacter genus. However, the EDTA-degrading strain apparently forms a new branch within the Phyllobacteriaceae/Mesorhizobia family. Growth of the strain was rather slow not only on EDTA (micro(max) = 0.05 h(-1)) but also on other substrates. Classical substrate utilisation testing in batch culture suggested a quite restricted carbon source spectrum with only lactate, glutamate, and complexing agents chemically related to EDTA (nitrilotriacetate, iminodiacetate and ethylenediaminedisuccinate) supporting growth. However, when EDTA-limited continuous cultures of strain DSM 9103 were pulsed with fumarate, succinate, glucose or acetate, these substrates were assimilated immediately. Apparently, the strain can use a broader spectrum than indicated by traditional substrate testing techniques. The EDTA species CaEDTA and MgEDTA served as growth substrates of the strain because in the mineral medium employed EDTA was predicted to be mainly present in the form of these two complexes. The bacterium was not able to degrade Fe3+-complexed EDTA.

  17. The attachment of V79 and human periodontal ligament fibroblasts on periodontally involved root surfaces following treatment with EDTA, citric acid, or tetracycline HCL: an SEM in vitro study.

    Science.gov (United States)

    Chandra, R Viswa; Jagetia, Ganesh Chandra; Bhat, K Mahalinga

    2006-02-15

    The present in vitro study has been designed to establish and compare the effects of citric acid, EDTA, and tetracycline HCl on human periodontally diseased roots on the structure, attachment, and orientation of V79 (primary Chinese hamster lung fibroblasts) cells and human periodontal ligament fibroblasts (HPDL). Commercially available V79 cells and HPDL derived from healthy human third molars were used in this study. These fibroblasts were left in solution for seven days in order to attain confluence. Forty single-rooted teeth were obtained from patients diagnosed with periodontitis. The crown part was removed under constant irrigation and the root was split vertically into two equal halves, thus, yielding 80 specimens. Following scaling and root planing, the specimens were washed with phosphate buffered saline (PBS) and kept in 50 microg/ml gentamycin sulphate solution for 24 hours. The root pieces were then treated as follows: citric acid at pH 1, 24% EDTA, or with a 10% solution of tetracycline HCl and were then placed in V79 fibroblast cultures and HPDL cultures. The specimens were harvested after four weeks and were fixed in 2.5% glutaraldehyde in PBS before preparation for scanning electron microscopy (SEM). The behavior of V79 cells was similar to that of human periodontal ligament cells on root conditioned surfaces. V79 and HPDL showed a healthy morphology on root surfaces treated with citric acid and EDTA and a relatively unhealthy appearance on root surfaces treated with tetracycline HCl and distilled water (control group). The results suggest the use of citric acid and EDTA as root conditioning agents favorably affects the migration, attachment, and morphology of fibroblasts on human root surfaces, which may play a significant role in periodontal healing and regeneration.

  18. Signature-based store checking buffer

    Science.gov (United States)

    Sridharan, Vilas; Gurumurthi, Sudhanva

    2015-06-02

    A system and method for optimizing redundant output verification, are provided. A hardware-based store fingerprint buffer receives multiple instances of output from multiple instances of computation. The store fingerprint buffer generates a signature from the content included in the multiple instances of output. When a barrier is reached, the store fingerprint buffer uses the signature to verify the content is error-free.

  19. Efficacy of extended clomifene citrate regimen in comparison with gonadotropins in clomifene citrate-resistant women with polycystic ovary syndrome

    OpenAIRE

    Mahmoud Fathy Hassan

    2014-01-01

    Background: Gonadotropins are successful treatment for women with clomifene citrate (CC)-resistant polycystic ovary syndrome (PCOS). The aim of this study was to test the hypothesis that extended CC treatment may be an alternative to gonadotropins in the management of CC-resistant women with PCOS. Methods: A randomized controlled trial comprised 200 women with CC-resistant PCOS were allocated to two equal treatment groups. Patients in the CC group were given 100 mg of CC daily starting fr...

  20. Neptunium speciation (complexation and redox behaviour) in aqueous citrate medium

    International Nuclear Information System (INIS)

    Bonin, L.; Ansoborlo, E.; Moisy, Ph.

    2005-01-01

    Full text of publication follows: In the framework of the French Environmental Nuclear Toxicology programme, additional experiments related to the decorporation of actinides are planned. The lack of information on the neptunium behaviour within blood and the inefficiency of therapeutic treatments, led us to study the complexation of this element with basic anions. Within this purpose, the in vitro behaviour of Np IV and Np V in simple media simulating biological media was studied: blood plasma is one of the media of interest and it can be simulated, from a chemical point of view, by an aqueous solution with pH 7.4, containing ions such as citrate (1.6 10 -4 mol/L), lactate (1.5 10 -3 mol/L), CO 3 2- (2.5 10 -2 mol/L), PO 4 3- (1.1 10 -3 mol/L), SO 4 2- (3.3 10 -4 mol/L) and Cl - (9 10 -2 mol/L). This study was more specifically focused on the behaviour of neptunium with citrate ion, which is also a basic ligand to consider when one wishes to study the migration of actinides in the environment, since it exists in significant amounts in the ground due to its production by the plants. In order to determine the speciation of this system, spectrophotometry was more particularly used. Concerning the complexation phenomenon, the existence of several complexes of Np V with various acid-basic forms of the citrate anion was observed; regarding Np IV , two complexes, with 1:1 and 1:2 stoichiometry, have been respectively observed. The reactivity of Np VI is probably similar to the behaviour of U VI , which is reported in literature to form a complex with a 1:1 stoichiometry with the Cit 3- anion From the quantitative study of these equilibria, it has been possible to determine the values of various equilibrium constants. Concerning the stability of neptunium towards oxido-reduction, it was confirmed that Np VI was very quickly reduced to Np V by the citrate anions, whereas Np IV was stable. In the case of Np V , it was observed that, depending on the pH and the citrate

  1. SODR Memory Control Buffer Control ASIC

    Science.gov (United States)

    Hodson, Robert F.

    1994-01-01

    The Spacecraft Optical Disk Recorder (SODR) is a state of the art mass storage system for future NASA missions requiring high transmission rates and a large capacity storage system. This report covers the design and development of an SODR memory buffer control applications specific integrated circuit (ASIC). The memory buffer control ASIC has two primary functions: (1) buffering data to prevent loss of data during disk access times, (2) converting data formats from a high performance parallel interface format to a small computer systems interface format. Ten 144 p in, 50 MHz CMOS ASIC's were designed, fabricated and tested to implement the memory buffer control function.

  2. Chlorhexidine controlled-release profile after EDTA root surface etching: an in vivo study.

    Science.gov (United States)

    Gamal, Ahmed Y; Kumper, Radi M; Sadek, Hesham S; El Destawy, Mahmoud T

    2011-05-01

    The main objective of the present study was to quantify chlorhexidine (CHX) release after the use of CHX-EDTA root surface treatment as a local-delivery antimicrobial vehicle. Twenty non-smoking patients clinically diagnosed as having moderate-to-severe chronic periodontitis were selected to participate in this study. After cause-related therapy, one site in every patient received defect overfill with CHX gel 2% (20 sites). In addition, twenty contralateral sites received defect fill of CHX gel after 3 minutes of 24% EDTA gel root surface etching (20 sites). Gingival crevicular fluid samples were collected at 1, 3, 7, and 14 days post-therapy. The CHX-EDTA group showed statistically significantly higher levels of CHX than those of the control group at 1, 3, and 7 days. At 14 days, the CHX-EDTA group showed 0.8 mg/mL values. The use of CHX-EDTA root surface treatment as a local-delivery antimicrobial improves CHX substantivity.

  3. Intestinal permeability to [51Cr]EDTA in children with Crohn's disease and celiac disease

    International Nuclear Information System (INIS)

    Turck, D.; Ythier, H.; Maquet, E.; Deveaux, M.; Marchandise, X.; Farriaux, J.P.; Fontaine, G.

    1987-01-01

    [ 51 Cr]EDTA was used as a probe molecule to assess intestinal permeability in 7 healthy control adults, 11 control children, 17 children with Crohn's disease, and 6 children with untreated celiac disease. After subjects fasted overnight, 75 kBq/kg (= 2 microCi/kg) 51 Cr-labeled EDTA was given by mouth; 24-h urinary excretion of [ 51 Cr]EDTA was measured and expressed as a percentage of the total oral dose. Mean and SD were as follows: control adults 1.47 +/- 0.62, control children 1.59 +/- 0.55, and patients with Crohn's disease or celiac disease 5.35 +/- 1.94. The difference between control children and patients was statistically significant (p less than 0.001). These results show that intestinal permeability to [ 51 Cr]EDTA is increased among children with active or inactive Crohn's disease affecting small bowel only or small bowel and colon, and with untreated celiac disease. The [ 51 Cr]EDTA permeability test could facilitate the decision to perform more extensive investigations in children suspected of small bowel disease who have atypical or poor clinical and biological symptomatology

  4. Column leaching of chromium and nickel from a contaminated soil using EDTA and citric acid

    International Nuclear Information System (INIS)

    Jean-Soro, Liliane; Bordas, François; Bollinger, Jean-Claude

    2012-01-01

    This study investigates the column leaching of a soil contaminated mainly with Cr and Ni by using two chelants: citric acid (biodegradable) and EDTA (non-biodegradable) followed with water rinse. The chelants lead to Cr and Ni leaching, in addition to major elements (Ca, Fe, Mg, Al, Mn and Zn) showing the dissolution of soil mineral constituents. EDTA leaches more major elements and Ni than citric acid related to the respective stability of metal–chelant complexes; citric acid leaches more Cr than EDTA, certainly because of a substitution reaction with Cr(VI). In the case of alternating chelant/water applications, leaching occurs during the chelant applications, but also during water applications. In the case of chelant/water applications followed by continuous water application, both Cr and Ni leach over time. This increased mobility could be due to the residual chelant present in soil as well as to the dissolution/mobilization of mineral or organic soil fractions. - Highlights: ► Column leaching of an industrial soil contaminated with chromium and nickel. ► Citric acid or EDTA were used alternatively or followed with water rinse. ► Chelants lead to Cr and Ni leaching and the dissolution of soil mineral constituents. ► Leaching of these two metals proceeds continuously during water rinse. ► Chelants deeply impacted Cr and Ni mobility. - Citric acid or EDTA application deeply impact Cr and Ni mobility during column leaching of a contaminated soil.

  5. Efficacy of the chelating agent CaEDTA in reversing lead-induced changes in behavior.

    Science.gov (United States)

    Cory-Slechta, D A; Weiss, B

    1989-01-01

    The chelating agent CaEDTA has been reported to reverse the deficits in intellectual function and performance associated with Pb (lead) exposure in children. However, such studies have not included rigorous controls for the intervention procedures per se. The experiments reported here examined reversibility of performance changes in a rat model based on behavior sensitive to low-level Pb exposure. Rats were exposed to 50 ppm sodium or Pb acetate in drinking water from weaning. Performance maintained under a Fixed-Interval schedule of food reinforcement began at 55 days of age. Following the onset of the characteristic increase in short interresponse times (IRTs) associated with low-level Pb exposure after 35 experimental sessions, Pb treatment was terminated. Animals within both the control and Pb groups were then matched on the basis of performance indices and injected daily for 5 days with either saline, 75 mg/kg or 150 mg/kg CaEDTA. Subsequent changes in F1 performance were monitored for 35-60 sessions. No consistent effects of CaEDTA were detected in control animals. CaEDTA treatment failed to reverse the behavioral effects in Pb-exposed animals. If anything, it tended to further increase the proportion of short IRTs. These data suggest that better controlled clinical studies are warranted to evaluate the efficacy of CaEDTA in reversing Pb-induced behavioral effects before its application for these purposes becomes widespread.

  6. A scanning electron microscopy study of root surface smear layer removal after topical application of EDTA plus a detergent

    OpenAIRE

    Sampaio, José Eduardo Cezar; Campos, Flávia Pavan; Pilatti, Gibson Luiz; Theodoro, Letícia Helena; Leite, Fábio Renato Manzolli

    2005-01-01

    The aim of the present study was to compare root surface smear layer removal following topical application of EDTA and EDTA-T (Texapon). Extracted human teeth had their cementum removed and were mechanically scaled. A total of 220 root specimens were obtained and were randomly assigned to the following groups: I-saline solution(control), II-EDTA; III-EDTAT. Groups II and III specimens were assigned to different EDTA gel concentrations: 5%, 10%, 15%, 20% and 24%. Smear layer removal score was ...

  7. Effects of EDTA and low molecular weight organic acids on soil solution properties of a heavy metal polluted soil.

    Science.gov (United States)

    Wu, L H; Luo, Y M; Christie, P; Wong, M H

    2003-02-01

    A pot experiment was conducted to study the effects of EDTA and low molecular weight organic acids (LMWOA) on the pH, total organic carbon (TOC) and heavy metals in the soil solution in the rhizosphere of Brassica juncea grown in a paddy soil contaminated with Cu, Zn, Pb and Cd. The results show that EDTA and LMWOA have no effect on the soil solution pH. EDTA addition significantly increased the TOC concentrations in the soil solution. The TOC concentrations in treatments with EDTA were significantly higher than those in treatments with LMWOA. Adding 3 mmol kg(-1) EDTA to the soil markedly increased the total concentrations of Cu, Zn, Pb and Cd in the soil solution. Compared to EDTA, LMWOA had a very small effect on the metal concentrations. Total concentrations in the soil solution followed the sequence: EDTA > citric acid (CA) approximately oxalic acid (OA) approximately malic acid (MA) for Cu and Pb; EDTA > MA > CA approximately OA for Zn; and EDTA > MA > CA > OA for Cd. The labile concentrations of Cu, Zn, Pb and Cd showed similar trends to the total concentrations.

  8. Synthesis of LaNiO3 perovskite type by chelating precursor method using EDTA: optimization of chelating content

    International Nuclear Information System (INIS)

    Santos, Jose Carlos dos; Pedrosa, Anne Michelle Garrido; Mesquita, Maria Eliane; Souza, Marcelo Jose Barros de

    2011-01-01

    The perovskites are strategic materials due their catalytic, electronic and magnetic properties. These properties are influenced by the calcination and synthesis conditions. In this work was carried out the synthesis of LaNiO 3 perovskite type by chelating precursor method using EDTA and also was studied the optimization of the EDTA content in the synthesis. The synthesized materials were characterized by X-ray diffraction (XRD), thermal gravimetric analysis (TG) and Infrared Spectroscopy (FTIR). In the optimization of the EDTA content the lowest ratio of metal / EDTA used was 1.0 / 0.1, where it was possible to obtain monophasic perovskite. (author)

  9. A Role for the Krebs Cycle Intermediate Citrate in Metabolic Reprogramming in Innate Immunity and Inflammation

    Directory of Open Access Journals (Sweden)

    Niamh C. Williams

    2018-02-01

    Full Text Available Metabolism in immune cells is no longer thought of as merely a process for adenosine triphosphate (ATP production, biosynthesis, and catabolism. The reprogramming of metabolic pathways upon activation is also for the production of metabolites that can act as immune signaling molecules. Activated dendritic cells (DCs and macrophages have an altered Krebs cycle, one consequence of which is the accumulation of both citrate and succinate. Citrate is exported from the mitochondria via the mitochondrial citrate- carrier. Cytosolic metabolism of citrate to acetyl-coenzyme A (acetyl-CoA is important for both fatty-acid synthesis and protein acetylation, both of which have been linked to macrophage and DC activation. Citrate-derived itaconate has a direct antibacterial effect and also has been shown to act as an anti-inflammatory agent, inhibiting succinate dehydrogenase. These findings identify citrate as an important metabolite for macrophage and DC effector function.

  10. Temperature buffer test. Dismantling operation

    Energy Technology Data Exchange (ETDEWEB)

    Aakesson, Mattias [Clay Technology AB, Lund (Sweden)

    2010-12-15

    The Temperature Buffer Test (TBT) is a joint project between SKB/ANDRA and supported by ENRESA (modelling) and DBE (instrumentation), which aims at improving the understanding and to model the thermo-hydro-mechanical behavior of buffers made of swelling clay submitted to high temperatures (over 100 deg C) during the water saturation process. The test has been carried out in a KBS-3 deposition hole at Aespoe HRL. It was installed during the spring of 2003. Two heaters (3 m long, 0.6 m diameter) and two buffer arrangements have been investigated: the lower heater was surrounded by bentonite in the usual way, whereas the upper heater was surrounded by a ring of sand. The test was dismantled and sampled during a period from the end of October 2009 to the end of April 2010, and this report describes this operation. Different types of samples have been obtained during this operation. A large number of diameter 50 mm bentonite cores have been taken for analysis of water content and density. Large pieces, so-called big sectors, have been taken for hydro-mechanical and chemical characterizations. Finally, there has been an interest to obtain different types of interface samples in which bentonite were in contact with sand, iron or concrete. One goal has been to investigate the retrievability of the upper heater, given the possibility to remove the surrounding sand shield, and a retrieval test has therefore been performed. The sand in the shield was first removed with an industrial vacuum cleaner after loosening the material through mechanical means (with hammer drill and core machine). A front loader was subsequently used for applying a sufficient lifting force to release the heater from the bentonite underneath. The experiment has been documented in different aspects: measurements of the coordinate (height or radius) of different interfaces (between bentonite blocks and between bentonite and sand); verification of sensor positions and retrieval of sensors for subsequent

  11. Temperature buffer test. Dismantling operation

    International Nuclear Information System (INIS)

    Aakesson, Mattias

    2010-12-01

    The Temperature Buffer Test (TBT) is a joint project between SKB/ANDRA and supported by ENRESA (modelling) and DBE (instrumentation), which aims at improving the understanding and to model the thermo-hydro-mechanical behavior of buffers made of swelling clay submitted to high temperatures (over 100 deg C) during the water saturation process. The test has been carried out in a KBS-3 deposition hole at Aespoe HRL. It was installed during the spring of 2003. Two heaters (3 m long, 0.6 m diameter) and two buffer arrangements have been investigated: the lower heater was surrounded by bentonite in the usual way, whereas the upper heater was surrounded by a ring of sand. The test was dismantled and sampled during a period from the end of October 2009 to the end of April 2010, and this report describes this operation. Different types of samples have been obtained during this operation. A large number of diameter 50 mm bentonite cores have been taken for analysis of water content and density. Large pieces, so-called big sectors, have been taken for hydro-mechanical and chemical characterizations. Finally, there has been an interest to obtain different types of interface samples in which bentonite were in contact with sand, iron or concrete. One goal has been to investigate the retrievability of the upper heater, given the possibility to remove the surrounding sand shield, and a retrieval test has therefore been performed. The sand in the shield was first removed with an industrial vacuum cleaner after loosening the material through mechanical means (with hammer drill and core machine). A front loader was subsequently used for applying a sufficient lifting force to release the heater from the bentonite underneath. The experiment has been documented in different aspects: measurements of the coordinate (height or radius) of different interfaces (between bentonite blocks and between bentonite and sand); verification of sensor positions and retrieval of sensors for subsequent

  12. Comparison between total and renal plasma clearance of [51Cr]EDTA

    International Nuclear Information System (INIS)

    Broechner-Mortensen, J.; Roedbro, P.

    1976-01-01

    The total plasma (E 1 ) and renal plasma (E 2 ) clearances of [ 51 Cr]EDTA were measured simultaneously in 40 patients with a wide range of renal function. The regression equation was E 1 = 0.997E 2 + 4.1; the slope of the regression line was not significantly different from 1.00, and the intercept differed significantly from zero. The results suggest that [ 51 Cr]EDTA has a significant extrarenal clearance of approximately 4 ml/min, independent of renal function. The data are used to correct the total [ 51 Cr]EDTA plasma clearance, measured by a simplified method, to yield a rapid, accurate and precise measurement of glomerular filtration rate for routine clinical use. (Auth.)

  13. 'Scan GFR' as an alternative to 51Cr-EDTA clearance

    International Nuclear Information System (INIS)

    Osman, E.A.; Clarke, M.B.; Barrett, J.J.; Parsons, V.; Dulwich Hospital, London

    1989-01-01

    In this report 39 patients had their GFR assessed by 51 Cr-EDTA in a single shot-multiple sampling technique and also by measuring the quantitative renal uptake of 99m Tc-DTPA during a standard renal imaging test. The results showed a correlation coefficient of 0.96 between the two techniques. By using linear regression analysis the GFR was derived from the % renal uptake of DTPA in a further series of 24 patients in whom the 51 Cr-EDTA method was also employed. The two methods were compared and showed a correlation coefficient of 0.94 with a mean GFR difference of 7 ± 4.5 ml/min over a 51 Cr-EDTA range of 38-150 ml/min. (orig.) [de

  14. EDTA-assisted synthesis of rose-like ZnO architectures

    Energy Technology Data Exchange (ETDEWEB)

    Li, Zhen [Institute of Nanochemistry and Nanobiology, Shanghai University, Shanghai 201800 (China); Shanghai Applied Radiation Institute, Shanghai University, Shanghai 201800 (China); Fang, Yaoguo [Institute of Nanochemistry and Nanobiology, Shanghai University, Shanghai 201800 (China); Peng, Liwei; Wu, Minghong [Shanghai Applied Radiation Institute, Shanghai University, Shanghai 201800 (China); Pan, Dengyu

    2010-10-15

    Rose-like ZnO nanostructures were prepared by a low-temperature solution route with assistance of ethylenediaminetetraacetic acid disodium (EDTA-2Na). The morphology of ZnO nanostructures was found to change from nanowire arrays to rose- and tower-like architectures with increasing the molar ratio of EDTA-2Na/Zn{sup 2+}. Also, the shape evolution of ZnO nanostructures with time was observed from flat nanosheets to wrinkled nanosheets and to rose-like nanostructures. EDTA-2Na as a strong complexing agent was found to play a key role in the shape evolution. Photoluminescence spectra show that the rose-like ZnO architectures have more defects than the nanowire arrays. (copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  15. Interactions between 59Fe(14C)EDTA and soils containing calcium carbonate

    International Nuclear Information System (INIS)

    Hargitai-Toth, A.; Konya, J.

    1991-01-01

    Interaction between FeEDTA and calcareous soils was followed over a period of four weeks using a radiotracer technique, and a kinetic evaluation of the results was performed. 59 Fe served to determine the quantity of iron, 14 C to assay for EDTA and 45 Ca to measure calcium. During the experiment, i.e. within four weeks in case of the chernozem soil 61% and in case of the clayey meadow soil 51% of the iron chelate disappeared from the solution. The loss in soluble iron was partly due to a rapid sorption process of about an hour and partly due to the slow decomposition of FeEDTA to Fe(OH) 3 . The two processes could be separated using the Christiansen equation. (author) 9 refs.; 1 figs.; 2 tabs

  16. [51Cr]EDTA intestinal permeability in children with cow's milk intolerance

    International Nuclear Information System (INIS)

    Schrander, J.J.; Unsalan-Hooyen, R.W.; Forget, P.P.; Jansen, J.

    1990-01-01

    Making use of [ 51 Cr]EDTA as a permeability marker, we measured intestinal permeability in a group of 20 children with proven cow's milk intolerance (CMI), a group of 17 children with similar complaints where CMI was excluded (sick controls), and a group of 12 control children. [ 51 Cr]EDTA test results (mean +/- SD) were 6.85 +/- 3.64%, 3.42 +/- 0.94%, and 2.61 +/- 0.67% in the group with CMI, the sick control, and the control group, respectively. When compared to both control groups, patients with cow's milk intolerance (CMI) showed a significantly increased small bowel permeability. We conclude that the [ 51 Cr]EDTA test can be helpful for the diagnosis of cow's milk intolerance

  17. Reduction of mercury from mackerel fillet using combined solution of cysteine, EDTA, and sodium chloride.

    Science.gov (United States)

    Hajeb, P; Jinap, S

    2012-06-13

    An acidic solution containing mercury chelating agents to eliminate mercury in raw fish (mackerel) fillet was developed. The solution contained hydrochloric acid, sodium hydroxide, cysteine, EDTA, and NaCl. The optimum conditions for mercury reduction were achieved using response surface methodology (RSM) at cysteine concentration of 1.25%, EDTA of 275 mg/L, NaCl of 0.5%, pH of 3.75, and exposure time of 18 min. The optimized conditions produced a solution which can remove up to 91% mercury from raw fish fillet. Cysteine and EDTA were identified as potential chelating agents with the greatest potential for use. The solution can be employed in fish industries to reduce mercury in highly contaminated fish.

  18. (51Cr)EDTA intestinal permeability in children with cow's milk intolerance

    Energy Technology Data Exchange (ETDEWEB)

    Schrander, J.J.; Unsalan-Hooyen, R.W.; Forget, P.P.; Jansen, J. (Academic Hospital Maastricht (Netherlands))

    1990-02-01

    Making use of ({sup 51}Cr)EDTA as a permeability marker, we measured intestinal permeability in a group of 20 children with proven cow's milk intolerance (CMI), a group of 17 children with similar complaints where CMI was excluded (sick controls), and a group of 12 control children. ({sup 51}Cr)EDTA test results (mean +/- SD) were 6.85 +/- 3.64%, 3.42 +/- 0.94%, and 2.61 +/- 0.67% in the group with CMI, the sick control, and the control group, respectively. When compared to both control groups, patients with cow's milk intolerance (CMI) showed a significantly increased small bowel permeability. We conclude that the ({sup 51}Cr)EDTA test can be helpful for the diagnosis of cow's milk intolerance.

  19. Temporal Lob Epilepsi'sinde L-Arginine ve CaEDTA'nın Etkileri

    OpenAIRE

    NOYAN, Behzat

    2005-01-01

    Bu çalışmada, bir nitrik oksit (NO-) prekürsörü olan L-Arginine ve bir ekstrasellüler çinko şelatörü olan CaEDTA'nın pilokarpine HCl ile oluşturulan kısa süreli epileptik nöbet üzerine etkileri araştırıldı. Deney, nöbet kontrol (serum fizyolojik 10 µl, i.c.v., ve sonra 380 mg/kg pilokarpine HCl i.p.), L-Arginine (150 µg/10 µl, i.c.v.), CaEDTA (100 mM, 10 µl, i.c.v.), L-Arginine+CaEDTA olmak üzere 4 gruptan oluştu. Enjeksiyonlardan sonra iki saat boyunca nöbet davranışları gözlemlenen ...

  20. 21 CFR 520.1696a - Buffered penicillin powder, penicillin powder with buffered aqueous diluent.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Buffered penicillin powder, penicillin powder with... FORM NEW ANIMAL DRUGS § 520.1696a Buffered penicillin powder, penicillin powder with buffered aqueous diluent. (a) Specifications. When reconstituted, each milliliter contains penicillin G procaine equivalent...

  1. A laboratory and field evaluation of the mobility of cobalt-60/EDTA

    International Nuclear Information System (INIS)

    Jones, T.L.; Gee, G.W.; Kirkham, R.R.; Swanson, J.L.

    1983-01-01

    We have observed a time and soil type dependence in the ability of the organic complexant EDTA to keep cobalt-60 in solution. Test results indicate that short-term adsorption tests lasting 5 days or less can be misleading. In short-term tests using cobalt-60/EDTA and soil from the Hanford site, low sorption in batch tests and high mobility in column tests were observed. During long-term batch test using cobalt-60/EDTA, the percentage of cobalt remaining in solution decreased from 90% after 7 days to less than 10% after 500 days. In laboratory and field column tests where low water flow rates allowed long contact time, virtually no cobalt movement was observed even though in the field test tritium was transported over 4 meters. Long-term batch tests using cobalt-60/EDTA and soil from Savannah River burial grounds showed that cobalt remainin in solution dropped to 30% of the total cobalt added after 5 days and to less than 1% after 15 days. Batch tests using soil from Oak Ridge burial grounds were less dramatic showing cobalt in solution decreasing from 90% after 5 days to 70% after 35 days. The cobalt-60/EDTA complex appears to be dissociating and leaving uncomplexed cobalt which is readily sorbed. The dissociation seems to be rather complete in Hanford and Savannah River soil but limited in the Oak Ridge soil. The implication to waste management is that the potential for transport of cobalt by EDTA may not be as serious at all burial sites as once thought

  2. Influence of EDTA2− on the hydrothermal synthesis of CdTe nanocrystallites

    International Nuclear Information System (INIS)

    Gong Haibo; Hao Xiaopeng; Wu Yongzhong; Cao Bingqiang; Xu Hongyan; Xu Xiangang

    2011-01-01

    Transformation from Te nanorods to CdTe nanoparticles was achieved with the assistance of EDTA as a ligand under hydrothermal conditions. Experimental results showed that at the beginning of reaction Te nucleated and grew into nanorods. With the proceeding of reaction, CdTe nucleus began to emerge on the surface, especially on the tips of Te nanorods. Finally, nearly monodispersed hexagonal CdTe nanoparticles with diameters of about 200 nm were obtained. The effects of EDTA on the morphology and formation of CdTe nanoparticles were discussed in consideration of the strong ligand-effect of EDTA, which greatly decreased the concentration of Cd 2+ . Furthermore, the possible formation process of CdTe nanoparticles from Te nanorods was further proposed. The crystal structure and morphology of the products were investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM). - Graphical Abstract: Firstly, Te nucleated and grew into nanorods in the presence of EDTA 2− . Then CdTe nucleus began to emerge on Te nanorods and finally monodispersed CdTe nanoparticles were obtained. Highlights: ► EDTA serves as a strong ligand with Cd 2+ . ► The existence of EDTA constrains the nucleation of CdTe and promotes the formation of Te nanorods. ► With the proceeding of reaction, CdTe nucleus began to emerge on the surface, especially on the tips of Te nanorods. ► Nearly monodispersed hexagonal CdTe nanoparticles with diameters of about 200 nm were finally obtained.

  3. Treatment of EDTA contained reactor coolant using water dielectric barrier discharge plasma

    International Nuclear Information System (INIS)

    Song, Sang Heon; Kwon, Daniel; Kim, Gon Ho

    2005-01-01

    EDTA (Ethylene Diamine Tetraacetic Acid) is used as a main absorbent for the metal ion in the secondary loop of the nuclear reactor. Dissolving the wasted EDTA with low cost, therefore, is important issue for the maintenance of the nuclear power reactor and the protection of environment. EDTA is not easily biodegradable, furthermore these methods could make remained another pollutant as complex chemical compounds. Compared to chemical method, the physical methods, using the energetic particles and UVs, are more favorable because they dissociate the bonds of organic compounds directly without the secondary chemical reactions during the treatment. Recently, high energy electron beam, the plasma torch, and the water breakdown by high voltage pulse are applied to treatment of the waste water contained chemicals. Here consideration is narrow down to improve the interaction between the plasma and the chemical bonds of EDTA because the energetic particles; activated radicals, and UVs, are abundant in plasmas. The new method adapted of the water DBD (dielectric barrier discharge) which plasma generates directly on the top of the water contained EDTA is proposed. The application of DBD plasmas has been extended for cleaning the organic compounds from the contaminated surface and also for removing volatile organic chemicals (VOC) such as NO x and SO x from the exhausted gases. Here, the water DBD reactor (SEMTECH, SD-DWG-04-1) is consisted that the one electrode is a ceramic insulator and another one is the water itself. Interestingly, the one electrode, the water, is not the solid dielectric electrode. In this study, therefore, the characteristics with driving frequency are considered and the feasibility of this new method for the DBD treatment of EDTA contained water is demonstrated

  4. Clinical efficacy of toothpaste containing potassium citrate in treating dentin hypersensitivity

    Directory of Open Access Journals (Sweden)

    Shih-Ya Shen

    2009-12-01

    Conclusion: The prevalence of dentin hypersensitivity in this study was 38%. The use of desensitizing toothpaste containing potassium citrate with oral hygiene instruction can effectively reduce dentin hypersensitivity.

  5. Risks and benefits of citrate anticoagulation for continuous renal replacement therapy.

    Science.gov (United States)

    Shum, H P; Yan, W W; Chan, T M

    2015-04-01

    Heparin, despite its significant side-effects, is the most commonly used anticoagulant for continuous renal replacement therapy in critical care setting. In recent years, citrate has gained much popularity by improving continuous renal replacement therapy circuit survival and decreasing blood transfusion requirements. However, its complex metabolic consequences warrant modification in the design of the citrate-based continuous renal replacement therapy protocol. With thorough understanding of the therapeutic mechanism of citrate, a simple and practicable protocol can be devised. Citrate-based continuous renal replacement therapy can be safely and widely used in the clinical setting with appropriate clinical staff training.

  6. THE BUFFER CAPACITY OF AIRWAY EPITHELIAL SECRETIONS

    Directory of Open Access Journals (Sweden)

    Dusik eKim

    2014-06-01

    Full Text Available The pH of airway epithelial secretions influences bacterial killing and mucus properties and is reduced by acidic pollutants, gastric reflux, and respiratory diseases such as cystic fibrosis (CF. The effect of acute acid loads depends on buffer capacity, however the buffering of airway secretions has not been well characterized. In this work we develop a method for titrating micro-scale (30 µl volumes and use it to study fluid secreted by the human airway epithelial cell line Calu-3, a widely used model for submucosal gland serous cells. Microtitration curves revealed that HCO3- is the major buffer. Peak buffer capacity (β increased from 17 to 28 mM/pH during forskolin stimulation, and was reduced by >50% in fluid secreted by cystic fibrosis transmembrane conductance regulator (CFTR-deficient Calu-3 monolayers, confirming an important role of CFTR in HCO3- secretion. Back-titration with NaOH revealed non-volatile buffer capacity due to proteins synthesized and released by the epithelial cells. Lysozyme and mucin concentrations were too low to buffer Calu-3 fluid significantly, however model titrations of porcine gastric mucins at concentrations near the sol-gel transition suggest that mucins may contribute to the buffer capacity of ASL in vivo. We conclude that CFTR-dependent HCO3- secretion and epithelially-derived proteins are the predominant buffers in Calu-3 secretions.

  7. Shock buffer for nuclear control assembly

    International Nuclear Information System (INIS)

    Bevilacqua, F.

    1977-01-01

    A shock buffer is provided for the gradual deceleration of a rapidly descending control element assembly in a nuclear reactor. The interactive buffer components are associated respectively with the movable control element assembly and part of the upper guide structure independent of and spaced from the fuel assemblies of the reactor

  8. Bicarbonate catalysis of exchange synthesis of [51Cr]Cr(III)-EDTA and other chromium complexes

    International Nuclear Information System (INIS)

    Aronson, F.L.; Strashun, A.M.; Lopez, C.; Steigman, J.

    1993-01-01

    Exchange syntheses of trivalent chromium complexes often require heating, thus limiting tagging of heat-sensitive biological compounds with 51 Cr. Bicarbonate at pH 6, accelerates the formation of mM Cr-EDTA. Accordingly, room temperature catalysis with [ 51 Cr]Cr(III) at 10 -7 -10 -8 M was investigated. Complexes were successfully formed with EDTA and iminodiacetic acid (electrophoretic analysis) and acetylacetone and tropolone (analyzed by chloroform extraction). The formation of these complexes normally requires extensive heating. (author)

  9. The use of EDTA and DTPA for accelerating the removal of deposited transuranic elements from humans

    CERN Document Server

    Spoor, N L

    1977-01-01

    EDTA and DTPA have been prominent among the chelating agents used to increase the rate of excretion of certain deposited heavy metals from the human body. Since 1959, DTPA, administered either by intravenous injection or by aerosol inhalation, has been widely used to treat workers contaminated by plutonium or a higher actinide. In this report, an attempt is made to assess the toxicities of EDTA and DTPA and to evaluate the effectiveness and safety of DTPA as a drug for removing deposited transuranic elements.

  10. EVALUATION OF A BUFFERED SOLID PHASE DISPERSION PROCEDURE ADAPTED FOR PESTICIDE ANALYSES IN THE SOIL MATRIX

    Directory of Open Access Journals (Sweden)

    Ana María Domínguez

    2015-08-01

    Full Text Available An evaluation of the pesticides extracted from the soil matrix was conducted using a citrate-buffered solid phase dispersion sample preparation method (QuEChERS. The identification and quantitation of pesticide compounds was performed using gas chromatography-mass spectrometry. Because of the occurrence of the matrix effect in 87% of the analyzed pesticides, the quantification was performed using matrix-matched calibration. The method's quantification limits were between 0.01 and 0.5 mg kg-1. Repeatability and intermediate precision, expressed as a relative standard deviation percentage, were less than 20%. The recoveries in general ranged between 62% and 99%, with a relative standard deviation < 20%. All the responses were linear, with a correlation coefficient (r ≥0.99.

  11. Buffer sizing for multi-hop networks

    KAUST Repository

    Shihada, Basem

    2014-01-28

    A cumulative buffer may be defined for an interference domain in a wireless mesh network and distributed among nodes in the network to maintain or improve capacity utilization of network resources in the interference domain without increasing packet queuing delay times. When an interference domain having communications links sharing resources in a network is identified, a cumulative buffer size is calculated. The cumulative buffer may be distributed among buffers in each node of the interference domain according to a simple division or according to a cost function taking into account a distance of the communications link from the source and destination. The network may be monitored and the cumulative buffer size recalculated and redistributed when the network conditions change.

  12. Optimization of protein buffer cocktails using Thermofluor.

    Science.gov (United States)

    Reinhard, Linda; Mayerhofer, Hubert; Geerlof, Arie; Mueller-Dieckmann, Jochen; Weiss, Manfred S

    2013-02-01

    The stability and homogeneity of a protein sample is strongly influenced by the composition of the buffer that the protein is in. A quick and easy approach to identify a buffer composition which increases the stability and possibly the conformational homogeneity of a protein sample is the fluorescence-based thermal-shift assay (Thermofluor). Here, a novel 96-condition screen for Thermofluor experiments is presented which consists of buffer and additive parts. The buffer screen comprises 23 different buffers and the additive screen includes small-molecule additives such as salts and nucleotide analogues. The utilization of small-molecule components which increase the thermal stability of a protein sample frequently results in a protein preparation of higher quality and quantity and ultimately also increases the chances of the protein crystallizing.

  13. Antitumor effect and toxicity of free rhodium (II) citrate and rhodium (II) citrate-loaded maghemite nanoparticles in mice bearing breast cancer.

    Science.gov (United States)

    Carneiro, Marcella Lemos Brettas; Peixoto, Raphael C A; Joanitti, Graziela A; Oliveira, Ricardo G S; Telles, Luis A M; Miranda-Vilela, Ana L; Bocca, Anamélia L; Vianna, Leonora M S; da Silva, Izabel C R; de Souza, Aparecido R; Lacava, Zulmira G M; Báo, Sônia N

    2013-02-16

    Magnetic fluids containing superparamagnetic iron oxide nanoparticles represent an attractive platform as nanocarriers in chemotherapy. Recently, we developed a formulation of maghemite nanoparticles coated with rhodium (II) citrate, which resulted in in vitro cytotoxicity enhanced up to 4.6 times when compared to free rhodium (II) citrate formulation on breast carcinoma cells. In this work, we evaluate the antitumor activity and toxicity induced by these formulations in Balb/c mice bearing orthotopic 4T1 breast carcinoma. Mice were evaluated with regard to the treatments' toxicity through analyses of hemogram, serum levels of alanine aminotransferase, iron, and creatinine; DNA fragmentation and cell cycle of bone marrow cells; and liver, kidney and lung histology. In addition, the antitumor activity of rhodium (II) citrate and maghemite nanoparticles coated with rhodium (II) citrate was verified by tumor volume reduction, histology and immunohistochemistry. Regarding the treatments' toxicity, no experimental groups had alterations in levels of serum ALT or creatinine, and this suggestion was corroborated by the histopathologic examination of liver and kidney of mice. Moreover, DNA fragmentation frequency of bone marrow cells was lower than 15% in all experimental groups. On the other hand, the complexes rhodium (II) citrate-functionalized maghemite and free rhodium (II) citrate led to a marked growth inhibition of tumor and decrease in CD31 and Ki-67 staining. In summary, we demonstrated that both rhodium (II) citrate and maghemite nanoparticles coated with rhodium (II) citrate formulations exhibited antitumor effects against 4T1 metastatic breast cancer cell line following intratumoral administration. This antitumor effect was followed by inhibition of both cell proliferation and microvascularization and by tumor tissue injury characterized as necrosis and fibrosis. Remarkably, this is the first published report demonstrating the therapeutic efficacy of maghemite

  14. Comparison of the efficiency of clomiphene citrate and letrozole in combination with metformin in moderately obese clomiphene citrate-resistant polycystic ovarian syndrome patients.

    Science.gov (United States)

    Bjelica, Artur; Trninić-Pjević, Aleksandra; Mladenović-Segedi, Ljiljana; Cetković, Nenad; Petrović, Djordje

    2016-01-01

    Polycystic ovary syndrome is the most common endocrinopathy in women of reproductive-age. Therapy for those who want to get pregnant involves ovulation induction using clomiphene citrate, metformin, letrozole and gonadotropins. The aim of the study was to compare the efficacy of combinations of clomiphene citrate-metformin and letrozole-metformin in obese patients who are resistant to clomiphene citrate alone. The investigation was conducted as a retrospective study involving 60 moderately obese patients with polycystic ovary syndrome. Thirty-one of them received the clomiphene citrate-metformin, and 29 letrozole-metformin therapy. Stimulation was carried out for the procedures of intrauterine insemination (IUI). The age of patients, duration of infertility, and body mass index in both groups were similar. There was statistically significant difference in the thickness of the endometrium in favor of the group having the letrozole-metformin therapy (8.9 ± 1.7 mm) compared with the group receiving the clomiphene citrate-metformin treatment (6.3 ± 1.3 mm). The number of follicles was not statistically significantly different. Pregnancy rate in the first cycle of IUI in the clomiphene citrate group was 6.4%, and 17.2% in the letrozole group, which also was not statistically different. After the third IUI cycle, the pregnancy rate was significantly higher in the letrozole group (20.6%), while in the clomiphene citrate group it was (9.6%). This retrospective study demonstrated the advantages of the use of letrozole over clomiphene citrate in combination with metformin in moderately obese patients with polycystic ovary syndrome who are resistant to stimulation with clomiphene citrate alone.

  15. Comparison of the efficiency of clomiphene citrate and letrozole in combination with metformin in moderately obese clomiphene citrate - resistant polycystic ovarian syndrome patients

    Directory of Open Access Journals (Sweden)

    Bjelica Artur

    2016-01-01

    Full Text Available Introduction. Polycystic ovary syndrome is the most common endocrinopathy in women of reproductiveage. Therapy for those who want to get pregnant involves ovulation induction using clomiphene citrate, metformin, letrozole and gonadotropins. Objective. The aim of the study was to compare the efficacy of combinations of clomiphene citrate-metformin and letrozole-metformin in obese patients who are resistant to clomiphene citrate alone. Methods. The investigation was conducted as a retrospective study involving 60 moderately obese patients with polycystic ovary syndrome. Thirty-one of them received the clomiphene citrate-metformin, and 29 letrozole-metformin therapy. Stimulation was carried out for the procedures of intrauterine insemination (IUI. Results. The age of patients, duration of infertility, and body mass index in both groups were similar. There was statistically significant difference in the thickness of the endometrium in favor of the group having the letrozole-metformin therapy (8.9 ± 1.7 mm compared with the group receiving the clomiphene citrate-metformin treatment (6.3 ± 1.3 mm. The number of follicles was not statistically significantly different. Pregnancy rate in the first cycle of IUI in the clomiphene citrate group was 6.4%, and 17.2% in the letrozole group, which also was not statistically different. After the third IUI cycle, the pregnancy rate was significantly higher in the letrozole group (20.6%, while in the clomiphene citrate group it was (9.6%. Conclusion. This retrospective study demonstrated the advantages of the use of letrozole over clomiphene citrate in combination with metformin in moderately obese patients with polycystic ovary syndrome who are resistant to stimulation with clomiphene citrate alone.

  16. Inhibition of citric acid accumulation by manganese ions in Aspergillus niger mutants with reduced citrate control of phosphofructokinase

    Energy Technology Data Exchange (ETDEWEB)

    Schreferl, G.; Kubicek, C.P.; Roehr, M.

    1986-03-01

    Mutant strains of Aspergillus niger with reduced citrate control of carbohydrate catabolism (cic mutants) grow faster than the parent strain on media containing 5% (wt/vol) citrate. The mutants tolerated a higher intracellular citrate concentration than the parent strain. One mutant (cic-7/3) contained phosphofructokinase activity significantly less sensitive towards citrate than the enzyme from the parent strain. When this mutant was grown under citrate accumulating conditions, acidogenesis was far less sensitive to inhibition by Mn/sup 2 +/ than in the parent strain. Some of the cic mutants also showed altered citrate inhibition of NADP-specific isocitrate dehydrogenase.

  17. Transport of citrate-coated silver nanoparticles in unsaturated sand

    Science.gov (United States)

    Kumahor, Samuel; Hron, Pavel; Metreveli, George; Schaumann, Gabriele; Vogel, Hans-Jörg

    2015-04-01

    Chemical factors and physical constraints lead to coupled effects during particle transport in unsaturated porous media. Unlike for saturated transport, studies on unsaturated transport as typical for soil are currently scarce. We investigated the mobility of citrate-coated Ag NPs in unsaturated sand (grain diameter: 0.1-0.3 mm). For three flux rates and a given pore-water ionic strength (1 mM KNO3), the citrate-coated Ag NPs were less mobile at pH = 5 compared to pH = 9. The classic Derjaguin-Landau-Verwey-Overbeek (DLVO) theory suggests unfavorable deposition conditions at both, the air-water interface and solid-water interface. Breakthrough curves measured under quasi-steady state unsaturated flow showed retardation of the citrate-coated Ag NPs compared to inert solute (KBr). After flushing with nanoparticle-free 1 mM KNO3 solution (pH-adjusted), retention was much lower in deeper depths compared to the surface where the particles entered the flow field. The results show a non-linear dependence of nanoparticle (NP) mobility on flux rate and water content. Especially the observed retardation similar to equilibrium sorption is in contrast to observations under saturated flow conditions. A convection-dispersion and reaction model that combines a reversible equilibrium process and a non-equilibrium interaction process reproduced the measured breakthrough curves reasonably well. From comparison between saturated and unsaturated experiments we conclude that the air-water interface is responsible for the reversible equilibrium process while the water-solid interface accounts for irreversible soption.

  18. Glomerular filtration rate by {sup 51}chomium and {sup 113m}indium labeled EDTA in horses; Taxa de filtracao glomerular pelo EDTA marcado com {sup 51}cromo e com {sup 113m}indio em equinos

    Energy Technology Data Exchange (ETDEWEB)

    Maliska, C.; D' Almeida, J.; Pellegrini, P.M.; Schimit, T.S. [Hospital Central do Exercito (HCE), Rio de Janeiro, RJ (Brazil). Servico de Medicina Nuclear; Pinho, W.R. [Centro de Ensino Superior, Valenca, RJ (Brazil). Fac. de Medicina Veterinaria; Lima, J.E.T. [Instituto Nacional do Cancer (INCa), Rio de Janeiro, RJ (Brazil). Servico de Medicina Nuclear

    2009-07-01

    The glomerular filtration rate was determined in nine healthy horses, six male and three female, aged two to 12-year-old, by means of {sup 51}Cr and {sup 113m}In labeled EDTA single injection technique. The glomerular filtration rate was calculated from the plasma disappearance curve and the volume of distribution of the radiotracer, {sup 51}Cr-EDTA or {sup 113m}In-EDTA. The result (mean +- standard deviation) was 148.80 +- 26.42 m L.min{sup -1}.100 kg. It is concluded that the measurement of glomerular filtration rate by {sup 51}Cr-EDTA or {sup 113m}In-EDTA by single injection technique eliminates the bladder catheterization, and for its simplicity, convenience, accuracy, and low dose of radiation, can be used in horses as a method of choice in clinical routine. (author)

  19. Bilateral cerebral hemispheric infarction associated with sildenafil citrate (Viagra) use.

    Science.gov (United States)

    Kim, K-K; Kim, D G; Ku, Y H; Lee, Y J; Kim, W-C; Kim, O J; Kim, H S

    2008-03-01

    Sildenafil citrate (Viagra) is one of the frequently prescribed drugs for men with erectile dysfunction. We describe a 52-year-old man with bilateral middle cerebral artery (MCA) territory infarction after sildenafil use. He ingested 100 mg of sildenafil and about 1 h later, he complained of chest discomfort, palpitation and dizziness followed by mental obtundation, global aphasia and left hemiparesis. Brain magnetic resonance imaging documented acute bilateral hemispheric infarction, and cerebral angiography showed occluded bilateral MCA. Despite significant bilateral MCA stenosis and cerebral infarction, systemic hypotension persisted for a day. We presume that cerebral infarction was caused by cardioembolism with sildenafil use.

  20. Caffeine citrate - Is it a silver bullet in neonatology?

    Science.gov (United States)

    Shrestha, Bikash; Jawa, Gaurav

    2017-10-01

    Caffeine citrate is one of the most prescribed drug in the present day NICU for apnea. Its efficacy, tolerability, wide therapeutic index and safety margin has made it the drug of choice among the methylxanthines. Its therapeutic uses in apnea of prematurity, mechanical ventilation, bronchopulmonary dysplasia has made it a "silver bullet" in neonatology. However, there are still controversies surrounding this drug. This review is aimed to update the reader about the basic pharmacology, current therapeutic uses, adverse effects, controversies as well as present and future research of caffeine. Copyright © 2017. Published by Elsevier B.V.

  1. Caffeine citrate – Is it a silver bullet in neonatology?

    Directory of Open Access Journals (Sweden)

    Bikash Shrestha

    2017-10-01

    Full Text Available Caffeine citrate is one of the most prescribed drug in the present day NICU for apnea. Its efficacy, tolerability, wide therapeutic index and safety margin has made it the drug of choice among the methylxanthines. Its therapeutic uses in apnea of prematurity, mechanical ventilation, bronchopulmonary dysplasia has made it a “silver bullet” in neonatology. However, there are still controversies surrounding this drug. This review is aimed to update the reader about the basic pharmacology, current therapeutic uses, adverse effects, controversies as well as present and future research of caffeine.

  2. COMBINATIONS OF BUFFER-STOCKS AND BUFFER-FUNDS FOR WOOL PRICE STABILISATION IN AUSTRALIA

    OpenAIRE

    Moir, Brian; Piggott, Roley R.

    1991-01-01

    In this paper a preliminary analysis is presented of a combined buffer-fund and buffer-stock as an alternative to a pure buffer-fund or a pure buffer stock for stabilising wool prices. The alternatives analysed are designed so that each provides the same prices to producers as did the Reserve Price Scheme over the period of analysis. Least-cost combinations of policy instruments are derived. The results show that there is considerable potential for cost savings to be made by combining buffer-...

  3. Lithium increases ammonium excretion leading to altered urinary acid-base buffer composition.

    Science.gov (United States)

    Trepiccione, Francesco; Altobelli, Claudia; Capasso, Giovambattista; Christensen, Birgitte Mønster; Frische, Sebastian

    2017-11-24

    Previous reports identify a voltage dependent distal renal tubular acidosis (dRTA) secondary to lithium (Li + ) salt administration. This was based on the inability of Li + -treated patients to increase the urine-blood (U-B) pCO 2 when challenged with NaHCO 3 and, the ability of sodium neutral phosphate or Na 2 SO 4 administration to restore U-B pCO 2 in experimental animal models. The underlying mechanisms for the Li + -induced dRTA are still unknown. To address this point, a 7 days time course of the urinary acid-base parameters was investigated in rats challenged with LiCl, LiCitrate, NaCl, or NaCitrate. LiCl induced the largest polyuria and a mild metabolic acidosis. Li + -treatment induced a biphasic response. In the first 2 days, proper urine volume and acidification occurred, while from the 3rd day of treatment, polyuria developed progressively. In this latter phase, the LiCl-treated group progressively excreted more NH 4 + and less pCO 2 , suggesting that NH 3 /NH 4 + became the main urinary buffer. This physiological parameter was corroborated by the upregulation of NBCn1 (a marker of increased ammonium recycling) in the inner stripe of outer medulla of LiCl treated rats. Finally, by investigating NH 4 + excretion in ENaC-cKO mice, a model resistant to Li + -induced polyuria, a primary role of the CD was confirmed. By definition, dRTA is characterized by deficient urinary ammonium excretion. Our data question the presence of a voltage-dependent Li + -induced dRTA in rats treated with LiCl for 7 days and the data suggest that the alkaline urine pH induced by NH 3 /NH 4 + as the main buffer has lead to the interpretation dRTA in previous studies.

  4. Microbial reduction of [Co(III)-EDTA]⁻ by Bacillus licheniformis SPB-2 strain isolated from a solar salt pan.

    Science.gov (United States)

    Paraneeiswaran, Arunachalam; Shukla, Sudhir K; Prashanth, K; Rao, T Subba

    2015-01-01

    Naturally stressed habitats are known to be repositories for novel microorganisms with potential bioremediation applications. In this study, we isolated a [Co(III)-EDTA](-) reducing bacterium Bacillus licheniformis SPB-2 from a solar salt pan that is exposed to constant cycles of hydration and desiccation in nature. [Co(III)-EDTA](-) generated during nuclear waste management process is difficult to remove from the waste due to its high stability and solubility. It is reduced form i.e. [Co(II)-EDTA](2-) is less stable though it is toxic. This study showed that B. licheniformis SPB-2 reduced 1mM [Co(III)-EDTA](-) in 14 days when grown in a batch mode. However, subsequent cycles showed an increase in the reduction activity, which was observed up to four cycles. Interestingly, the present study also showed that [Co(III)-EDTA](-) acted as an inducer for B. licheniformis SPB-2 spore germination. Vegetative cells germinated from the spores were found to be involved in [Co(III)-EDTA](-) reduction. More detailed investigations showed that after [Co(III)-EDTA](-) reduction, i.e. [Co(II)-EDTA](2-) complex was removed by B. licheniformis SPB-2 from the bulk liquid by adsorption phenomenon. The bacterium showed a D10 value (radiation dose required to kill 90% cells) of ∼250 Gray (Gy), which signifies the potential use of B. licheniformis SPB-2 for bioremediation of moderately active nuclear waste. Copyright © 2014 Elsevier B.V. All rights reserved.

  5. Buffer mass test - Site documentation

    International Nuclear Information System (INIS)

    Pusch, R.

    1983-10-01

    The purpose of this report is to compile test site data that are assumed to be of importance for the interpretation of the Buffer Mass Test. Since this test mainly concerns water uptake and migration processes in the integrated rock/backfill system and the development of temperature fields in this system, the work has been focused on the constitution and hydrology of the rock. The major constitutional rock feature of interest for the BMT is the frequency and distribution of joints and fractures. The development of models for water uptake into the highly compacted bentonite in the heater holes requires a very detailed fracture survey. The present investigation shows that two of the holes (no. 1 and 2) are located in richly fractured rock, while the others are located in fracture-poor to moderately fractured rock. The hydrological conditions of the rock in the BMT area are characterized by water pressures of as much as 100 m water head at a few meters distance from the test site. The average hydraulic conductivity of the rock that confines the BMT tunnel has been estimated at about 10 -10 m/s by Lawrence Laboratory. The actual distribution of the water that enters the tunnel has been estimated by observing the successive moistening after having switched off the ventilation, and this has offered basis of predicting the rate and uniformity of the water uptake in the tunnel backfill. As to the heater holes the detailed fracture patterns and various inflow measurements have yielded a similar basis. The report also gives major data on the rock temperature, gas conditions, mineralogy, rock mechanics, and groundwater chemistry for BMT purposes. (author)

  6. Temperature buffer test. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Aakesson, Mattias [Clay Technology AB, Lund (Sweden)

    2012-04-15

    The Temperature Buffer Test (TBT) is a joint project between SKB/ANDRA and supported by ENRESA (modelling) and DBE (instrumentation), which aims at improving the understanding and to model the thermo-hydro-mechanical behavior of buffers made of swelling clay submitted to high temperatures (over 100 deg C) during the water saturation process. The test has been carried out in a KBS-3 deposition hole at Aspo HRL. It was installed during the spring of 2003. Two steel heaters (3 m long, 0.6 m diameter) and two buffer arrangements have been investigated: the lower heater was surrounded by rings of compacted Wyoming bentonite only, whereas the upper heater was surrounded by a composite barrier, with a sand shield between the heater and the bentonite. The test was dismantled and sampled during the winter of 2009/2010. This report is the final report and a summary of all work performed within the TBT project. The design and the installation of the different components are summarized: the depositions hole, the heating system, the bentonite blocks with emphasis on the initial density and water content in these, the filling of slots with sand or pellets, the retaining construction with the plug, lid and nine anchor cables, the artificial saturation system, and finally the instrumentation. An overview of the operational conditions is presented: the power output from heaters, which was 1,500 W (and also 1,600 W) from each heater during the first {approx}1,700 days, and then changed to 1,000 and 2,000 W, for the upper and lower heater respectively, during the last {approx}600 days. From the start, the bentonite was hydrated with a groundwater from a nearby bore-hole, but this groundwater was replaced with de-ionized water from day {approx}1,500, due to the high flow resistance of the injections points in the filter, which implied that a high filter pressure couldn't be sustained. The sand shield around the upper heater was hydrated from day {approx}1,500 to day {approx}1

  7. Temperature buffer test. Final report

    International Nuclear Information System (INIS)

    Aakesson, Mattias

    2012-04-01

    The Temperature Buffer Test (TBT) is a joint project between SKB/ANDRA and supported by ENRESA (modelling) and DBE (instrumentation), which aims at improving the understanding and to model the thermo-hydro-mechanical behavior of buffers made of swelling clay submitted to high temperatures (over 100 deg C) during the water saturation process. The test has been carried out in a KBS-3 deposition hole at Aspo HRL. It was installed during the spring of 2003. Two steel heaters (3 m long, 0.6 m diameter) and two buffer arrangements have been investigated: the lower heater was surrounded by rings of compacted Wyoming bentonite only, whereas the upper heater was surrounded by a composite barrier, with a sand shield between the heater and the bentonite. The test was dismantled and sampled during the winter of 2009/2010. This report is the final report and a summary of all work performed within the TBT project. The design and the installation of the different components are summarized: the depositions hole, the heating system, the bentonite blocks with emphasis on the initial density and water content in these, the filling of slots with sand or pellets, the retaining construction with the plug, lid and nine anchor cables, the artificial saturation system, and finally the instrumentation. An overview of the operational conditions is presented: the power output from heaters, which was 1,500 W (and also 1,600 W) from each heater during the first ∼1,700 days, and then changed to 1,000 and 2,000 W, for the upper and lower heater respectively, during the last ∼600 days. From the start, the bentonite was hydrated with a groundwater from a nearby bore-hole, but this groundwater was replaced with de-ionized water from day ∼1,500, due to the high flow resistance of the injections points in the filter, which implied that a high filter pressure couldn't be sustained. The sand shield around the upper heater was hydrated from day ∼1,500 to day ∼1,800. The sensors data concerning

  8. Calcium EDTA toxicity: renal excretion of endogenous trace metals and the effect of repletion on collagen degradation in the rat.

    Science.gov (United States)

    Braide, V B

    1984-01-01

    Studies on total hydroxyproline concentrations in urine of rats infused with toxic doses of CaEDTA at 6 mmol/kg per 24 hr for 48 hr or injected i.p. with the chelate at 4.8 mmol/kg/day for 10 days, indicate a two- to six-fold increase in urine excretion of the imino acid. This is due to increased degradation of collagen induced by CaEDTA. CaEDTA infusion was also shown to enhance urine excretion of some trace metals (Zn, Mn, Cu and Fe). Rats infused with CaEDTA for 36 hr showed a gradual fall in concentration of hydroxyproline in the urine, following cessation of chelate infusion. The decline in hydroxyproline concentrations was faster in rats receiving trace metal (Zn, Co, Mn or Ni) treatment during the post-CaEDTA infusion period; suggesting that the metals may affect collage, making the protein less susceptible to degradation in the body.

  9. Dynamic mechanical properties of buffer material

    International Nuclear Information System (INIS)

    Takaji, Kazuhiko; Taniguchi, Wataru

    1999-11-01

    The buffer material is expected to maintain its low water permeability, self-sealing properties, radionuclides adsorption and retardation properties, thermal conductivity, chemical buffering properties, overpack supporting properties, stress buffering properties, etc. over a long period of time. Natural clay is mentioned as a material that can relatively satisfy above. Among the kinds of natural clay, bentonite when compacted is superior because (i) it has exceptionally low water permeability and properties to control the movement of water in buffer, (ii) it fills void spaces in the buffer and fractures in the host rock as it swells upon water uptake, (iii) it has the ability to exchange cations and to adsorb cationic radioelements. In order to confirm these functions for the purpose of safety assessment, it is necessary to evaluate buffer properties through laboratory tests and engineering-scale tests, and to make assessments based on the ranges in the data obtained. This report describes the procedures, test conditions, results and examinations on the buffer material of dynamic triaxial tests, measurement of elastic wave velocity and liquefaction tests that aim at getting hold of dynamic mechanical properties. We can get hold of dependency on the shearing strain of the shearing modulus and hysteresis damping constant, the application for the mechanical model etc. by dynamic triaxial tests, the acceptability of maximum shearing modulus obtained from dynamic triaxial tests etc. by measurement of elastic wave velocity and dynamic strength caused by cyclic stress etc. by liquefaction tests. (author)

  10. Buffer-regulated biocorrosion of pure magnesium.

    Science.gov (United States)

    Kirkland, Nicholas T; Waterman, Jay; Birbilis, Nick; Dias, George; Woodfield, Tim B F; Hartshorn, Richard M; Staiger, Mark P

    2012-02-01

    Magnesium (Mg) alloys are being actively investigated as potential load-bearing orthopaedic implant materials due to their biodegradability in vivo. With Mg biomaterials at an early stage in their development, the screening of alloy compositions for their biodegradation rate, and hence biocompatibility, is reliant on cost-effective in vitro methods. The use of a buffer to control pH during in vitro biodegradation is recognised as critically important as this seeks to mimic pH control as it occurs naturally in vivo. The two different types of in vitro buffer system available are based on either (i) zwitterionic organic compounds or (ii) carbonate buffers within a partial-CO(2) atmosphere. This study investigated the influence of the buffering system itself on the in vitro corrosion of Mg. It was found that the less realistic zwitterion-based buffer did not form the same corrosion layers as the carbonate buffer, and was potentially affecting the behaviour of the hydrated oxide layer that forms on Mg in all aqueous environments. Consequently it was recommended that Mg in vitro experiments use the more biorealistic carbonate buffering system when possible.

  11. Citrate-based open-quotes Talspeakclose quotes actinide-lanthanide separation process

    International Nuclear Information System (INIS)

    Del Cul, G.D.; Toth, L.M.; Bond, W.D.

    1997-01-01

    Lanthanide elements are produced in relatively high yield by fission of 235 U. Almost all the lanthanide isotopes decay to stable nonradioactive lanthanide isotopes in a relatively short time. Consequently, it is highly advantageous to separate the relatively small actinide fraction from the relatively large quantities of lanthanide isotopes. The TALSPEAK process (Trivalent Actinide Lanthanide Separations by Phosphorus-reagent Extraction from Aqueous Complexes) is one of the few means available to separate the trivalent actinides from the lanthanides. Previous work based on the use of lactic or glycolic acid has shown deleterious effects of some impurity ions such as zirconium(IV), even at concentrations on the order of 10 -4 M. Other perceived problems were the need to maintain the pH and reagent concentrations within a narrow range and a significant solubility of the organic phase at high carboxylic acid concentrations. The authors' cold experiments showed that replacing the traditional extractants glycolic or lactic acid with citric acid eliminates or greatly reduces the deleterious effects produced by impurities such as zirconium. An extensive series of batch tests was done using a wide range of reagent concentrations at different pH values, temperatures, and contact times. The results demonstrated that the citrate-based TALSPEAK can tolerate appreciable changes in pH and reagent concentrations while maintaining an adequate lanthanide extraction. Experiments using a three-stage glass mixer-settler showed a good lanthanide extraction, appropriate phase disengagement, no appreciable deleterious effects due to the presence of impurities such as zirconium, excellent pH buffering, and no significant loss of organic phase

  12. Acanthamoeba encystment: multifactorial effects of buffers, biocides, and demulcents present in contact lens care solutions

    Directory of Open Access Journals (Sweden)

    Kovacs CJ

    2015-10-01

    Full Text Available Christopher J Kovacs, Shawn C Lynch, Marjorie J Rah, Kimberly A Millard, Timothy W Morris Bausch & Lomb Incorporated, Rochester, NY, USA Purpose: To determine whether agents which are purportedly capable of inducing encystment of Acanthamoeba can recapitulate the signal when tested in differing formulations. Methods: In accordance with the International Standard ISO 19045, Acanthamoeba castellanii ATCC 50370 trophozoites were cultured in antibiotic-free axenic medium, treated with test solutions, and encystment rates plus viability were measured via bright field and fluorescent microscopy. Test solutions included phosphate-buffered saline (PBS, borate-buffered saline, biguanide- and hydrogen peroxide (H2O2-based biocides, propylene glycol (PG and povidone (POV ophthalmic demulcents, and one-step H2O2-based contact lens disinfection systems. Results: Only PBS solutions with 0.25 ppm polyaminopropyl biguanide (PAPB and increasing concentrations of PG and POV stimulated A. castellanii encystment in a dose-dependent manner, whereas PBS solutions containing 3% H2O2 and increasing concentrations of PG and POV did not stimulate encystment. Borate-buffered saline and PBS/citrate solutions containing PG also did not stimulate encystment. In addition, no encystment was observed after 24 hours, 7 days, or 14 days of exposures of trophozoites to one-step H2O2 contact lens disinfection products or related solutions. Conclusion: The lack of any encystment observed when trophozoites were treated with existing or new one-step H2O2 contact lens care products, as well as when trophozoites were exposed to various related test solutions, confirms that Acanthamoeba encystment is a complex process which depends upon simultaneous contributions of multiple factors including buffers, biocides, and demulcents. Keywords: propylene glycol, contact lens care system, hydrogen peroxide disinfecting solution

  13. Free Rhodium (II) citrate and rhodium (II) citrate magnetic carriers as potential strategies for breast cancer therapy

    Science.gov (United States)

    2011-01-01

    Background Rhodium (II) citrate (Rh2(H2cit)4) has significant antitumor, cytotoxic, and cytostatic activity on Ehrlich ascite tumor. Although toxic to normal cells, its lower toxicity when compared to carboxylate analogues of rhodium (II) indicates Rh2(H2cit)4 as a promising agent for chemotherapy. Nevertheless, few studies have been performed to explore this potential. Superparamagnetic particles of iron oxide (SPIOs) represent an attractive platform as carriers in drug delivery systems (DDS) because they can present greater specificity to tumor cells than normal cells. Thus, the association between Rh2(H2cit)4 and SPIOs can represent a strategy to enhance the former's therapeutic action. In this work, we report the cytotoxicity of free rhodium (II) citrate (Rh2(H2cit)4) and rhodium (II) citrate-loaded maghemite nanoparticles or magnetoliposomes, used as drug delivery systems, on both normal and carcinoma breast cell cultures. Results Treatment with free Rh2(H2cit)4 induced cytotoxicity that was dependent on dose, time, and cell line. The IC50 values showed that this effect was more intense on breast normal cells (MCF-10A) than on breast carcinoma cells (MCF-7 and 4T1). However, the treatment with 50 μM Rh2(H2cit)4-loaded maghemite nanoparticles (Magh-Rh2(H2cit)4) and Rh2(H2cit)4-loaded magnetoliposomes (Lip-Magh-Rh2(H2cit)4) induced a higher cytotoxicity on MCF-7 and 4T1 than on MCF-10A (p rhodium (II) citrate-loaded maghemite nanoparticles and magnetoliposomes induced more specific cytotoxicity on breast carcinoma cells than on breast normal cells, which is the opposite of the results observed with free Rh2(H2cit)4 treatment. Thus, magnetic nanoparticles represent an attractive platform as carriers in Rh2(H2cit)4 delivery systems, since they can act preferentially in tumor cells. Therefore, these nanopaticulate systems may be explored as a potential tool for chemotherapy drug development. PMID:21443799

  14. Effect of buffer on the immune response to trivalent oral poliovirus vaccine in Bangladesh: a community based randomized controlled trial.

    Science.gov (United States)

    Chandir, Subhash; Ahamed, Kabir U; Baqui, Abdullah H; Sutter, Roland W; Okayasu, Hiromasa; Pallansch, Mark A; Oberste, Mark S; Moulton, Lawrence H; Halsey, Neal A

    2014-11-01

    Polio eradication efforts have been hampered by low responses to trivalent oral poliovirus vaccine (tOPV) in some developing countries. Since stomach acidity may neutralize vaccine viruses, we assessed whether administration of a buffer solution could improve the immunogenicity of tOPV. Healthy infants 4-6 weeks old in Sylhet, Bangladesh, were randomized to receive tOPV with or without a sodium bicarbonate and sodium citrate buffer at age 6, 10, and 14 weeks. Levels of serum neutralizing antibodies for poliovirus types 1, 2, and 3 were measured before and after vaccination, at 6 and 18 weeks of age, respectively. Serologic response rates following 3 doses of tOPV for buffer recipients and control infants were 95% and 88% (P=.065), respectively, for type 1 poliovirus; 95% and 97% (P=.543), respectively, for type 2 poliovirus; and 90% and 89% (P=.79), respectively, for type 3 poliovirus. Administration of a buffer solution prior to vaccination was not associated with statistically significant increases in the immune response to tOPV; however, a marginal 7% increase (P=.065) in serologic response to poliovirus type 1 was observed. NCT01579825. © The Author 2014. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  15. Formulation, Characterization and Physicochemical Evaluation of Potassium Citrate Effervescent Tablets

    Directory of Open Access Journals (Sweden)

    Fatemeh Fattahi

    2013-02-01

    Full Text Available Purpose: The aim of this study was to design and formulation of potassium citrate effervescent tablet for reduction of calcium oxalate and urate kidney stones in patients suffering from kidney stones. Methods: In this study, 13 formulations were prepared from potassium citrate and effervescent base in different concentration. The flowability of powders and granules was studied. Then effervescent tablets were prepared by direct compression, fusion and wet granulation methods. The prepared tablets were evaluated for hardness, friability, effervescent time, pH, content uniformity. To amend taste of formulations, different flavoring agents were used and then panel test was done by using Latin Square method by 30 volunteers. Results: Formulations obtained from direct compression and fusion methods had good flow but low hardness. Wet granulation improves flowability and other physicochemical properties such as acceptable hardness, effervescence time ≤3 minutes, pH<6, friability < 1%, water percentage < 0.5% and accurate content uniformity. In panel test, both of combination flavors; (orange - lemon and (strawberry - raspberry had good acceptability. Conclusion: The prepared tablets by wet granulation method using PVP solution had more tablet hardness. It is a reproducible process and suitable to produce granules that are compressed into effervescent tablets due to larger agglomerates.

  16. Value of gallium 67 citrate scintigraphy in ophthalmology

    International Nuclear Information System (INIS)

    Ivanez-Alloschery, Monique.

    1978-01-01

    For ophthalmologists scintigraphy appears as a simple method to detect endoocular or endoorbital abnormalities. However none of the many scintigraphic methods described seems reliable enough to be used alone. One of the latest isotopic explorations using gallium 67 citrate, a tracer considered tumour-tropic might be able to solve this problem. The aim of this work is to judge the value of the method in the diagnosis of malignant endoocular and endoorbital tumours on the basis of 24 anatomoclinical observations. It may be concluded from this study that ocular gallium 67 citrate scintigraphy, which gave no clearly positive results at all but some doubtful results in the case of endoocular tumours more than 5 mm in diameter, is to be rejected; fluorescein angiography and ocular echograhy provide more elements for an accurate etiological diagnosis. Orbital scintigraphy on the other hand seems to be a necessary complement to a tomodensitometric examination since both methods offer diagnostic information without systematic recurse to carotid arteriography or orbital phlebography, sometimes dangerous for the patient [fr

  17. Inkjet printing of silver citrate conductive ink on PET substrate

    Science.gov (United States)

    Nie, Xiaolei; Wang, Hong; Zou, Jing

    2012-11-01

    Direct synthesis of silver conductive film on PET substrate by inkjet printing silver citrate conductive ink was presented in this paper. This kind of conductive ink contained silver citrate as silver precursor, 1,2-diaminopropane as complex agent dissolving the silver salt and methanol and isopropanol as a media adjusting the viscosity and surface tension. The formation of silver-amine complex reduced the decomposition temperature from 180 °C to 135 °C, thus the ink could be cured at relatively low temperature. The film reached the lowest resistivity of 17 μΩ cm after cured at 150 °C for 50 min, 3.1 μΩ cm at 230 °C and possessed high reflection and excellent adhesive property. Electrical conductivity, surface morphology and composition were investigated by four-point probe method, scanning electron microscope (SEM) and energy dispersive X-ray spectroscopy (EDS). It is demonstrated how the cured condition affects the silver film. Moreover, radio-frequency identification (RFID) antenna was fabricated by inkjet printing, which opens up routes for the flexible electronics fabrication.

  18. Interactions between citrate-capped gold nanoparticles and polymersomes

    Science.gov (United States)

    Zhang, Xiaohan; Lopez, Anand; Liu, Yibo; Wang, Feng; Liu, Juewen

    2018-06-01

    Polymersomes are vesicles formed by self-assembled amphiphilic block copolymers. Polymersomes generally have better stability than liposomes and they have been widely used in making drug delivery vehicles. In this work, the interaction between two types of polymersomes and citrate-capped gold nanoparticles (AuNPs) was studied. The following two polymers: poly(2-methyloxazoline-b-dimethylsiloxane-b-2-methyloxazoline) (called P1) and poly(butadiene-b-ethylene oxide) (called P2) were respectively used to form polymersomes. While P1 only formed spherical vesicle structures, worm-like structures were also observed with P2 as indicated by cryo-TEM. Both polymersomes adsorbed AuNPs leading to their subsequent aggregation. A lower polymersome concentration produced more obvious aggregation of AuNPs as judged from the color change. Capping AuNPs with glutathione inhibited adsorption of AuNPs. Considering the surface property of the polymers, the interaction with AuNPs was likely due to van der Waals forces. P1 polymersomes encapsulated calcein stably and AuNPs did not induce leakage. The P1/AuNP complex was more efficiently internalized by HeLa cells compared to free P1 polymersomes, further indicating a stable adsorption under cell culture conditions. In summary, this work indicates citrate-capped AuNPs form stable adsorption complexes with these polymersomes and their interactions have been explored.

  19. Comparison of EDTA- and citric acid-enhanced phytoextraction of heavy metals in artificially metal contaminated soil by Typha angustifolia.

    Science.gov (United States)

    Muhammad, Dawood; Chen, Fei; Zhao, Jing; Zhang, Guoping; Wu, Feibo

    2009-08-01

    A pot experiment was conducted to study the performance of EDTA and citric acid (CA) addition in improving phytoextraction of Cd, Cu, Pb, and Cr from artificially contaminated soil by T. angustifolia. T. angustifolia showed the remarkable resistance to heavy metal toxicity with no visual toxic symptom including chlorosis and necrosis when exposed to metal stress. EDTA-addition significantly reduced plant height and biomass, compared with the control, and stunted plant growth, while 2.5 and 5 mM CA addition induced significant increases in root dry weight. EDTA, and 5 and 10 mM CA significantly increased shoot Cd, Pb, and Cr concentrations compared with the control, with EDTA being more effective. At final harvest, the highest shoot Cd, Cr, and Pb concentrations were recorded in the treatment of 5 mM EDTA addition, while maximal root Pb concentration was found at the 2.5 mM CA treatment. However, shoot Cd accumulation in the 10 mM CA treatment was 36.9% higher than that in 2.5 mM EDTA, and similar with that in 10 mM EDTA. Shoot Pb accumulation was lower in 10 mM CA than that in EDTA treatments. Further, root Cd, Cu, and Pb accumulation of CA treatments and shoot Cr accumulation in 5 or 10 mM CA treatments were markedly higher than that of control and EDTA treatments. The results also showed that EDTA dramatically increased the dissolution of Cu, Cr, Pb, and Cd in soil, while CA addition had less effect on water-soluble Cu, Cr, and Cd, and no effect on Pb levels. It is suggested that CA can be a good chelator candidate for T. angustifolia used for environmentally safe phytoextraction of Cd and Cr in soils.

  20. The effect of Emdogain and 24% EDTA root conditioning on periodontal healing of replanted dog's teeth.

    Science.gov (United States)

    Guzmán-Martínez, Nayelli; Silva-Herzog, Flores Daniel; Méndez, González Verónica; Martín-Pérez, Silvia; Cerda-Cristerna, Bernardino Isaac; Cohenca, Nestor

    2009-02-01

    Controversies still exist as for the regenerative role of enamel matrix derivatives and the need for removal of the periodontal ligament in replanted teeth. The purpose of this study was to evaluate the effect of Emdogain and 24% ethylenediamine tetraacetic acid (EDTA) root conditioning on periodontal healing of replanted dog's teeth. Teeth were extracted, endodontically treated and preconditioned as follows: group 1, Emdogain; group 2, Emdogain + EDTA and group 3, EDTA. Teeth were replanted after 30 min extraoral time, splinted for 15 days and animals sacrificed after 8 weeks of observation. Histological evaluation was performed using hematoxylin/eosin and Masson trichrome and results scored based on previously reported criteria for histological evaluation. Replacement root resorption was histologically diagnosed in all groups except in the negative control. A parametric analysis showed no statistically significant differences between experimental groups. Root preconditioning with Emdogain alone or in combination with 24% EDTA showed no evidence of regeneration of collagen fibers and consequently did not prevent the development of replacement root resorption on replanted dog's teeth.

  1. Effects of salinity and ethylenediamine tetra acetic acid (edta) on the ...

    African Journals Online (AJOL)

    In this study, the effects of the combined treatment of salinity and ethylenediamine tetra acetic acid (EDTA) on the germination of tomato seeds in Petri-dishes were compared to sole salinity. The treatments consisted of seven concentrations of sodium chloride (NaCL): 0 (control), 10, 50, 100, 250, 500 and 1000 mM.

  2. Ionic strength dependence of stability constants, complexation of Molybdenum(V I) with EDTA

    International Nuclear Information System (INIS)

    Zare, K.; Majlesi, K.; Teimoori, F.

    2002-01-01

    The stability constant of Mo (Vi) complexes with EDTA in aqueous solution has been determined by various authors using different techniques, but according to literature, no work has been reported on ionic strength dependence of these complexes. The present work describes the complexation of Mo (Vi) with EDTA in an ionic strength range of 0.1 to 1.0 moldm - 3 s odium perchlorate at 25 d ig C . The complexation of molybdenum (Vi) with EDTA was investigated in aqueous solution ranging in ph from 5 to 7 using UV spectrophotometric techniques. The composition of the complex was determined by the continuous variations method. It was shown that molybdenum (Vi) forms a 2:1 complex with EDTA of the type (MoO 3 ) 2 L - 4 a t ph =5.5 The parameters that define the dependence on ionic strength were analyzed with the aim of obtaining further information regarding to their variation as a function of the charges involved in the complex reaction. Moreover, a Debye-Huckel type equation makes it possible to estimate a stability constant at a fixed ionic strength when its value is known at another ionic media in the range of 0.1 3 . Therefore the evaluation may make a significant contribution solving many analytical and speciation problems

  3. Intraparticle diffusion of rare earths in porous ion exchanger rounding by EDTA solution

    International Nuclear Information System (INIS)

    Ling Daren; Xie Weije

    1991-01-01

    The self-diffusion of rate earth (RE) isotopes in porous cation exchangers with various radii or different pore structures rounding by EDTA solution was studied. The intraparticle effective diffusivity De was calculated by Boyd's method and Kataoka's bi-disperse pore model, and through further calculation the solid phase diffusivity Dg and macropore diffusivity Dp were also obtained. (author)

  4. Dissolution of root canal sealers in EDTA and NaOCl solutions.

    Science.gov (United States)

    Keleş, Ali; Köseoğlu, Mustafa

    2009-01-01

    Solutions of ethylenediaminetetraacetic acid (EDTA) and sodium hypochlorite (NaOCl) have been used as canal irrigants in endodontic treatment. The authors conducted a study to compare the ability of these solutions to dissolve sealers. The authors assessed the solubility of six sealers-calcium hydroxide, polyketone, zinc oxide-eugenol, silicone and two epoxy resins-in EDTA and two concentrations of NaOCl (2.5 percent and 5.0 percent). They immersed standardized samples (n = 5) of each sealer for two minutes and 10 minutes. They obtained the mean values of sealer dissolution in solutions by calculating the difference between the original preimmersion and postimmersion weights to determine the amount of sealer removed. They compared the values via factorial analysis of variance. They analyzed differences between the six sealers with respect to their solubility in EDTA or NaOCl solutions at two minutes and 10 minutes by using a one-way analysis of variance (P Polyketone and calcium hydroxide-based sealers were the most soluble sealers (P < .05). The results of this study indicate that during nonsurgical endodontic re-treatment, EDTA and NaOCl solutions used for removing smear layer aided in the retreatment by dissolving some root canal sealers.

  5. [Evaluation of compounding EDTA and citric acid on remediation of heavy metals contaminated soil].

    Science.gov (United States)

    Yin, Xue; Chen, Jia-Jun; Cai, Wen-Min

    2014-08-01

    As commonly used eluents, Na2EDTA (EDTA) and citric acid (CA) have been widely applied in remediation of soil contaminated by heavy metals. In order to evaluate the removal of arsenic, cadmium, copper, and lead in the contaminated soil collected in a chemical plant by compounding EDTA and CA, a series of stirring experiments were conducted. Furthermore, the changes in speciation distribution of heavy metals before and after washing were studied. The results showed that, adopting the optimal molar ratio of EDTA/CA (1:1), when the pH of the solution was 3, the stirring time was 30 min, the stirring rate was 150 r x min(-1) and the L/S was 5:1, the removal rates of arsenic, cadmium, copper and lead could reach 11.72%, 43.39%, 24.36% and 27.17%, respectively. And it was found that after washing, for arsenic and copper, the content of acid dissolved fraction rose which increased the percentage of available contents. Fe-Mn oxide fraction mainly contributed to the removal of copper. As for cadmium, the percentages of acid dissolved fraction, Fe-Mn oxide fraction and organic fraction also decreased. In practical projects, speciation changes would pose certain environmental risk after soil washing, which should be taken into consideration.

  6. Super water-absorbing new material from chitosan, EDTA and urea.

    Science.gov (United States)

    Narayanan, Abathodharanan; Dhamodharan, Raghavachari

    2015-12-10

    A new, super water-absorbing, material is synthesized by the reaction between chitosan, EDTA and urea and named as CHEDUR. CHEDUR is probably formed through the crosslinking of chitosan molecules (CH) with the EDTA-urea (EDUR) adduct that is formed during the reaction. CHEDUR as well as the other products formed in control reactions are characterized extensively. CHEDUR exhibits a very high water uptake capacity when compared with chitosan, chitosan-EDTA adduct, as well as a commercial diaper material. A systematic study was done to find the optimum composition as well as reaction conditions for maximum water absorbing capacity. CHEDUR can play a vital role in applications that demand the rapid absorption and slow release of water such as agriculture, as a three in one new material for the slow release of urea, water and other metal ions that can be attached through the EDTA component. The other potential advantage of CHEDUR is that it can be expected to degrade in soil based on its chitosan backbone. The new material with rapid and high water uptake could also find potential applications as biodegradable active ingredient of the diaper material. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. KINETICS OF THE OXIDATION OF FERROUS CHELATES OF EDTA AND HEDTA IN AQUEOUS-SOLUTION

    NARCIS (Netherlands)

    WUBS, HJ; BEENACKERS, AACM

    1993-01-01

    The kinetics of the reaction of oxygen with ferrous chelates of EDTA and HEDTA was studied in a stirred cell reactor under industrial conditions. The temperature was varied from 20 to 60-degrees-C and the concentration of the ferrous chelate ranged from 0 to 100 mol/m3. The initial pH was 7.5. Under

  8. Characteristics of mixed bacterial cultures degarding EDTA, isolated from Czech sources

    Czech Academy of Sciences Publication Activity Database

    Ivanova, V.; Šafaříková, Miroslava; Vassileva, A.; Tonkova, A.

    2004-01-01

    Roč. 51, č. 3 (2004), s. 306-311 ISSN 0477-0250. [ Food Science, Techniques and Technologies 2004. Plovdiv, 27.10.2004-29.10.2004] R&D Projects: GA AV ČR IBS6087204 Institutional research plan: CEZ:AV0Z6087904 Keywords : EDTA * biodegradation Subject RIV: EE - Microbiology, Virology

  9. Synthesis, Characterization, and Magnetic Properties of Pure and EDTA-Capped NiO Nanosized Particles

    Directory of Open Access Journals (Sweden)

    H. T. Rahal

    2017-01-01

    Full Text Available The effect of ethylenediaminetetraacetic acid (EDTA as a capping agent on the structure, morphology, optical, and magnetic properties of nickel oxide (NiO nanosized particles, synthesized by coprecipitation method, was investigated. Nickel chloride hexahydrate and sodium hydroxide (NaOH were used as precursors. The resultant nanoparticles were characterized by X-ray diffraction (XRD, transmission electron microscopy (TEM, and scanning electron microscopy (SEM. XRD patterns showed that NiO have a face-centered cubic (FCC structure. The crystallite size, estimated by Scherrer formula, has been found in the range of 28–33 nm. It is noticed that EDTA-capped NiO nanoparticles have a smaller size than pure nanoparticles. Thus, the addition of 0.1 M capping agent EDTA can form a nucleation point for nanoparticles growth. The optical and magnetic properties were investigated by Fourier transform infrared spectroscopy (FTIR and UV-vis absorption spectroscopy (UV as well as electron paramagnetic resonance (EPR and magnetization measurements. FTIR spectra indicated the presence of absorption bands in the range of 402–425 cm−1, which is a common feature of NiO. EPR for NiO nanosized particles was measured at room temperature. An EPR line with g factor ≈1.9–2 is detected for NiO nanoparticles, corresponding to Ni2+ ions. The magnetic hysteresis of NiO nanoparticles showed that EDTA capping recovers the surface magnetization of the nanoparticles.

  10. EDTA functionalized magnetic nanoparticle as a multifunctional adsorbent for Congo red dye from contaminated water

    Science.gov (United States)

    Sahoo, Jitendra Kumar; Rath, Juhi; Dash, Priyabrat; Sahoo, Harekrushna

    2017-05-01

    The present work reports the applicability of magnetite iron nanoparticles (Fe3O4) functionalized with ethylenediaminetetraacetic acid (EDTA) as an efficient adsorbent for the removal of Congo red (CR) dye from contaminated water. Magnetic nanoparticles (Fe3O4) are prepared by chemical precipitation method in which Fe2+ and Fe3+ salt from aqueous solution were reacted in presence of ammonia solution. The surface of Fe3O4 nanoparticle was first coated with (3-aminopropyl) triethoxy silane (APTES) by a salinization reaction and then linked with EDTA via reaction between -NH2 and -COOH to form well dispersed surface functionalised biocompatible magnetic nanoparticles. The obtained EDTA functionalized magnetic nanoparticles are characterized in terms of their morphological, XRD, BET surface area analysis, Fourier transform infrared spectroscopy (FT-IR) and Vibrating sample magnetometer (VSM). The adsorption of CR on Fe3O4-APTES-EDTA nanocomposite corresponds well to the Langmuir model and the Freundlich model respectively. The adsorption processes for CR followed the pseudo-second-order model.

  11. The separation of heavy lanthanons with NH4-EDTA as the eluent. The ionites comparison

    International Nuclear Information System (INIS)

    Frank, B.; Wolodkiewicz, W.

    1980-01-01

    Using two types of cation exchangers: Zerolit 225 x 8 and Wofatit KPS there was carried out the comparison of the ion exchange separation efficiency of the rare earth elements. The solution of NH 4 -EDTA with increasing pH gradient was used as the eluent. In these conditions no distinct differences in the separation of rare earth elements were found. (author)

  12. Impedance response characteristics of iron oxide interface in the EDTA solutions

    International Nuclear Information System (INIS)

    Sawa, Tosio; Higuchi, Shigeo; Kataoka, Ichiro; Ito, Hisao.

    1986-01-01

    The relationship between the dissolution and the surface conditions of Fe 3 O 4 were studied in the various conditions of EDTA solutions by means of the A · C impedance measurement. From the experimental results obtained, surface layer of Fe 3 O 4 electrode can be expressed with electrical equivalent circuit that have capacitance and reaction resistance in the electrical double layer. In the Na 2 SO 4 solution without occuring dissolution, reaction resistance was estimated as 314 kΩ · cm 2 and capacitance was 203 μF/cm 2 . In the EDTA solutions, reaction resistance decreases along with dissolution of Fe 3 O 4 . The factors to make decrease reaction resistance are EDTA concentration, pH and temperature of the solutions. In contrast with this, the factor to increase it is dissolved oxygen in the solutions. The reciprocal value of reaction resistance agrees well with the rate of dissolution. On the other hand, when the electrode potential was maintained under the cathodic polarization in the EDTA solutions, impedances of electrode surface showed the lower value than that in the immersion condition. And apparent resistance came near to 0 at the potential of -2.0 V in all the range of frequency. Fe 3 O 4 electrodes pretreated with the cathodic polarization exhibited the characteristic impedance response that were caused by the change of electrode surface and the deposites such as iron hydroxide. (author)

  13. A pulse radiolysis study of the formation and reactions of reduced metal EDTA complexes

    International Nuclear Information System (INIS)

    Buitenhuis, R.

    1977-01-01

    The construction of a computerized pulse radiolysis system with available means appropriate for the wavelength interval between 300 and 1000 nm is described. The investigation of the radiolysis of aqueous solutions of EDTA complexes in the presence of alcohols is discussed

  14. Effect of citric acid and EDTA on chromium and nickel uptake and translocation by Datura innoxia

    International Nuclear Information System (INIS)

    Jean, Liliane; Bordas, Francois; Gautier-Moussard, Cecile; Vernay, Philippe; Hitmi, Adnane; Bollinger, Jean-Claude

    2008-01-01

    EDTA and citric acid were tested to solubilize metals and enhance their uptake by Datura innoxia, chosen because of its ability to accumulate and tolerate metals. Two application modes were used on an industrial soil contaminated mainly by Cr and Ni. The results showed that citric acid was the most effective at increasing the uptake of Cr and EDTA for Ni. These results are consistent with the effectiveness of both chelants in solubilizing metals from the soil. The translocation factor (TF) of Ni was 1.6- and 6.7-fold higher than the control, respectively, for one and two applications of 1 mmol kg -1 EDTA. After two applications of 5 and 10 mmol kg -1 citric acid, the TF of Cr increased 2- and 3.5-fold relative to the control. Whatever the concentration, the application of EDTA modified the plant physiology significantly. For citric acid this was only observed with the highest dose (10 mmol kg -1 ). - Chelant effectiveness in increasing chromium and nickel uptake by Datura innoxia is the result of the increase in translocation versus negative effect on plant physiology

  15. Effect of sugarcane vinasse and EDTA on cadmium phytoextraction by two saltbush plants.

    Science.gov (United States)

    Eissa, Mamdouh A

    2016-05-01

    Although the use of saltbush plants in metal phytoremediation is well known, there is little information about the impact of sugarcane vinasse (SCV) and EDTA on metal uptake. Heavily cadmium-polluted soil (38 mg kg(-1) Cd) was used in pot and incubation experiments to investigate the Cd phytoextraction potential of wavy saltbush (Atriplex undulata) and quail saltbush (Atriplex lentiformis). EDTA at rates of 3, 6, and 10 mM kg(-1) soil and SCV at rates of 7, 15, and 30 mL kg(-1) soil were added to the polluted soil. The application of EDTA significantly (P = 0.002) reduced the growth of saltbush plants; on the other hand, SCV improved the growth. Both EDTA and SCV increased the availability and root-to-shoot transfer of Cd. The plants of A. lentiformis grown on the soil amended with the highest rate of SCV were able to remove 20.4 % of the total soil Cd during a period of 9 months. Based on the obtained results, it may be concluded that A. lentiformis and sugarcane vinasse could be more effective in the phytoextraction of Cd from the polluted soils.

  16. Chelate-assisted phytoextraction: effect of EDTA and EDDS on copper uptake by Brassica napus L.

    Directory of Open Access Journals (Sweden)

    TIJANA M. ZEREMSKI-ŠKORIĆ

    2010-09-01

    Full Text Available Chelate-assisted phytoextraction is proposed as an effective approach for the removal of heavy metals from contaminated soil through the use of high biomass plants. The aim of the present study was to compare the efficiency of the two chelators: EDTA and biodegradable EDDS in enhancing Cu uptake and translocation by Brassica napus L. grown on moderately contaminated soil and treated with increasing concentrations of EDTA or EDDS. Increasing amounts of EDDS caused serious growth suppression of B. napus and an increase in shoot metal concentrations. Growth suppression limited the actual amount of phytoextracted Cu at high concentrations of EDDS. The maximum amount of extracted Cu was achieved by the application of 8.0 and 4.0+4.0 mmol kg-1 EDDS. The shoot Cu concentrations after EDTA application were much lower than with EDDS at the same doses. According to these experiments, EDTA does not appear to be an efficient amendment if Cu phytoextraction with B. napus is considered but EDDS is.

  17. Plasma Calcium, Inorganic Phosphate and Magnesium During Hypocalcaemia Induced by a Standardized EDTA Infusion in Cows

    Directory of Open Access Journals (Sweden)

    Enemark JMD

    2001-06-01

    Full Text Available The intravenous Na2EDTA infusion technique allows effective specific chelation of circulating Ca2+ leading to a progressive hypocalcaemia. Methods previously used were not described in detail and results obtained by monitoring total and free ionic calcium were not comparable due to differences in sampling and analysis. This paper describes a standardized EDTA infusion technique that allowed comparison of the response of calcium, phosphorus and magnesium between 2 groups of experimental cows. The concentration of the Na2EDTA solution was 0.134 mol/l and the flow rate was standardized at 1.2 ml/kg per hour. Involuntary recumbency occurred when ionised calcium dropped to 0.39 – 0.52 mmol/l due to chelation. An initial fast drop of ionized calcium was observed during the first 20 min of infusion followed by a fluctuation leading to a further drop until recumbency. Pre-infusion [Ca2+] between tests does not correlate with the amount of EDTA required to induce involuntary recumbence. Total calcium concentration measured by atomic absorption remained almost constant during the first 100 min of infusion but declined gradually when the infusion was prolonged. The concentration of inorganic phosphate declined gradually in a fluctuating manner until recumbency. Magnesium concentration remained constant during infusion. Such electrolyte responses during infusion were comparable to those in spontaneous milk fever. The standardized infusion technique might be useful in future experimental studies.

  18. Immobilization of mixed bacterial cultures degrading EDTA and isolated from Bulgarian and Czech sources

    Czech Academy of Sciences Publication Activity Database

    Ivanova, V.; Tonkova, A.; Vassileva, A.; Šafaříková, Miroslava

    2004-01-01

    Roč. 51, č. 3 (2004), s. 312-317 ISSN 0477-0250. [Food Science, Techniques and Technologies 2004. Plovdiv, 27.10.2004-29.10.2004] R&D Projects: GA AV ČR IBS6087204 Institutional research plan: CEZ:AV0Z6087904 Keywords : EDTA * degradation * immobilization Subject RIV: EE - Microbiology, Virology

  19. Efektivitas KMK dan Na2 EDTA dalam Mengabsorbsi Paparan Merkuri pada Ikan Lele (Clarias batrachus

    Directory of Open Access Journals (Sweden)

    Tuti Hartati Siregar

    2010-12-01

    Full Text Available Penelitian ini dilaksanakan untuk mengamati efektivitas karboksimetil kitosan (KMK sebagai bahan pengkelat alami dan Na2 EDTA sebagai bahan pengkelat sintetis logam berat merkuri (Hg pada ikan lele. Ikan lele yang digunakan adalah jenis lele dumbo yang diperoleh dari Bogor. Ikan dipelihara dalam kolam berukuran 380 x 150 x 60 cm 3. Air kolam sebanyak 570 L yang berisi 200 ekor ikan lele dipapar dengan Hg 60–90 ppb secara bertahap selama 1 bulan dan penggantian air kolam dilakukan setiap minggu. Sebelum pemaparan dengan Hg dilakukan, ikan lele dikondisikan pada kolam percobaan selama 1 minggu. Pada minggu ke dua ikan dipapar merkuri 60 ppb, kemudian konsentrasi merkuri dinaikkan 15 ppb setiap minggu sampai dengan minggu ke empat. Pemaparan dihentikan setelah minggu ke empat. Setelah itu ikan dipanen kemudian difilet dan dikelat dengan cara direndam dalam larutan KMK dan Na 2EDTA masing-masing pada konsentrasi 0; 0,5; 1,0; dan 1,5% selama 0, 30, 60, dan 90 menit. Perendaman dalam air digunakan sebagai kontrol terhadap perlakuan tersebut. Setiap perlakuan diulang sebanyak 3 kali. Pengamatan yang dilakukan meliputi kandungan awal dan kandungan akhir Hg setelah perlakuan perendaman. Analisis dilakukan menggunakan instrumen AAS (Perkin Elmer tipe Aanalyst800. Hasil pengamatan menunjukkan bahwa perendaman dalam KMK dan Na 2 EDTA 0,5% selama 30 menit memberikan hasil yang terbaik, dan tidak ada perbedaan antara KMK dan Na2EDTA dalam fungsinya sebagai absorben logam berat.

  20. Role of CA-EDTA on the Synthesizing Process of Cerate-Zirconate Ceramics Electrolyte

    Directory of Open Access Journals (Sweden)

    Nur Athirah Abdullah

    2013-01-01

    Full Text Available The role of a combination between citric acid (CA and ethylenediaminetetra acetic acid (EDTA as chelating agents in preparation of BaCe0.54Zr0.36Y0.1O2.95 powder by a modified sol-gel method is reported. The precursor solutions were prepared from metal nitrate salts (M+, chelating agents (C, and ethylene glycol (EG at molar ratio of M+ : C : EG = 3 : 2 : 3. Chemical and phase transformation of samples during thermal decomposition were analyzed by thermogravimetric analysis (TGA and Fourier transform infrared (FTIR spectroscopy. TGA results show that the sample prepared by a combination of CA-EDTA exhibited the lowest thermal decomposition temperature, Ttd since there was no significant weight loss after 750°C. After calcined at 1100°C, the carbonates residue remained in the samples as proven by FTIR results. It was found that the used combination of CA-EDTA acts as a better combustion reagent to increase the reaction rate and influence the thermal decomposition behaviour compared to a single citric acid and EDTA, respectively. Apparently, calcination temperatures above 1100°C are needed to produce a pure perovskitic BaCe0.54Zr0.36Y0.1O2.95.

  1. Buffer protection in the installation phase

    International Nuclear Information System (INIS)

    Wimelius, Hans; Pusch, Roland

    2008-12-01

    The research and development of the design and construction of the SKB's repository for final disposal of spent reactor fuel is conducted along several paths ('lines'). Issues concerning the bedrock are dealt with in the 'rock line' and those related to buffer and backfill in deposition holes and tunnels are considered in the 'buffer line' and 'backfill line', respectively. These lines also deal with sub-activities that are coupled to several other lines. One of them includes development of techniques for protecting buffer blocks from moisture and water in the installation phase. Techniques and methods for placement and removal of the 'buffer protection sheet' are dealt with in the 'buffer line'. The removal is, however, considered as being part of the backfilling sequence. Since the performance of the sheet is of fundamental importance to the placement and function of the buffer it deserves particular attention. Thus, the removal of the rubber sheet that serves to protect the buffer blocks in the installation phase may be difficult and can cause significant problems that may require retrieval of already placed canister, buffer and backfill. These matters are in focus in the present report. Arrangements for protecting already placed buffer blocks from moist air and water have been tested in earlier large-scale experiments, i.e. the Prototype Repository project at Aespoe but the experience from them has called for more effective protection of the clay blocks as described in the present report. Focus is on the construction of foundation components at the bottom of the deposition holes required for establishing a tight seal between rock and buffer blocks, and on the protection sheet and arrangements for limiting water pressure on it. Special attention is paid to the drainage of the space between rock and protection sheet that is necessary for avoiding failure of the sheet and to systems for achieving this and for providing alarm signals if the allowed pressure is

  2. Buffer protection in the installation phase

    Energy Technology Data Exchange (ETDEWEB)

    Wimelius, Hans (Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden)); Pusch, Roland (Geodevelopment International AB, Lund (Sweden))

    2008-12-15

    The research and development of the design and construction of the SKB's repository for final disposal of spent reactor fuel is conducted along several paths ('lines'). Issues concerning the bedrock are dealt with in the 'rock line' and those related to buffer and backfill in deposition holes and tunnels are considered in the 'buffer line' and 'backfill line', respectively. These lines also deal with sub-activities that are coupled to several other lines. One of them includes development of techniques for protecting buffer blocks from moisture and water in the installation phase. Techniques and methods for placement and removal of the 'buffer protection sheet' are dealt with in the 'buffer line'. The removal is, however, considered as being part of the backfilling sequence. Since the performance of the sheet is of fundamental importance to the placement and function of the buffer it deserves particular attention. Thus, the removal of the rubber sheet that serves to protect the buffer blocks in the installation phase may be difficult and can cause significant problems that may require retrieval of already placed canister, buffer and backfill. These matters are in focus in the present report. Arrangements for protecting already placed buffer blocks from moist air and water have been tested in earlier large-scale experiments, i.e. the Prototype Repository project at Aespoe but the experience from them has called for more effective protection of the clay blocks as described in the present report. Focus is on the construction of foundation components at the bottom of the deposition holes required for establishing a tight seal between rock and buffer blocks, and on the protection sheet and arrangements for limiting water pressure on it. Special attention is paid to the drainage of the space between rock and protection sheet that is necessary for avoiding failure of the sheet and to systems for achieving

  3. Surface Water Protection by Productive Buffers

    DEFF Research Database (Denmark)

    Christen, Benjamin

    Vegetated riparian buffer zones are a widely recommended best management practice in agriculture for protecting surface and coastal waters from diffuse nutrient pollution. On the background of the EU funded research project NitroEurope (NEU; www.NitroEurope.eu), this study concentrates...... on the mitigation of nitrogen pollution in surface and groundwater, using riparian buffer zones for biomass production. The objectives are to map suitable areas for buffer implementation across the six NEU study landscapes, model tentative N-loss mitigation, calculate biomass production potential and economic...... designed for local conditions could be a way of protecting water quality attractive to many stakeholders....

  4. Neptunium speciation (complexation and redox behaviour) in aqueous citrate medium

    Energy Technology Data Exchange (ETDEWEB)

    Bonin, L.; Ansoborlo, E.; Moisy, Ph. [CEA Marcoule (France)

    2005-07-01

    Full text of publication follows: In the framework of the French Environmental Nuclear Toxicology programme, additional experiments related to the decorporation of actinides are planned. The lack of information on the neptunium behaviour within blood and the inefficiency of therapeutic treatments, led us to study the complexation of this element with basic anions. Within this purpose, the in vitro behaviour of Np{sup IV} and Np{sup V} in simple media simulating biological media was studied: blood plasma is one of the media of interest and it can be simulated, from a chemical point of view, by an aqueous solution with pH 7.4, containing ions such as citrate (1.6 10{sup -4} mol/L), lactate (1.5 10{sup -3} mol/L), CO{sub 3}{sup 2-} (2.5 10{sup -2} mol/L), PO{sub 4}{sup 3-} (1.1 10{sup -3} mol/L), SO{sub 4}{sup 2-} (3.3 10{sup -4} mol/L) and Cl{sup -} (9 10{sup -2} mol/L). This study was more specifically focused on the behaviour of neptunium with citrate ion, which is also a basic ligand to consider when one wishes to study the migration of actinides in the environment, since it exists in significant amounts in the ground due to its production by the plants. In order to determine the speciation of this system, spectrophotometry was more particularly used. Concerning the complexation phenomenon, the existence of several complexes of Np{sup V} with various acid-basic forms of the citrate anion was observed; regarding Np{sup IV}, two complexes, with 1:1 and 1:2 stoichiometry, have been respectively observed. The reactivity of Np{sup VI} is probably similar to the behaviour of U{sup VI}, which is reported in literature to form a complex with a 1:1 stoichiometry with the Cit{sup 3-}anion From the quantitative study of these equilibria, it has been possible to determine the values of various equilibrium constants. Concerning the stability of neptunium towards oxido-reduction, it was confirmed that Np{sup VI} was very quickly reduced to Np{sup V} by the citrate anions

  5. Transport of Sr 2+ and SrEDTA 2- in partially-saturated and heterogeneous sediments

    Science.gov (United States)

    Pace, M. N.; Mayes, M. A.; Jardine, P. M.; McKay, L. D.; Yin, X. L.; Mehlhorn, T. L.; Liu, Q.; Gürleyük, H.

    2007-05-01

    Strontium-90 has migrated deep into the unsaturated subsurface beneath leaking storage tanks in the Waste Management Areas (WMA) at the U.S. Department of Energy's (DOE) Hanford Reservation. Faster than expected transport of contaminants in the vadose zone is typically attributed to either physical hydrologic processes such as development of preferential flow pathways, or to geochemical processes such as the formation of stable, anionic complexes with organic chelates, e.g., ethylenediaminetetraacetic acid (EDTA). The goal of this paper is to determine whether hydrological processes in the Hanford sediments can influence the geochemistry of the system and hence control transport of Sr 2+ and SrEDTA 2-. The study used batch isotherms, saturated packed column experiments, and an unsaturated transport experiment in an undisturbed core. Isotherms and repacked column experiments suggested that the SrEDTA 2- complex was unstable in the presence of Hanford sediments, resulting in dissociation and transport of Sr 2+ as a divalent cation. A decrease in sorption with increasing solid:solution ratio for Sr 2+ and SrEDTA 2- suggested mineral dissolution resulted in competition for sorption sites and the formation of stable aqueous complexes. This was confirmed by detection of MgEDTA 2-, MnEDTA 2-, PbEDTA 2-, and unidentified Sr and Ca complexes. Displacement of Sr 2+ through a partially-saturated undisturbed core resulted in less retardation and more irreversible sorption than was observed in the saturated repacked columns, and model results suggested a significant reservoir (49%) of immobile water was present during transport through the heterogeneous layered sediments. The undisturbed core was subsequently disassembled along distinct bedding planes and subjected to sequential extractions. Strontium was unequally distributed between carbonates (49%), ion exchange sites (37%), and the oxide (14%) fraction. An inverse relationship between mass wetness and Sr suggested that

  6. Cd2+ and Zn2+ sorption on apatite in the presence of EDTA and humic substance

    Directory of Open Access Journals (Sweden)

    Viipsi K.

    2013-04-01

    Full Text Available The sorption of Cd2+ and Zn2+ on hydroxyapatite [HAP- Ca10(PO46(OH2] and fluorapatite [FAP- Ca10( PO46(F2] with different specific surface area and stoichiometry was investigated in batch experiments in the pH range 4 to 11 (25 ◦C; 0.1 M KNO3. The impact of different conditions was concerned: solution pH, the presence of complexing ligands (EDTA and humic substance and competing metal ions, as well as reaction kinetic and equilibrium conditions. To evaluate the reversibility of Cd2+ sorption onto HAP, desorption characteristics in water, Ca, EDTA, and HUM-solutions were determined. Additionally to solution analysis the surface composition of solid phases was analysed by X-Ray Photoelectron Spectroscopy XPS. The information from the chemical analyses was used to design an equilibration model that takes into account dissolution, surface potential, solution and surface complexation, as well as possible phase transformations. It was revealed that apatites effectively sorb Cd2+ and Zn2+ by ion exchange reactions on surface by formation of new surface phases. Using XPS the formation of a Me-enriched HAP surface was found, which was interpreted as the formation of a solid solution with the general formula: Ca8.4-xMex(HPO41.6(PO44.4(OH0.4. In a binary solution (Cd+Zn the competition of metals reduced individual sorbed amount compared with the single component solutions but the total adsorption maximum was approximately constant. The presence of EDTA reduces the metal sorption on apatite due to [CdEDTA]2- and [ZnEDTA]2- complexes and increases apatite solubility due to [CaEDTA]2- complex formation. The dissolved humic substance was bound on apatite in suspensions but the amount of Cd2+ bound was not changed. The results showed that the solution pH and the presence of complexing ligands have a significant effect on heavy metal sorption on apatite and must be considered if apatites are used as remediation agent. The proposed model can be used to predict

  7. 78 FR 34338 - Citric Acid and Certain Citrate Salts From Canada: Preliminary Results of Antidumping Duty...

    Science.gov (United States)

    2013-06-07

    ... DEPARTMENT OF COMMERCE International Trade Administration [A-122-853] Citric Acid and Certain... on citric acid and certain citrate salts (citric acid) from Canada. The period of review (POR) is May... INFORMATION: Scope of the Order The merchandise covered by this order is citric acid and certain citrate salts...

  8. 76 FR 34044 - Citric Acid and Certain Citrate Salts From Canada: Final Results of Antidumping Duty...

    Science.gov (United States)

    2011-06-10

    ... DEPARTMENT OF COMMERCE International Trade Administration [A-122-853] Citric Acid and Certain... the antidumping duty order on citric acid and certain citrate salts (citric acid) from Canada. The... order on citric acid from Canada. See Citric Acid and Certain Citrate Salts From Canada: Preliminary...

  9. 78 FR 34648 - Citric Acid and Certain Citrate Salts: Preliminary Results of Countervailing Duty Administrative...

    Science.gov (United States)

    2013-06-10

    ... citric acid and citrate salts from the People's Republic of China for the period January 1, 2011, through... and Certain Citrate Salts from the People's Republic of China: Notice of Countervailing Duty Order, 74... subsidy, i.e., a government-provided financial contribution that gives rise to a benefit to the recipient...

  10. Evaluating the efficacy of citrate anticoagulation during CRRT in cardiac patients

    Directory of Open Access Journals (Sweden)

    А. М. Караськов

    2015-10-01

    Full Text Available Systemic anticoagulation during renal replacement therapy in cardiac patients increases the risk of postoperative complications. Citrate anticoagulation is a promising alternative. The objective of our study was to evaluate the efficacy of citrate anticoagulation and its influence on the parameters of hemostasis and complications.

  11. Pathogenic mutations of the human mitochondrial citrate carrier SLC25A1 lead to impaired citrate export required for lipid, dolichol, ubiquinone and sterol synthesis.

    Science.gov (United States)

    Majd, Homa; King, Martin S; Smith, Anthony C; Kunji, Edmund R S

    2018-01-01

    Missense mutations of the human mitochondrial citrate carrier, encoded by the SLC25A1 gene, lead to an autosomal recessive neurometabolic disorder characterised by neonatal-onset encephalopathy with severe muscular weakness, intractable seizures, respiratory distress, and lack of psychomotor development, often resulting in early death. Here, we have measured the effect of all twelve known pathogenic mutations on the transport activity. The results show that nine mutations abolish transport of citrate completely, whereas the other three reduce the transport rate by >70%, indicating that impaired citrate transport is the most likely primary cause of the disease. Some mutations may be detrimental to the structure of the carrier, whereas others may impair key functional elements, such as the substrate binding site and the salt bridge network on the matrix side of the carrier. To understand the consequences of impaired citrate transport on metabolism, the substrate specificity was also determined, showing that the human citrate carrier predominantly transports citrate, isocitrate, cis-aconitate, phosphoenolpyruvate and malate. Although D-2- and L-2 hydroxyglutaric aciduria is a metabolic hallmark of the disease, it is unlikely that the citrate carrier plays a significant role in the removal of hydroxyglutarate from the cytosol for oxidation to oxoglutarate in the mitochondrial matrix. In contrast, computer simulations of central metabolism predict that the export of citrate from the mitochondrion cannot be fully compensated by other pathways, restricting the cytosolic production of acetyl-CoA that is required for the synthesis of lipids, sterols, dolichols and ubiquinone, which in turn explains the severe disease phenotypes. Copyright © 2017. Published by Elsevier B.V.

  12. [Effect of glucose and lactose on the utilization of citrate by Lactobacillus casei subsp. rhamnosus ATCC 7469].

    Science.gov (United States)

    Benito de Cárdenas, I L; Medina, R; Oliver, G

    1992-01-01

    The utilization of citrate by Lactobacillus casei subsp. rhamnosus ATCC 7469 in a complex medium containing glucose, lactose or citrate was investigated, as an approach to the question of the transport of this acid and the possible relationship with the production of flavour compounds (diacetyl and acetoin). This lactobacillus uses citrate as an energy source in the absence of carbohydrates. External pH and growth increases when citrate is added to complex medium. The presence of citrate does not affect glucose uptake. L. casei ATCC 7469 possibly uses a transport system for citrate utilization, and citrate uptake seems to be under glucose or lactose control. Lactose only inhibits the entrance of citrate at high concentration while the utilization of this acid was negatively regulated by low glucose concentration.

  13. Radiolabeled porphyrin versus gallium-67 citrate for the detection of human melanoma in athymic mice

    International Nuclear Information System (INIS)

    Maric, N.; Chan, S. Ming; Hoffer, P.B.; Duray, P.

    1987-01-01

    We performed the biodistribution and imaging studies of 111 In and 67 Ga labeled tetra(4-N-methylpyridyl) porphine, (T4NMPYP), and compared it to that of 67 Ga citrate in athymic mice bearing a human melanoma xenograft. The biodistribution results of both 111 In and 67 Ga labeled T4NMPYP (3, 6, 24, and 48 hours) were similar but differed from that of 67 Ga citrate (48 hours). The optimum tumor uptake of both radiolabeled porphyrins was at 6 hours postinjection and was lower than the tumor uptake of 67 Ga citrate at 48 hours postinjection. Kidney was the only organ showing higher uptake of radiolabeled porphyrin compared to that of 67 Ga citrate. The imaging studies performed with 111 In T4NMPYP and 67 Ga citrate correspond to the biodistribution results. Osteomyelitis present in one mouse showed good localization of 111 In T4NMPYP. 15 refs., 3 figs., 5 tabs

  14. Buffer sizing for multi-hop networks

    KAUST Repository

    Shihada, Basem; Jamshaid, Kamran

    2014-01-01

    domain according to a simple division or according to a cost function taking into account a distance of the communications link from the source and destination. The network may be monitored and the cumulative buffer size recalculated and redistributed

  15. Moisture Buffer Value of Building Materials

    DEFF Research Database (Denmark)

    Rode, Carsten; Peuhkuri, Ruut; Time, Berit

    2007-01-01

    When building materials are in contact with indoor air they have some effect to moderate the variations of indoor humidity in occupied buildings. But so far there has been a lack of a standardized quantity to characterize the moisture buffering capability of materials. It has been the objective o...... is a test protocol which expresses how materials should be tested for determination of their Moisture Buffer Value. Finally, the paper presents some of the results of a Round Robin Test on various typical building materials that has been carried out in the project....... of a recent Nordic project to define such a quantity, and to declare it in the form of a NORDTEST method. The Moisture Buffer Value is the figure that has been developed in the project as a way to appraise the moisture buffer effect of materials, and the value is described in the paper. Also explained...

  16. Calculating Buffer Zones: A Guide for Applicators

    Science.gov (United States)

    Buffer zones provide distance between the application block (i.e., edge of the treated field) and bystanders, in order to control pesticide exposure risk from soil fumigants. Distance requirements may be reduced by credits such as tarps.

  17. Buffer Strips for Riparian Zone Management

    National Research Council Canada - National Science Library

    1991-01-01

    This study provides a review of technical literature concerning the width of riparian buffer strips needed to protect water quality and maintain other important values provided by riparian ecosystem...

  18. Lucas Heights buffer zone: plan of management

    International Nuclear Information System (INIS)

    1986-01-01

    This plan is being used by the Commission as a guide for its management of the Lucas Heights buffer zone, which is essentially a circular area having a 1-6 km radius around the HIFAR reactor. Aspects covered by this plan include past uses, current use, objectives for buffer zone land management, emergency evacuation, resource conservation, archaeology, fire, access, rehabilitation of disturbed areas, resource management and plan implementation

  19. Comparative genomics and transcriptome analysis of Aspergillus niger and metabolic engineering for citrate production

    Science.gov (United States)

    Yin, Xian; Shin, Hyun-dong; Li, Jianghua; Du, Guocheng; Liu, Long; Chen, Jian

    2017-01-01

    Despite a long and successful history of citrate production in Aspergillus niger, the molecular mechanism of citrate accumulation is only partially understood. In this study, we used comparative genomics and transcriptome analysis of citrate-producing strains—namely, A. niger H915-1 (citrate titer: 157 g L−1), A1 (117 g L−1), and L2 (76 g L−1)—to gain a genome-wide view of the mechanism of citrate accumulation. Compared with A. niger A1 and L2, A. niger H915-1 contained 92 mutated genes, including a succinate-semialdehyde dehydrogenase in the γ-aminobutyric acid shunt pathway and an aconitase family protein involved in citrate synthesis. Furthermore, transcriptome analysis of A. niger H915-1 revealed that the transcription levels of 479 genes changed between the cell growth stage (6 h) and the citrate synthesis stage (12 h, 24 h, 36 h, and 48 h). In the glycolysis pathway, triosephosphate isomerase was up-regulated, whereas pyruvate kinase was down-regulated. Two cytosol ATP-citrate lyases, which take part in the cycle of citrate synthesis, were up-regulated, and may coordinate with the alternative oxidases in the alternative respiratory pathway for energy balance. Finally, deletion of the oxaloacetate acetylhydrolase gene in H915-1 eliminated oxalate formation but neither influence on pH decrease nor difference in citrate production were observed. PMID:28106122

  20. Buffer regulation of calcium puff sequences

    International Nuclear Information System (INIS)

    Fraiman, Daniel; Dawson, Silvina Ponce

    2014-01-01

    Puffs are localized Ca 2+ signals that arise in oocytes in response to inositol 1,4,5-trisphosphate (IP 3 ). They are the result of the liberation of Ca 2+ from the endoplasmic reticulum through the coordinated opening of IP 3 receptor/channels clustered at a functional release site. The presence of buffers that trap Ca 2+ provides a mechanism that enriches the spatio–temporal dynamics of cytosolic calcium. The expression of different types of buffers along the cell's life provides a tool with which Ca 2+ signals and their responses can be modulated. In this paper we extend the stochastic model of a cluster of IP 3 R-Ca 2+ channels introduced previously to elucidate the effect of buffers on sequences of puffs at the same release site. We obtain analytically the probability laws of the interpuff time and of the number of channels that participate of the puffs. Furthermore, we show that under typical experimental conditions the effect of buffers can be accounted for in terms of a simple inhibiting function. Hence, by exploring different inhibiting functions we are able to study the effect of a variety of buffers on the puff size and interpuff time distributions. We find the somewhat counter-intuitive result that the addition of a fast Ca 2+ buffer can increase the average number of channels that participate of a puff. (paper)

  1. Buffer regulation of calcium puff sequences.

    Science.gov (United States)

    Fraiman, Daniel; Dawson, Silvina Ponce

    2014-02-01

    Puffs are localized Ca(2 +) signals that arise in oocytes in response to inositol 1,4,5-trisphosphate (IP3). They are the result of the liberation of Ca(2 +) from the endoplasmic reticulum through the coordinated opening of IP3 receptor/channels clustered at a functional release site. The presence of buffers that trap Ca(2 +) provides a mechanism that enriches the spatio-temporal dynamics of cytosolic calcium. The expression of different types of buffers along the cell's life provides a tool with which Ca(2 +) signals and their responses can be modulated. In this paper we extend the stochastic model of a cluster of IP3R-Ca(2 +) channels introduced previously to elucidate the effect of buffers on sequences of puffs at the same release site. We obtain analytically the probability laws of the interpuff time and of the number of channels that participate of the puffs. Furthermore, we show that under typical experimental conditions the effect of buffers can be accounted for in terms of a simple inhibiting function. Hence, by exploring different inhibiting functions we are able to study the effect of a variety of buffers on the puff size and interpuff time distributions. We find the somewhat counter-intuitive result that the addition of a fast Ca(2 +) buffer can increase the average number of channels that participate of a puff.

  2. 77 FR 47370 - Citric Acid and Certain Citrate Salts from the People's Republic of China: Intent To Rescind...

    Science.gov (United States)

    2012-08-08

    ... DEPARTMENT OF COMMERCE International Trade Administration [C-570-938] Citric Acid and Certain... citric acid and certain citrate salts from the People's Republic of China.\\1\\ On May 31, 2012, we... order includes all grades and granulation sizes of citric acid, sodium citrate, and potassium citrate in...

  3. Rôle modeste du citrate comme transporteur d'acétyl-CoA chez l'animal vivant.

    Science.gov (United States)

    Rous, S

    1971-02-09

    2,4-(14) C-Citrate incorporated to a far greater extent than 1,5-(14) C-citrate into liver, carcass or adipose tissue fatty acids of living mice. This finding excludes the possibility that the acetyl units emerge from the mitochondria in the form of citrate.

  4. Determinação do teor de edta remanescente em soluções de limpeza de equipamentos industriais Determination of edta content in cleaning solutions after their use in industrial equipaments

    Directory of Open Access Journals (Sweden)

    Arnaldo Antonio Rodella

    2007-08-01

    Full Text Available Cleaning solutions containing EDTA are widely employed to remove incrustation despite of the costs involved. The free content of EDTA in commercial solutions may be determined by mixing an aliquot to ammonium oxalate and using a standard calcium solution as titrant. The end-point is detected by the formation of insoluble calcium oxalate after all EDTA is complexed. A system for turbidimetric detection of the end-point was envisaged to substitute the visual detection, which impaired the analyses of dark samples. The proposed method was tested with real samples and good accuracy and precision was obtained.

  5. Comparison of Three Analytical Methods for Separation of Mineral and Chelated Fraction from an Adulterated Zn-EDTA Fertilizer

    International Nuclear Information System (INIS)

    Khan, M.S.; Qazi, M.A.; Khan, N.A.; Mian, S.M.; Ahmed, N.; Ahmed, N.

    2013-01-01

    Summary: Different analytical procedures are being employed in the world to quantify the chelated portion in a Zn-EDTA fertilizer. Agriculture Department, Government of the Punjab is following Shahid's analytical method in this regard. This method is based on Ion-chromatography (IC) that separates the mineral zinc (Zn) from an adulterated Zn-EDTA fertilizer sample i.e. mixture of mineral and chelated Zn fractions. To find out its effectiveness and suitability, this comparative study was carried out by analyzing adulterated, non-adulterated Zn-EDTA standard and Zn-EDTA samples taken from market in thrice following three methods namely Shahid's (IC) analytical method, Atomic Absorption Spectrophotometric (AAS) method based on the principle of precipitating the mineral Zn fraction at high pH value by using alkali solution of suitable concentration and analysis of filtrate containing only chelated fraction and Association of Official Analytical Chemists (AOAC) method FM-841 respectively. Adulterated Zn-EDTA samples were prepared by mixing of known quantity of mineral Zn with chelated Zn-EDTA standard. The results showed that Shahid's analytical method and AAS method, both successfully estimated the chelated fraction. The AOAC FM-841 method was insensitive to put a ceiling on the mineral fraction hence did not furnish the reliable results. The Shahid's analytical method was selected being equallyeffective to produce reliable results both for solid and liquid Zn-EDTA samples. The AAS method was comparable in only liquid samples. (author)

  6. Preparation of 99mTc-EDTA-MN and Its Bioimaging in Mouse

    Directory of Open Access Journals (Sweden)

    Yongshuai QI

    2015-07-01

    Full Text Available Background and objective Hypoxia is an important biological characteristics of solid tumor, it is not sensitive to radiotherapy and chemotherapy for which is the presence of hypoxic cell, thus increasing their resistance to conventional radiotherapy and chemotherapy, therefore, the detection of hypoxia degree of tumor tissue is of great significance. The hypoxia imaging of nuclear medicine can reflect the degree of tissue hypoxia, which can selectively retained on the hypoxic cells or tissues, including nitroimidazole and non nitroimidazole; the nitroimidazole is widely and deeply researched as hypoxic celles developer in China and abroad at present. The research about application of radionuclide labelled technique has clinical application value to develop the hypoxia imaging agent EDTA-MN complexes which was labeled. To study the feasibility of 99mTc by direct labeling method, the radiochemical properties evaluation of 99mTc-EDTA-MN, and observe the distribution characteristics of 99mTc radiolabeled EDTA-MN in the xenograft lung cancer nude mice bearing non-small cell lung cancer cell (A549, and provide experimental evidence for its further research and application. Methods The radiolabeling of EDTA-MN with 99mTc was performed with direct labeling method, respectively, on the reaction dosage (10 mg, 5 mg, 2 mg, stannous chloride dosage (8 mg/mL, 4 mg/mL, 2 mg/mL, mark system pH (2, 4, 5, 6 one by one test, using orthogonal design analysis, to find the optimal labeling conditions. Labelling rate, radiochemical purity, lipid-water partition coefficient and in vitro stability in normal saline (NS were determined by TLC and HPLC, and the preliminary study on the distribution of 99mTc-EDTA-MN in nude mice. Results The labeling rate of 99mTc-EDTA-MN with the best labeling conditions was (84.11±2.83%, and the radiochemical purity was higher than 90% by HPLC purification, without any notable decomposition at room temperature over a period of 12 h. The

  7. Low noise buffer amplifiers and buffered phase comparators for precise time and frequency measurement and distribution

    Science.gov (United States)

    Eichinger, R. A.; Dachel, P.; Miller, W. H.; Ingold, J. S.

    1982-01-01

    Extremely low noise, high performance, wideband buffer amplifiers and buffered phase comparators were developed. These buffer amplifiers are designed to distribute reference frequencies from 30 KHz to 45 MHz from a hydrogen maser without degrading the hydrogen maser's performance. The buffered phase comparators are designed to intercompare the phase of state of the art hydrogen masers without adding any significant measurement system noise. These devices have a 27 femtosecond phase stability floor and are stable to better than one picosecond for long periods of time. Their temperature coefficient is less than one picosecond per degree C, and they have shown virtually no voltage coefficients.

  8. Redistribution of fractions of zinc, cadmium, nickel, copper, and lead in contaminated calcareous soils treated with EDTA.

    Science.gov (United States)

    Jalali, Mohsen; Khanlari, Zahra V

    2007-11-01

    Effect of ethylene diamine tetraacetic acid (EDTA) on the fractionation of zinc (Zn), cadmium (Cd), nickel (Ni), copper (Cu), and lead (Pb) in contaminated calcareous soils was investigated. Soil samples containing variable levels of contamination, from 105.9 to 5803 mg/kg Zn, from 2.2 to 1361 mg/kg Cd, from 31 to 64.0 mg/kg Ni, from 24 to 84 mg/kg Cu, and from 109 to 24,850 mg/kg Pb, were subjected to EDTA treatment at different dosages of 0, 1.0, and 2.0 g/kg. Metals in the incubated soils were fractionated after 5 months by a sequential extraction procedure, in which the metal fractions were experimentally defined as exchangeable (EXCH), carbonate (CARB), Mn oxide (MNO), Fe oxide (FEO), organic matter (OM), and residual (RES) fractions. In contaminated soils without EDTA addition, Zn, Ni, Cu, and Pb were predominately present in the RES fraction, up to 60.0%, 32.3%, 41.1%, and 36.8%, respectively. In general, with the EDTA addition, the EXCH and CARB fractions of these metals increased dramatically while the OM fraction decreased. The Zn, Ni, Cu, and Pb were distributed mostly in RES, OM, FEO, and CARB fractions in contaminated soils, but Cd was found predominately in the CARB, MNO, and RES fractions. The OM fraction decreased with increasing amounts of EDTA. In the contaminated soils, EDTA removed some Pb, Zn, Cu, and Ni from MNO, FEO, and OM fractions and redistributed them into CARB and EXCH fractions. Based on the relative percent in the EXCH and CARB fractions, the order of solubility was Cd > Pb > Ni > Cu > Zn for contaminated soils, before adding of EDTA, and after adding of EDTA, the order of solubility was Pb > Cd > Zn > Ni > Cu. The risk of groundwater contamination will increase after applying EDTA and it needed to be used very carefully.

  9. [Perinatal clomiphene citrate treatment changes sexual orientations of male mice].

    Science.gov (United States)

    He, Feng-Qin; Zhang, Heng-Rui

    2013-10-01

    Perinatal period and adolescence are critical for brain development, which is the biological basis of an individual's sexual orientation and sexual behavior. In this study, animals were divided into two groups and their sexual orientations were observed: one group experienced drug treatments during the perinatal period, and the other group was castrated at puberty. The results showed that estradiol treatment had no effect on mature male offspring's sexual orientations, but 9 days and 14 days of clomiphene citrate treatment significantly increased the chance of homosexuality and effeminized behavior. In addition, the sexual orientation of mature normal male offspring, which were castrated when they were 21 days old,was not significant different from the control animals. These findings suggest that the inhibition of perinatal estrogen activities could suppress individual male-typical responses, enhance female-typical responses and induce homosexual orientations. Moreover, the masculinizing effects of estrogen were more obvious during perinatal period than adolescence.

  10. Heterotopic pregnancy following induction of ovulation with clomiphene citrate.

    Science.gov (United States)

    Ghandi, Sedigheh; Ahmadi, Raheleh; Fazel, Mahmoud

    2011-01-01

    Although heterotopic gestation is common in assisted reproductive techniques, it is very rare in natural conception and clomiphene induced pregnancy. Diagnosis and appropriate intervention of heterotopic pregnancy requires a high index of suspicious. In this paper a case of heterotopic pregnancy in a 30-year old woman with hemoperitoneum from ruptured tubal pregnancy with live intrauterine gestation at 9 weeks of gestation is reported. This case suggests that a heterotopic pregnancy must always be considered particularly after the induction of ovulation by clomiphene citrate or assisted reproductive technology. Every clinician treating women of reproductive age should keep this diagnosis in mind. It also demonstrates that early diagnosis is essential in order to salvage the intrauterine pregnancy and avoid maternal morbidity and mortality.

  11. Heterotopic pregnancy following induction of ovulation with clomiphene citrate

    Directory of Open Access Journals (Sweden)

    Sedigheh Ghandi

    2011-01-01

    Full Text Available Background: Although heterotopic gestation is common in assisted reproductive techniques, it is very rare in natural conception and clomiphene induced pregnancy. Diagnosis and appropriate intervention of heterotopic pregnancy requires a high index of suspicious.Case: In this paper a case of heterotopic pregnancy in a 30-year old woman with hemoperitoneum from ruptured tubal pregnancy with live intrauterine gestation at 9 weeks of gestation is reported.Conclusion: This case suggests that a heterotopic pregnancy must always be considered particularly after the induction of ovulation by clomiphene citrate or assisted reproductive technology. Every clinician treating women of reproductive age should keep this diagnosis in mind. It also demonstrates that early diagnosis is essential in order to salvage the intrauterine pregnancy and avoid maternal morbidity and mortality

  12. Pre-process desilication of wheat straw with citrate

    DEFF Research Database (Denmark)

    Le, Duy Michael; Sorensen, Hanne R.; Meyer, Anne S.

    2017-01-01

    in the residual biomass and treatment temperature was observed up to 170 degrees C, yielding a Si removal of up to 97.7%. This high Si removal came at the expense of a low mass yield (down to 45%) in the insoluble lignocellulosic fraction. Optimum process conditions for high Si removal and high total mass yield...... were: 100mM sodium citrate, 130 degrees C, 60 min, 2% w/v solids, and pH of similar to 6.5 during extraction. Using the proposed process conditions, silica removal of up to 77% was achieved with a mass yield of 72.8%. This Si removal from the insoluble lignocellulosic fraction did not affect...

  13. The effect of clomiphene-citrate on broody turkey hens.

    Science.gov (United States)

    Robinzon, B; Shafir, Z; Perek, M; Snapir, N

    1984-11-01

    The effect of clomiphene-citrate (CC) on broody turkey hens was examined in three experiments. Turkey hens were categorized as broody if found in the laying nest during 6 successive checks per day, if they were reluctant to leave the nest for a period of 24 hr or more, if they had ruffled feathers, and if their cloacal orifices were contracted so as to prevent vaginal exposure by abdominal massage during artificial insemination. In each experiment, 20 hens, selected as broody from commercial breeding flocks, were treated; half were treated with CC at a dosage of 6 mg/kg body weight/day (per os) for 5 consecutive days, and the rest (control) received parallel treatment with a placebo (CaCO3). In all experiments, the CC administration alleviated brooding behavior and increased egg production.

  14. Effect of Nb on barium titanate prepared from citrate solutions

    Directory of Open Access Journals (Sweden)

    Stojanović Biljana D.

    2002-01-01

    Full Text Available The influence of the addition of dopants on the microstructure development and electrical properties of BaTiO3 doped with 0.2, 0.4, 0.6, 0.8 mol% of Nb and 0.01 mol% of Mn based compounds was studied. Doped barium titanate was prepared using the polymeric precursor method from citrate solutions. The powders calcined at 700°C for 4 hours were analysed by infrared (IR spectroscopy to verify the presence of carbonates, and by X-ray diffraction (XRD for phase formation. The phase composition, microstructure and dielectric properties show a strong dependence on the amount of added niobium.

  15. Chromium-51-EDTA clearance in adults with a single-plasma sample.

    Science.gov (United States)

    Mårtensson, J; Groth, S; Rehling, M; Gref, M

    1998-12-01

    In 1996, a committee on renal clearance recommended a mean sojourn time-based methodology for single-sample determination of plasma clearance of 99mTc-diethylenetriamine pentaacetic acid (DTPA) to be used on adults if the patient's glomerular filtration rate (GFR) is suspected to be >30 ml/min. The main purpose of this study was to derive a mean sojourn time-based formula for calculation of 51Cr-ethylenediamine tetraacetic acid (EDTA) clearance in adults. Two groups of patients with 51Cr-EDTA clearance (Cl) between 16 and 172 ml/min were studied. In Group I (n = 46), reference Cl was determined as a multiplasma sample, single-injection method (ClSM). Sixteen blood samples were drawn from 0 until 5 hr after a single intravenous injection of 51Cr-EDTA. In Group II (n = 1046), reference Cl was determined by the Brøchner-Mortensen four-sample clearance method (ClBM). The plasma time-activity curves of Group I were used to derive two mean sojourn time-based formulas (Formulas 1 and 2) for calculation of a single-sample clearance. Formula 1 was derived from the entire time-activity curve, whereas the derivation of Formula 2 used only the final slope of the time-activity curve. The accuracy of the two formulas and the Christensen and Groth 99mTc-DTPA formula was tested on Group II. Chromium-51-EDTA Cl calculated by Formula 1 was almost identical to the Cl calculated by the reference Cl method (r = 0.982; SDdiff = 5.82 ml/min). Both 51Cr-EDTA Cl calculated by Formula 2 and by the 99mTc-DTPA formula showed close correlation with the reference method (r = 0.976, r = 0.985, respectively) but systematically overestimated GFR for the whole range of clearance values by 3.5 and 3.2 ml/min (ptime methodology. The determination is marginally more accurate (ptime-activity curve than from only the final slope. The single-sample formula derived for determination of 99mTc-DTPA Cl tends slightly to overestimate GFR if used to calculate 51Cr-EDTA Cl.

  16. PENGARUH PENGOLAHAN DAN PENAMBAHAN Na2EDTA PADA TERIGU FORTIFIKASI TERHADAP KETERSEDIAAN BIOLOGIS SENG

    Directory of Open Access Journals (Sweden)

    Estu Nugroho

    2014-05-01

    Full Text Available ABSTRACTThe objective of this research was to analyze changes in bioavailability of zinc (Zn caused by addition of Na2EDTA and processing of fortified wheat flour. Bioavailability of zinc was tested by in vitro method as a simulation of human digestive track. The result showed that there was no significant difference in the bioavailability of zinc on wheat flour which is processed by frying (donuts, steaming (steamed bun, and baking (bread (p>0.05. However, there was a tendency to increase the bioavailability of wheat flour processed by frying (donuts and baking (bread when compared to the raw dough. Raw dough had bioavailability of zinc 13.29%, after frying (donut increase to 14.72%, and after baking (bread increase to 17.06%. The addition of Na2EDTA also did not increase bioavailability of zinc significantly for the three types of processing (p>0.05, despite increased bioavailability of zinc on the donuts by 4.67%.Keywords: bioavailability, in vitro, Na2EDTA, wheat flour, zincABSTRAKTujuan penelitian ini adalah menganalisis perubahan ketersediaan biologis seng (Zn yang terjadi akibat penambahan Na2EDTA dan pengolahan terigu yang difortifikasi. Uji ketersediaan biologis seng dilakukan secara in vitro dengan mensimulasikan pencernaan manusia. Hasil uji menunjukkan bahwa tidak terdapat perbedaan ketersediaan biologis seng yang nyata pada terigu yang digoreng (donat, dikukus (bakpau, ataupun dipanggang (roti (p>0.05. Namun, terdapat kecenderungan peningkatan ketersediaan biologis pada terigu yang diolah dengan cara digoreng (donat dan dipanggang (roti dibandingkan dengan adonan mentah. Adonan mentah memiliki nilai ketersediaan biologis seng sebesar 13.29%, setelah digoreng (donat memiliki nilai ketersediaan biologis seng sebesar 14.72% dan setelah dipanggang (roti memiliki nilai ketersediaan biologis seng sebesar 17.06%. Penambahan Na2EDTA juga tidak memberikan peningkatan ketersediaan biologis seng yang nyata pada ketiga jenis pengolahan yang

  17. Inkjet printing of silver citrate conductive ink on PET substrate

    Energy Technology Data Exchange (ETDEWEB)

    Nie Xiaolei [Key Laboratory for Green Chemical Technology of Ministry of Education, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072 (China); Wang Hong, E-mail: hongwang@tju.edu.cn [Key Laboratory for Green Chemical Technology of Ministry of Education, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072 (China); Zou Jing [Key Laboratory for Green Chemical Technology of Ministry of Education, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072 (China)

    2012-11-15

    Highlights: Black-Right-Pointing-Pointer A direct synthesis method of silver conductive film on PET substrate was presented. Black-Right-Pointing-Pointer A stable particle-free conductive ink was prepared. Black-Right-Pointing-Pointer Formation of silver-amine complex reduced the thermal decomposition temperature. Black-Right-Pointing-Pointer Conductive patterns for flexible electronics were fabricated by inkjet printing. Black-Right-Pointing-Pointer Silver film on PET substrate possessed highest adhesion rating even without polymer. - Abstract: Direct synthesis of silver conductive film on PET substrate by inkjet printing silver citrate conductive ink was presented in this paper. This kind of conductive ink contained silver citrate as silver precursor, 1,2-diaminopropane as complex agent dissolving the silver salt and methanol and isopropanol as a media adjusting the viscosity and surface tension. The formation of silver-amine complex reduced the decomposition temperature from 180 Degree-Sign C to 135 Degree-Sign C, thus the ink could be cured at relatively low temperature. The film reached the lowest resistivity of 17 {mu}{Omega} cm after cured at 150 Degree-Sign C for 50 min, 3.1 {mu}{Omega} cm at 230 Degree-Sign C and possessed high reflection and excellent adhesive property. Electrical conductivity, surface morphology and composition were investigated by four-point probe method, scanning electron microscope (SEM) and energy dispersive X-ray spectroscopy (EDS). It is demonstrated how the cured condition affects the silver film. Moreover, radio-frequency identification (RFID) antenna was fabricated by inkjet printing, which opens up routes for the flexible electronics fabrication.

  18. Internet-ordered viagra (sildenafil citrate) is rarely genuine.

    Science.gov (United States)

    Campbell, Neil; Clark, John P; Stecher, Vera J; Goldstein, Irwin

    2012-11-01

    Counterfeit medication is a growing problem. This study assessed the requirement for prescription, cost, origin, and content of medications sold via the Internet and purporting to be the phosphodiesterase type 5 inhibitor Viagra (sildenafil citrate). Pfizer monitored top search results for the query "buy Viagra" on the two leading Internet search engines in March 2011. Orders were placed from 22 unique Web sites claiming to sell Viagra manufactured by Pfizer. Tablets received were assessed for chemical composition. No Web site examined required a prescription for purchase or a health screening survey; 90% offered illegal "generic Viagra." Cost per tablet ranged from $3.28-$33.00. Shipment origins of purchases were Hong Kong (N = 11), the United States (N = 6), and the United Kingdom (N = 2) as well as Canada, China, and India (N = 1 each). Notably, the four Internet pharmacies claiming to be Canadian did not ship medication from a Canadian address. Of 22 sample tablets examined, 17 (77%) were counterfeit, 4 (18%) were authentic, and 1 (5%) was an illegal generic. Counterfeit tablets were analyzed for sildenafil citrate, the active pharmaceutical ingredient (API) of Viagra, and contents varied between 30% and 50% of the label claim. Counterfeits lacked product information leaflets, including appropriate safety warnings, and genuine Viagra formulations. Internet sites claiming to sell authentic Viagra shipped counterfeit medication 77% of the time; counterfeits usually came from non-U.S. addresses and had 30% to 50% of the labeled API claim. Caution is warranted when purchasing Viagra via the Internet. © 2012 International Society for Sexual Medicine.

  19. Inkjet printing of silver citrate conductive ink on PET substrate

    International Nuclear Information System (INIS)

    Nie Xiaolei; Wang Hong; Zou Jing

    2012-01-01

    Highlights: ► A direct synthesis method of silver conductive film on PET substrate was presented. ► A stable particle-free conductive ink was prepared. ► Formation of silver-amine complex reduced the thermal decomposition temperature. ► Conductive patterns for flexible electronics were fabricated by inkjet printing. ► Silver film on PET substrate possessed highest adhesion rating even without polymer. - Abstract: Direct synthesis of silver conductive film on PET substrate by inkjet printing silver citrate conductive ink was presented in this paper. This kind of conductive ink contained silver citrate as silver precursor, 1,2-diaminopropane as complex agent dissolving the silver salt and methanol and isopropanol as a media adjusting the viscosity and surface tension. The formation of silver-amine complex reduced the decomposition temperature from 180 °C to 135 °C, thus the ink could be cured at relatively low temperature. The film reached the lowest resistivity of 17 μΩ cm after cured at 150 °C for 50 min, 3.1 μΩ cm at 230 °C and possessed high reflection and excellent adhesive property. Electrical conductivity, surface morphology and composition were investigated by four-point probe method, scanning electron microscope (SEM) and energy dispersive X-ray spectroscopy (EDS). It is demonstrated how the cured condition affects the silver film. Moreover, radio-frequency identification (RFID) antenna was fabricated by inkjet printing, which opens up routes for the flexible electronics fabrication.

  20. Reactivity of OH· and e-aq from electron beam irradiation of aqueous solutions of EDTA and aminopolycarboxylic acids

    International Nuclear Information System (INIS)

    Vel Leitner, N.K.; Guilbault, I.; Legube, B.

    2003-01-01

    Electron beam irradiation of aqueous solutions of EDTA, EDDA NN', NTA, IDA and Cu-EDTA was performed in the presence of scavengers for the hydroxyl radicals (methanol) or for the solvated electrons (hydrogen peroxide). Experiments showed that for each molecule, the G-value decreases as the radiation dose increases from 1 to 25 kGy, and for EDTA, when the initial concentration decreases from 10 to 0.1 mmol l -1 . At pH 8 and for 5 kGy, the G-values of NTA, IDA, EDTA and EDDA NN' removal ascribed to OH · radicals are, respectively, 0.06, 0.06, 0.15 and 0.20 μmol J -1 , whereas for the solvated electrons the G-values were, respectively, 0.01, 0.01, 0.06 and 0.04 μmol J -1 . The rate constants of hydroxyl radicals and solvated electrons were determined by comparison with one competitor. For each active species (hydroxyl radical or solvated electron), the reactivity is connected to the number of nitrogen atoms and acetate groups. The rate constants of OH · radicals are above 10 10 and 8.6x10 9 l mol -1 s -1 for EDDA NN' and EDTA, respectively, 2.1x10 9 l mol -1 s -1 for IDA and 6.1x10 8 l mol -1 s -1 for NTA. The reactivity of solvated electrons is smaller and the rate constants are in the range 1.9x10 6 -3.7x10 6 l mol -1 s -1 for NTA, IDA and EDDA NN' and equal 1.4x10 7 l mol -1 s -1 for EDTA. The reactivity of the complex Cu-EDTA towards OH · does not differ to a large extent from EDTA whereas with e - aq the reactivity of Cu-EDTA is better than EDTA since k e - /Cu-EDTA reaches 2.2x10 9 l mol -1 s -1 . It follows that when both active entities (OH · and e - aq ) are involved in the electron beam irradiation process, the removal of free aminopolycarboxylic acids is mainly due to OH · radicals. However, the complex Cu-EDTA is concerned by both e - aq and OH · radicals

  1. Mobilisation of heavy metals into the urine by CaEDTA: relation to erythrocyte and plasma concentrations and exposure indicators.

    OpenAIRE

    Araki, S; Aono, H; Murata, K

    1986-01-01

    To investigate the effects of calcium disodium ethylenediamine tetra-acetate (CaEDTA) on the urinary excretion, erythrocyte, and plasma concentrations and exposure indicators of seven heavy metals, CaEDTA was administered by intravenous infusion to 20 workers exposed to lead, zinc, and copper. The workers' blood lead concentrations ranged from 22 to 59 micrograms/dl (mean 38 micrograms/dl (1.8 mumol/l]. The 24 hour urinary excretion of metals after CaEDTA administration (mobilisation yield) w...

  2. The optimal period of Ca-EDTA treatment for parthenogenetic activation of porcine oocytes during maturation culture

    OpenAIRE

    MORITA, Yasuhiro; TANIGUCHI, Masayasu; TANIHARA, Fuminori; ITO, Aya; NAMULA, Zhao; DO, Lanh Thi Kim; TAKAGI, Mitsuhiro; TAKEMOTO, Tatsuya; OTOI, Takeshige

    2016-01-01

    The changes triggered by sperm-induced activation of oocytes, which are required for normal oocyte development, can be mediated by other agents, thereby inducing the parthenogenesis. In this study, we exposed porcine oocytes to 1 mM Ca-EDTA, a metal-ion chelator, at various intervals during 48 hr of in vitro maturation to determine the optimum period of Ca-EDTA treatment for parthenogenetic activation. When the oocytes were cultured with or without Ca-EDTA from 36 hr (post-12), 24 hr (post-24...

  3. Static mechanical properties of buffer material

    International Nuclear Information System (INIS)

    Takaji, Kazuhiko; Suzuki, Hideaki

    1999-11-01

    The buffer material is expected to maintain its low water permeability, self-sealing properties, radionuclides adsorption and retardation properties, thermal conductivity, chemical buffering properties, overpack supporting properties, stress buffering properties, etc. over a long period of time. Natural clay is mentioned as a material that can relatively satisfy above. Among the kinds of natural clay, bentonite when compacted is superior because (i) it has exceptionally low water permeability and properties to control the movement of water in buffer, (ii) it fills void spaces in the buffer and fractures in the host rock as it swells upon water uptake, (iii) it has the ability to exchange cations and to adsorb cationic radioelements. In order to confirm these functions for the purpose of safety assessment, it is necessary to evaluate buffer properties through laboratory tests and engineering-scale tests, and to make assessments based on the ranges in the data obtained. This report describes the procedures, test conditions, results and examinations on the buffer material of unconfined compression tests, one-dimensional consolidation tests, consolidated-undrained triaxial compression tests and consolidated-undrained triaxial creep tests that aim at getting hold of static mechanical properties. We can get hold of the relationship between the dry density and tensile stress etc. by Brazilian tests, between the dry density and unconfined compressive strength etc. by unconfined compression tests, between the consolidation stress and void ratio etc. by one-dimensional consolidation tests, the stress pass of each effective confining pressure etc. by consolidated-undrained triaxial compression tests and the axial strain rate with time of each axial stress etc. by consolidated-undrained triaxial creep tests. (author)

  4. Temperature Buffer Test. Measurements of water content and density of the excavated buffer material

    Energy Technology Data Exchange (ETDEWEB)

    Johannesson, Lars-Erik [Clay Technology AB, Lund (Sweden)

    2010-12-15

    TBT (Temperature Buffer Test) is a joint project between SKB/ANDRA and supported by ENRESA (modeling) and DBE (instrumentation), which aims at understanding and modeling the thermo-hydromechanical behavior of buffers made of swelling clay submitted to high temperatures (over 100 deg C) during the water saturation process. The test was carried out at the - 420 m level in Aespoe HRL in a 8 meters deep and 1.76 m diameter deposition hole, with two heaters (3 m long, 0.6 m diameter), surrounded by a MX-80 bentonite buffer and a confining plug on top anchored with 9 rods. It was installed during spring 2003. The bentonite around upper heater was removed during the period October - December 2009 and the buffer around the lower heater was removed during January - Mars 2010. During dismantling of the buffer, samples were taken on which analyses were made. This report describes the work with the deteroemoeination of the water content and the density of the taken samples. Most of the samples were taken from the buffer by core drilling from the upper surface of each installed bentonite block. The cores had a diameter of about 50 mm and a maximum length equal to the original height of the bentonite blocks (about 500 mm). The water content of the buffer was determined by drying a sample at a temperature of 105 deg C for 24 h and the bulk density was determined by weighing a sample both in the air and immerged in paraffin oil with known density. The water content, dry density, degree of saturation and void ratio of the buffer were then plotted. The plots show that all parts of the buffer had taken up water and the degree of saturation of the buffer varied between 90 - 100%. Large variation in the dry density of the buffer was also observed.

  5. Post-Dilution on Line Haemodiafiltration with Citrate Dialysate: First Clinical Experience in Chronic Dialysis Patients

    Directory of Open Access Journals (Sweden)

    Vincenzo Panichi

    2013-01-01

    Full Text Available Background. Citrate has anticoagulative properties and favorable effects on inflammation, but it has the potential hazards of inducing hypocalcemia. Bicarbonate dialysate (BHD replacing citrate for acetate is now used in chronic haemodialysis but has never been tested in postdilution online haemodiafiltration (OL-HDF. Methods. Thirteen chronic stable dialysis patients were enrolled in a pilot, short-term study. Patients underwent one week (3 dialysis sessions of BHD with 0.8 mmol/L citrate dialysate, followed by one week of postdilution high volume OL-HDF with standard bicarbonate dialysate, and one week of high volume OL-HDF with 0.8 mmol/L citrate dialysate. Results. In citrate OL-HDF pretreatment plasma levels of C-reactive protein and β2-microglobulin were significantly reduced; intra-treatment plasma acetate levels increased in the former technique and decreased in the latter. During both citrate techniques (OL-HDF and HD ionized calcium levels remained stable within the normal range. Conclusions. Should our promising results be confirmed in a long-term study on a wider population, then OL-HDF with citrate dialysate may represent a further step in improving dialysis biocompatibility.

  6. Combined oral administration of bovine collagen peptides with calcium citrate inhibits bone loss in ovariectomized rats.

    Science.gov (United States)

    Liu, JunLi; Wang, YiHu; Song, ShuJun; Wang, XiJie; Qin, YaYa; Si, ShaoYan; Guo, YanChuan

    2015-01-01

    Collagen peptides (CPs) and calcium citrate are commonly used as bone health supplements for treating osteoporosis. However, it remains unknown whether the combination of oral bovine CPs with calcium citrate is more effective than administration of either agent alone. Forty 12-week-old Sprague-Dawley rats were randomly divided into five groups (n = 8) for once-daily intragastric administration of different treatments for 3 months at 3 months after ovariectomy (OVX) as follows: sham + vehicle; OVX + vehicle; OVX + 750 mg/kg CP; OVX + CP-calcium citrate (75 mg/kg); OVX + calcium citrate (75 mg/kg). After euthanasia, the femurs were removed and analyzed by dual energy X-ray absorptiometry and micro-computed tomography, and serum samples were analyzed for bone metabolic markers. OVX rats supplemented with CPs or CP-calcium citrate showed osteoprotective effects, with reductions in the OVX-induced decreases in their femoral bone mineral density. Moreover, CP-calcium citrate prevented trabecular bone loss, improved the microarchitecture of the distal femur, and significantly inhibited bone loss with increased bone volume, connectivity density, and trabecular number compared with OVX control rats. CP or CP-calcium citrate administration significantly increased serum procollagen type I N-terminal propeptide levels and reduced serum bone-specific alkaline phosphatase, osteocalcin, and C-telopeptide of type I collagen levels. Our data indicate that combined oral administration of bovine CPs with calcium citrate inhibits bone loss in OVX rats. The present findings suggest that combined oral administration of bovine CPs with calcium citrate is a promising alternative for reducing bone loss in osteopenic postmenopausal women.

  7. Affinity for a malignant tumor and organs of sup(99m)Tc-citrate complex

    Energy Technology Data Exchange (ETDEWEB)

    Ando, A; Sanada, S; Hiraki, T [Kanazawa Univ. (Japan). School of Paramedicine; Hisada, K; Nakazawa, N

    1976-12-01

    In order to investigate the tumor affinity of sup(99m)Tc-citrate complex, it was synthesized in three different ways. By (1) reducing sup(99m)TcO/sub 4//sup -/ with FeCl/sub 3//sup -/ ascorbic acid in 0.15 M sodium citrate, (2) reducing sup(99m)TcO/sub 4//sup -/ with SnCl/sub 2/ solution in 0.15 M sodium citrate, and (3) reducing sup(99m)TcO/sub 4//sup -/ with NaBH/sub 4/ in 0.45 sodium citrate. It was presumed from thinlayer chromatography that the sup(99m)Tc-citrate complexes synthesized in three ways were chemically different. These sup(99m)Tc-citrate complexes were injected intravenously into the rats subcutaneously transplanted with Yoshida sarcoma. These rats were sacrificed at one hour and three hours after injection. The radioactivity of the tumor, blood, muscle, liver, kidney, spleen and urine was measured by well-type scintillation counter. The retention values in these organs and the excretion rates in the urine were calculated. sup(99m)Tc-citrate complex synthesized by reducing sup(99m)TcO/sub 4//sup -/ with SnCl/sub 2/ solution had very strong affinity for the malignant tumor but the other two sup(99m)Tc-citrate complexes had no affinity to the malignant tumor. Excretion rates (% dose) of sup(99m)Tc-citrate complexes in one hour were from 65% to 75%.

  8. Combined oral administration of bovine collagen peptides with calcium citrate inhibits bone loss in ovariectomized rats.

    Directory of Open Access Journals (Sweden)

    JunLi Liu

    Full Text Available Collagen peptides (CPs and calcium citrate are commonly used as bone health supplements for treating osteoporosis. However, it remains unknown whether the combination of oral bovine CPs with calcium citrate is more effective than administration of either agent alone.Forty 12-week-old Sprague-Dawley rats were randomly divided into five groups (n = 8 for once-daily intragastric administration of different treatments for 3 months at 3 months after ovariectomy (OVX as follows: sham + vehicle; OVX + vehicle; OVX + 750 mg/kg CP; OVX + CP-calcium citrate (75 mg/kg; OVX + calcium citrate (75 mg/kg. After euthanasia, the femurs were removed and analyzed by dual energy X-ray absorptiometry and micro-computed tomography, and serum samples were analyzed for bone metabolic markers.OVX rats supplemented with CPs or CP-calcium citrate showed osteoprotective effects, with reductions in the OVX-induced decreases in their femoral bone mineral density. Moreover, CP-calcium citrate prevented trabecular bone loss, improved the microarchitecture of the distal femur, and significantly inhibited bone loss with increased bone volume, connectivity density, and trabecular number compared with OVX control rats. CP or CP-calcium citrate administration significantly increased serum procollagen type I N-terminal propeptide levels and reduced serum bone-specific alkaline phosphatase, osteocalcin, and C-telopeptide of type I collagen levels.Our data indicate that combined oral administration of bovine CPs with calcium citrate inhibits bone loss in OVX rats. The present findings suggest that combined oral administration of bovine CPs with calcium citrate is a promising alternative for reducing bone loss in osteopenic postmenopausal women.

  9. Alkali replacement raises urinary citrate excretion in patients with topiramate-induced hypocitraturia.

    Science.gov (United States)

    Jhagroo, R Allan; Wertheim, Margaret L; Penniston, Kristina L

    2016-01-01

    The aims of this study were to assess (1) the magnitude and temporality of decreased urinary citrate excretion in patients just starting topiramate and (2) the effect of alkali replacement on topiramate-induced hypocitraturia. Study 1 was a prospective, non-intervention study in which patients starting topiramate for headache remediation provided pre- and post-topiramate 24 h urine collections for measurement of urine citrate. Study 2 was a clinical comparative effectiveness study in which patients reporting to our stone clinic for kidney stones and who were treated with topiramate were prescribed alkali therapy. Pre- and post-alkali 24 h urinary citrate excretion was compared. Data for 12 and 22 patients (studies 1 and 2 respectively) were evaluated. After starting topiramate, urinary citrate excretion dropped significantly by 30 days (P = 0.016) and 62% of patients had hypocitraturia (citrate alkali, urine citrate increased in stone-forming patients on topiramate (198 ± 120 to 408 ± 274 mg day(-1) ; P = 0.042 for difference). 85% of patients were hypocitraturic on topiramate alone vs. 40% after adding alkali. The increase in urinary citrate was greater in patients provided ≥ 90 mEq potassium citrate. Our study is the first to provide clinical evidence that alkali therapy can raise urinary citrate excretion in patients who form kidney stones while being treated with topiramate. Clinicians should consider alkali therapy for reducing the kidney stone risk of patients benefitting from topiramate treatment for migraine headaches or other conditions. © 2015 The British Pharmacological Society.

  10. Scientific Applications Performance Evaluation on Burst Buffer

    KAUST Repository

    Markomanolis, George S.

    2017-10-19

    Parallel I/O is an integral component of modern high performance computing, especially in storing and processing very large datasets, such as the case of seismic imaging, CFD, combustion and weather modeling. The storage hierarchy includes nowadays additional layers, the latest being the usage of SSD-based storage as a Burst Buffer for I/O acceleration. We present an in-depth analysis on how to use Burst Buffer for specific cases and how the internal MPI I/O aggregators operate according to the options that the user provides during his job submission. We analyze the performance of a range of I/O intensive scientific applications, at various scales on a large installation of Lustre parallel file system compared to an SSD-based Burst Buffer. Our results show a performance improvement over Lustre when using Burst Buffer. Moreover, we show results from a data hierarchy library which indicate that the standard I/O approaches are not enough to get the expected performance from this technology. The performance gain on the total execution time of the studied applications is between 1.16 and 3 times compared to Lustre. One of the test cases achieved an impressive I/O throughput of 900 GB/s on Burst Buffer.

  11. Effect of EDTA and gypsum on self diffusion coefficient of zinc in alkali soil

    International Nuclear Information System (INIS)

    Gupta, G.N.; Deb, D.L.

    1981-01-01

    The effect of EDTA and gypsum application on the rate of zinc diffusion was studied in an alkali soil. Gypsum application at the rate of half gypsum requirement (GR) increased the apparent self diffusion coefficient of zinc (DaZn) and decreased the capacity factor (B) of soil. The higher rates (full GR and double GR) depressed the rate of zinc diffusion and increased the B value. Application of EDTA at the rate of 0.77 μeg -1 of soil produced 1600 and 24 fold increase in DaZn and DpZn values respectively and 100 times drop in B value. Addition of 55 ppm Zn to the soil significantly increased the DaZn and DpZn values. (author)

  12. Intestinal permeability to [51Cr]EDTA in children with cystic fibrosis

    International Nuclear Information System (INIS)

    Leclercq-Foucart, J.; Forget, P.; Sodoyez-Goffaux, F.; Zappitelli, A.

    1986-01-01

    Intestinal permeability was investigated in 14 children with cystic fibrosis making use of [ 51 Cr]EDTA as probe molecule. Ten normal young adults and 11 children served as controls. After oral administration of [ 51 Cr]EDTA, 24 h urine was collected. Urinary radioactivity was calculated and results expressed as percentage of oral dose excreted in 24 h urine. Mean and SEM were as follows: 2.51 +/- 0.21, 2.35 +/- 0.24, and 13.19 +/- 1.72 for control children, normal adults, and cystic fibrosis patients, respectively. The permeability differences between cystic fibrosis patients and either control children or control adults are significant (p less than 0.001)

  13. A novel biamperometric methodology for thorium determination by EDTA complexometric titration

    International Nuclear Information System (INIS)

    Jayachandran, K.; Gamare, J.S.; Nair, P.R.; Xavier, M.; Aggarwal, S.K.

    2012-01-01

    A biamperometric methodology is described for the determination of thorium by EDTA complexometric titration, based on the observed electrochemical behaviour of EDTA when the applied potential was ≥ 200 mV between the twin Pt electrodes. Studies carried out showed that a pH range of 2.4-2.7 was optimum for the determination. Accuracy and precision of the method were evaluated using different amounts of thorium ranging from 50 μg to 5 mg. Studies on the interference of uranium were carried out with different amounts of uranium ranging from 20 to 80% using the presently developed approach of biamperometry as well as the conventional indicator method. The method was employed for the determination of Th in (Th,U)O 2 samples containing different amounts of Th and U. (orig.)

  14. Adsorption of manganese(II) ions by EDTA-treated activated carbons

    Energy Technology Data Exchange (ETDEWEB)

    Khan, A.Y.; Mazyck, D.W. [Jones Edmunds & Associates, Gainesville, FL (United States)

    2009-07-01

    The adsorption of manganese(II) ions from aqueous solution onto three different granular activated carbons treated with ethylenediamine tetraacetic acid (EDTA) and its sodium salt was investigated. Characterization of the chelate-treated carbons showed that EDTA altered the physical and chemical properties of the sorbents relative to their untreated counterparts. Furthermore, the modified sorbents exhibited a heightened capacity towards the adsorption of Mn(II) ions from aqueous media. Manganese(II) ion removal increased from 0 to 6.5 mg/g for the lignite coal-based sorbent, from 3.5 to 14.7 mg/g for the wood-based sorbent and from 1.3 to 7.9 mg/g for the bituminous coal-based sorbent. The increased removal is attributed, in part, to the creation of Lewis base sites that participate in covalent interactions and hydrolysis reactions.

  15. Structural modification of mordenite zeolite with Fe For the photo-degradation of EDTA

    International Nuclear Information System (INIS)

    Emara, Mostafa M.; Tourky, Amal S.M.; El-Moselhy, Medhat M.

    2009-01-01

    Fe 2+ was incorporated inside mordenite through ion exchange technique in aqueous solution. The amount of Fe loading was 25-100 wt %, using FeSO 4 .7H 2 O as precursor and Na-mordenite starting material Na-M. The Fe incorporated (Fe-M) thus prepared was characterized by XRD, FTIR and N 2 adsorption measurements. It was found that Fe mordenite retained the same structure as that for Na-mordenite which may indicate that Fe well dispersed into mordenite channels. BET indicated that Fe-M samples possessed higher surface area compared to the parent Na-M. Photocatalytic degradation of EDTA was carried out in presence of the prepared Fe-M catalysts. Effects of catalyst concentration and temperature were also studied. Thermodynamic parameters calculated for 50% Fe-M showed the highest catalytic activity toward EDTA degradation.

  16. Structural modification of mordenite zeolite with Fe For the photo-degradation of EDTA

    Energy Technology Data Exchange (ETDEWEB)

    Emara, Mostafa M. [Chemistry Department, Faculty of Science (boys), Al-Azha University, Nasr city 11884, Cairo (Egypt); Tourky, Amal S.M. [Chemistry Department, Faculty of Science (Girls), Al-Azhar University, Nasr city, Cairo (Egypt); El-Moselhy, Medhat M., E-mail: medhatmohamed@yahoo.com [Chemistry Department, Faculty of Science (boys), Al-Azha University, Nasr city 11884, Cairo (Egypt)

    2009-07-15

    Fe{sup 2+} was incorporated inside mordenite through ion exchange technique in aqueous solution. The amount of Fe loading was 25-100 wt %, using FeSO{sub 4}.7H{sub 2}O as precursor and Na-mordenite starting material Na-M. The Fe incorporated (Fe-M) thus prepared was characterized by XRD, FTIR and N{sub 2} adsorption measurements. It was found that Fe mordenite retained the same structure as that for Na-mordenite which may indicate that Fe well dispersed into mordenite channels. BET indicated that Fe-M samples possessed higher surface area compared to the parent Na-M. Photocatalytic degradation of EDTA was carried out in presence of the prepared Fe-M catalysts. Effects of catalyst concentration and temperature were also studied. Thermodynamic parameters calculated for 50% Fe-M showed the highest catalytic activity toward EDTA degradation.

  17. Thermometric titration of thorium with EDTA in the presence of large excess of neutral sodium salts.

    Science.gov (United States)

    Doi, K

    1980-11-01

    The thermometric titration of Th(IV) in the presence of neutral sodium salts, sulphuric acid or acetic acid with EDTA has been studied. The effect of each on the observed heat values for the titration is discussed. For sodium perchlorate media, DeltaH values of -9 and -21 kJ/mole have been estimated for the formation of the Th(IV)-EDTA chelate at mu --> 0 and mu = 0.5 (NaClO(4)), respectively. The -DeltaH values increase steadily with increase in concentration of sodium perchlorate up to at least 3M. For the titration of Th(IV) in the presence of a large excess of sodium nitrate the use of sodium iodide as a masking reagent has been examined: large amounts of Bi and Cu(II) are masked and a masking effect is observed for small amounts of Ni.

  18. 99mTc-EDTA and 99mTc-DTPA complexes as hydrological tracers

    International Nuclear Information System (INIS)

    Dominguez, J.; Borroto, J.; Nazco, J.; Perez, E.; Gamboa, R.; Cruz, J.

    2002-01-01

    The [ 99m Tc-DTPA] 2- and [ 99m Tc-EDTA] 1- were evaluated as radiotracers for short time hydrological studies. Their complex stability after labelling with 9.25 GBq of 99m Tc, the behaviour against pH variations, from 5 to 9, in simulated solutions and in natural river waters and the sorption of these compounds on the river sediments, were tested in laboratory experiments. Finally field double tracing experiments were carried out for each of labelling complexes and Rhodamine WT. From recovery calculations not losses of the 99m Tc activity were observed. The shape of the RTD curves of the [ 99m Tc-DTPA] 2- and [ 99m Tc-EDTA] 1 were quite similar to the Rhodamine Wt ones. May be concluded that both complexes behaved conservatively on the studied environmental conditions. (author)

  19. Chromium 51 EDTA/technetium 99m MDP plasma ratio to measure total skeletal function

    Energy Technology Data Exchange (ETDEWEB)

    Nisbet, A.P.; Edwards, S.; Lazarus, C.R.; Malamitsi, J.; Maisey, M.N.; Mashiter, G.D.; Winn, P.J. (Guy' s Hospital, London (UK))

    1984-08-01

    A method is described for the quantitation of total skeletal activity during bone scans. The method requires a single plasma sample only, taken at the time of imaging. The ratio of % injected dose of /sup 51/Cr EDTA to that of /sup 99/Tcsup(m) MDP is calculated from this sample following combined injection of the two radiopharmaceuticals. The /sup 51/Cr EDTA level corrects for the glomerular filtration of /sup 99/Tcsup(m) MDP. Using this method, which only requires a gamma counter, significant differences from normal controls have been shown in patients with osteomalacia, renal osteodystrophy, Paget's disease and hypercalcaemia. The method provides routine quantitative data to add to the imaging information in the bone scan.

  20. A study of 153Sm-citrate-hydroxyapatite synovectomy in knee synovitis with rheumatoid arthritis

    International Nuclear Information System (INIS)

    Fan Yanggang; Li Guohua; Yao Guozhong; Zhang Qingcheng; Li Guangming

    2006-01-01

    Objective: To investigate the efficacy and safety of 153 Sm-citrate-hydroxyapatite (HA) synovectomy in knee synovitis with rheumatoid arthritis (RA). Methods: In 43 RA patients ineffective to routine anti-rheumatic drugs (DMMARDs) therapy, radiation synovectomy was performed by 153 Sm-citrate-HA in 67 joints and its efficacy and safety were evaluated. Results: Radioactivity was evenly distributed as observed by gamma camera after injection. In 8 cases leakage of radioactivity was detected after 24 h, and accounted to 153 Sm-citrate-HA synovectomy is effective after short-term and medium-term follow-up and it is a safe procedure. (authors)

  1. A Process-Based Model of TCA Cycle Functioning to Analyze Citrate Accumulation in Pre- and Post-Harvest Fruits.

    Science.gov (United States)

    Etienne, Audrey; Génard, Michel; Bugaud, Christophe

    2015-01-01

    Citrate is one of the most important organic acids in many fruits and its concentration plays a critical role in organoleptic properties. The regulation of citrate accumulation throughout fruit development, and the origins of the phenotypic variability of the citrate concentration within fruit species remain to be clarified. In the present study, we developed a process-based model of citrate accumulation based on a simplified representation of the TCA cycle to predict citrate concentration in fruit pulp during the pre- and post-harvest stages. Banana fruit was taken as a reference because it has the particularity of having post-harvest ripening, during which citrate concentration undergoes substantial changes. The model was calibrated and validated on the two stages, using data sets from three contrasting cultivars in terms of citrate accumulation, and incorporated different fruit load, potassium supply, and harvest dates. The model predicted the pre and post-harvest dynamics of citrate concentration with fairly good accuracy for the three cultivars. The model suggested major differences in TCA cycle functioning among cultivars during post-harvest ripening of banana, and pointed to a potential role for NAD-malic enzyme and mitochondrial malate carriers in the genotypic variability of citrate concentration. The sensitivity of citrate accumulation to growth parameters and temperature differed among cultivars during post-harvest ripening. Finally, the model can be used as a conceptual basis to study citrate accumulation in fleshy fruits and may be a powerful tool to improve our understanding of fruit acidity.

  2. A Process-Based Model of TCA Cycle Functioning to Analyze Citrate Accumulation in Pre- and Post-Harvest Fruits.

    Directory of Open Access Journals (Sweden)

    Audrey Etienne

    Full Text Available Citrate is one of the most important organic acids in many fruits and its concentration plays a critical role in organoleptic properties. The regulation of citrate accumulation throughout fruit development, and the origins of the phenotypic variability of the citrate concentration within fruit species remain to be clarified. In the present study, we developed a process-based model of citrate accumulation based on a simplified representation of the TCA cycle to predict citrate concentration in fruit pulp during the pre- and post-harvest stages. Banana fruit was taken as a reference because it has the particularity of having post-harvest ripening, during which citrate concentration undergoes substantial changes. The model was calibrated and validated on the two stages, using data sets from three contrasting cultivars in terms of citrate accumulation, and incorporated different fruit load, potassium supply, and harvest dates. The model predicted the pre and post-harvest dynamics of citrate concentration with fairly good accuracy for the three cultivars. The model suggested major differences in TCA cycle functioning among cultivars during post-harvest ripening of banana, and pointed to a potential role for NAD-malic enzyme and mitochondrial malate carriers in the genotypic variability of citrate concentration. The sensitivity of citrate accumulation to growth parameters and temperature differed among cultivars during post-harvest ripening. Finally, the model can be used as a conceptual basis to study citrate accumulation in fleshy fruits and may be a powerful tool to improve our understanding of fruit acidity.

  3. Improved indexes for targeting placement of buffers of Hortonian runoff

    Science.gov (United States)

    M.G. Dosskey; Z. Qiu; M.J. Helmers; D.E. Eisenhauer

    2011-01-01

    Targeting specific locations within agricultural watersheds for installing vegetative buffers has been advocated as a way to enhance the impact of buffers and buffer programs on stream water quality. Existing models for targeting buffers of Hortonian, or infiltration-excess, runoff are not well developed. The objective was to improve on an existing soil survey–based...

  4. A buffer overflow detection based on inequalities solution

    International Nuclear Information System (INIS)

    Xu Guoai; Zhang Miao; Yang Yixian

    2007-01-01

    A new buffer overflow detection model based on Inequalities Solution was designed, which is based on analyzing disadvantage of the old buffer overflow detection technique and successfully converting buffer overflow detection to Inequalities Solution. The new model can conquer the disadvantage of the old technique and improve efficiency of buffer overflow detection. (authors)

  5. Treatment of Ni-EDTA containing wastewater by electrocoagulation using iron scraps packed-bed anode.

    Science.gov (United States)

    Ye, Xiaokun; Zhang, Junya; Zhang, Yan; Lv, Yuancai; Dou, Rongni; Wen, Shulong; Li, Lianghao; Chen, Yuancai; Hu, YongYou

    2016-12-01

    The unique electrocoagulator proposed in this study is highly efficient at removing Ni-EDTA, providing a potential remediation option for wastewater containing lower concentrations of Ni-EDTA (Ni ≤ 10 mg L -1 ). In the electrocoagulation (EC) system, cylindrical graphite was used as a cathode, and a packed-bed formed from iron scraps was used as an anode. The results showed that the removal of Ni-EDTA increased with the application of current and favoured acidic conditions. We also found that the iron scrap packed-bed anode was superior in its treatment ability and specific energy consumption (SECS) compared with the iron rod anode. In addition, the packed density and temperature had a large influence on the energy consumption (ECS). Over 94.3% of Ni and 95.8% of TOC were removed when conducting the EC treatment at an applied current of 0.5 A, initial pH of 3, air-purged rate 0.2 L min -1 , anode packed density of 400 kg m -3 temperature of 313 K and time of 30 min. SEM analysis of the iron scraps indicated that the specific area of the anode increased after the EC. The XRD analysis of flocs produced during EC revealed that hematite (α-Fe 2 O 3 ) and magnetite (Fe 3 O 4 ) were the main by-products under aerobic and anoxic conditions, respectively. A kinetic study demonstrated that the removal of Ni-EDTA followed a first-order model with the current parameters. Moreover, the removal efficiency of real wastewater was essentially consistent with that of synthetic wastewater. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Field and laboratory evaluation of the mobility of cobalt-60/EDTA in an arid environment

    International Nuclear Information System (INIS)

    Jones, T.L.; Gee, G.W.; Swanson, J.L.; Kirkham, R.R.

    1983-02-01

    The ability of the organic complexant EDTA to enhance the mobility of cobalt-60 was investigated in both laboratory and field experiments. Laboratory tests consisted of short term (approximately 7 day) column and batch adsorption tests using soil from the Hanford site as well as long term (approximately 70 day) batch tests with Hanford soil and soils from Oak Ridge and Savannah River. In addition, two large scale tracer tests were conducted using Hanford soil. One used a large (1.6 m) laboratory column, spiked with cobalt-60/EDTA and the other was a field test conducted in an 8 m deep lysimeter. Enhanced mobility decreased sorption were observed in both column and batch tests when the cobalt-60/EDTA solutions contacted Hanford and Oak Ridge soil for only a few days. When long contact times were allowed (months) the Hanford soil showed large increases in sorption with time. The low sorption exhibited initially by the Oak Ridge soil increased slightly over time, however, the high sorption observed with the Savannah River soil remained constant with time. The reduced mobility, with time, observed in Hanford soils was confirmed in both the large scale laboratory and breaking down when contacted with Hanford and Savannah River soil and to a lesser extent, the Oak Ridge soil. It is not known at this time why the complex is breaking down or why the kinetics are different among the soils tested. The implication to waste management is that the potential for transport of cobalt by EDTA complexation may not be as serious as once thought

  7. Design of Ion-Exchange Resins Through EDTA and DTPA Modified Ligands

    Directory of Open Access Journals (Sweden)

    2014-07-01

    Catechol, resorcinol, and their admixtures with EDTA and DTPA moieties were converted into polymeric resins by alkaline polycondensation with formaldehyde. The resins were characterized by FTIR spectroscopy, elemental analysis, ion-exchange capacity, and distribution coefficient (D for heavy metal and radionuclide such as Cs and Sr. 137Cs and 90Sr constitutes a major source of heat in nuclear waste streams and in regards to recent nuclear event their remediation in complex solution – sea water - represent an important issue.

  8. Silver-zinc electrodeposition from a thiourea solution with added EDTA or HEDTA

    International Nuclear Information System (INIS)

    Oliveira, G.M. de; Carlos, I.A.

    2009-01-01

    This paper shows the study of silver-zinc electrodeposition from a thiourea solution with added (ethylenedinitrilo)tetraacetic acid (EDTA), disodium salt and N-(2-hydroxyethyl)ethylenediaminetriacetic acid (HEDTA), trisodium salt. Voltammetric results indicated that silver-zinc alloy can be obtained applying overpotential higher than 0.495 V, in Tu solution containing 1.0 x 10 -1 mol L -1 Zn(NO 3 ) 2 + 2.5 x 10 -2 mol L -1 AgNO 3 . This was due to silver(I) ion complexation with thiourea, which shifted the silver deposition potential to more negative value and due to silver-zinc alloy deposition, which occurred at potentials more positive than the potential to zinc deposition alone. EDTA or HEDTA did not significantly affect the silver and zinc deposition potentials, but decreased the current density for silver-zinc deposition. Scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) analyses of the silver-zinc deposits showed that the morphology and composition changed as a function of the conditions of deposition, viz, deposition potential (E d ), deposition charge density (q d ) and solution composition (silver, EDTA and HEDTA concentrations). EDS analysis of the deposits showed sulphur (S) incorporated into the silver-zinc deposit, while SEM images showed that this sulphur content seemed to improve the silver-zinc morphology, as did the presence of EDTA and HEDTA in the solution, which enhanced the sulphur incorporation into the silver-zinc deposit. X-ray diffraction (XRD) analysis of the silver-zinc deposit showed that it was amorphous, irrespective of its composition and morphology

  9. Citrate-Induced Nanocubes: A Re-Examination of the Role of Citrate as a Shape-Directing Capping Agent for Ag-Based Nanostructures.

    Science.gov (United States)

    Hajfathalian, Maryam; Gilroy, Kyle D; Hughes, Robert A; Neretina, Svetlana

    2016-07-01

    Seed-mediated syntheses utilizing facet-selective surface passivation provide the necessary chemical controls to direct noble metal nanostructure formation to a predetermined geometry. The foremost protocol for the synthesis of (111)-faceted Ag octahedra involves the reduction of metal ions onto pre-existing seeds in the presence of citrate and ascorbic acid. It is generally accepted that the capping of (111) facets with citrate dictates the shape while ascorbic acid acts solely as the reducing agent. Herein, a citrate-based synthesis is demonstrated in which the presence or absence of ascorbic acid is the shape-determining factor. Reactions are carried out in which Ag(+) ions are reduced onto substrate-immobilized Ag, Au, Pd, and Pt seeds. Syntheses lacking ascorbic acid, in which citrate acts as both the capping and the reducing agent, result in a robust nanocube growth mode able to withstand wide variations in the concentration of reactants, reaction rates, seed material, seed orientation and faceting, pH, and substrate material. If, however, ascorbic acid is included in these syntheses, then the growth mode reverts to one that advances the octahedral geometry. The implication of these results is that citrate, or one of its oxidation products, selectively caps (100) facets, but where this capability is compromised by ascorbic acid. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Plasma electrolytic oxidation of A1050 aluminium alloy in homogeneous silicate-alkaline electrolytes with edta{sup 4−} complexes of Fe, Co, Ni, Cu, La and Ba under alternating polarization conditions

    Energy Technology Data Exchange (ETDEWEB)

    Rogov, A.B., E-mail: alex-lab@bk.ru [Nikolaev Institute of Inorganic Chemistry, 3, Acad. Lavrentiev Ave., Novosibirsk, 630090 (Russian Federation); Scientific and Technical Centre “Pokrytie-A” (OOO), 15, Dzerzhinskogo Ave., Novosibirsk, 630015 (Russian Federation)

    2015-11-01

    This work is devoted to the synthesis of coatings containing a number of transition elements by plasma electrolytic oxidation (PEO) on aluminium A1050 alloy. The paper discusses PEO coatings obtained in silicate-alkaline electrolytes containing complexes of Fe, Co, Ni, Cu, La and Ba with ethylenediaminetetraacetic anion edta{sup 4−}. It is also focused on the chemical basis of the electrolyte components choice and their role in the process of PEO. Possible mechanism of coating formation process is also discussed. Alternating current mode (symmetrical sinusoidal current pulses, initial average current density - 100 mA cm{sup −2}) was used to produce the coatings. The PEO process was characterized by behaviours of the anodic and cathodic peak voltage curves. Coating surfaces and cross sections are studied by optical dark field microscopy and scanning electron microscopy, X-ray and energy dispersive analysis. - Highlights: • Alkaline homogeneous electrolyte with transition metal-edta{sup 4-} complexes. • Coatings contain Fe, Co, Ni, Cu, La, Ba elements in alumina-silica matrix. • Alternating symmetric sinusoidal current of 100 mA cm{sup −2} was applied. • Borax buffer solution and silicate passivating agent were used.

  11. Moisture buffer capacity of different insulation materials

    DEFF Research Database (Denmark)

    Peuhkuri, Ruut Hannele; Rode, Carsten; Hansen, Kurt Kielsgaard

    2004-01-01

    . In the isothermal tests the material samples were exposed to the same change in the relative humidity of the ambient air on both sides, while the samples were exposed to variations in relative humidity only on the cold side in the non-isothermal tests. The results of these rather different measurement principles...... lead to more durable constructions. In this paper, a large range of very different thermal insulation materials have been tested in specially constructed laboratory facilities to determine their moisture buffer capacity. Both isothermal and nonisothermal experimental set-ups have been used...... are discussed, and different ways are presented how to determine the moisture buffer capacity of the materials using partly standard material parameters and partly parameters determined from the actual measurements. The results so far show that the determination of moisture buffer capacity is very sensitive...

  12. Buffer construction technique using granular bentonite

    International Nuclear Information System (INIS)

    Masuda, Ryoichi; Asano, Hidekazu; Toguri, Satohito; Mori, Takuo; Shimura, Tomoyuki; Matsuda, Takeshi; Uyama, Masao; Noda, Masaru

    2007-01-01

    Buffer construction using bentonite pellets as filling material is a promising technology for enhancing the ease of repository operation. In this study, a test of such technology was conducted in a full-scale simulated disposal drift, using a filling system which utilizes a screw conveyor system. The simulated drift, which contained two dummy overpacks, was configured as a half-cross-section model with a height of 2.22 m and a length of 6.0 m. The average dry density of the buffer obtained in the test was 1.29 Mg/m 3 , with an angle of repose of 35 to 40 degrees. These test results indicate that buffer construction using a screw conveyor system for pellet emplacement in a waste disposal drift is a promising technology for repositories for high level radioactive wastes. (author)

  13. Labview virtual instruments for calcium buffer calculations.

    Science.gov (United States)

    Reitz, Frederick B; Pollack, Gerald H

    2003-01-01

    Labview VIs based upon the calculator programs of Fabiato and Fabiato (J. Physiol. Paris 75 (1979) 463) are presented. The VIs comprise the necessary computations for the accurate preparation of multiple-metal buffers, for the back-calculation of buffer composition given known free metal concentrations and stability constants used, for the determination of free concentrations from a given buffer composition, and for the determination of apparent stability constants from absolute constants. As implemented, the VIs can concurrently account for up to three divalent metals, two monovalent metals and four ligands thereof, and the modular design of the VIs facilitates further extension of their capacity. As Labview VIs are inherently graphical, these VIs may serve as useful templates for those wishing to adapt this software to other platforms.

  14. Influence of EDTA on the electrochemical removal of mercury (II) in soil from San Joaquin, Queretaro, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Robles, I.; Serrano, T.; Perez, J. J.; Bustos, E. [Centro de Investigacion y Desarrollo Tecnologico en Electroquimica, S. C., Parque Tecnologico Queretaro, Sanfandila, Pedro Escobedo, 76703 Queretaro (Mexico); Hernandez, G.; Solis, S. [UNAM, Campus Juriquilla, Centro de Geociencias, Boulevard Juriquilla 3001, 76230 Queretaro (Mexico); Garcia, R. [UNAM, Centro de Ciencias de la Atmosfera, Ciudad Universitaria, 04510 Mexico D. F. (Mexico); Pi, T., E-mail: ebustos@cideteq.mx [UNAM, Instituto de Geologia, Ciudad Universitaria, 04510 Mexico D. F. (Mexico)

    2014-07-01

    The removal of mercury from soil and Ca-bentonite was performed using electrochemical treatment adding ethylendiamine-tetra acetic acid (EDTA) as a complexing agent to improve the electrochemical removal of Hg (II) in soil from San Joaquin, Queretaro, Mexico. During the electrokinetic treatment in the presence of 0.1 M EDTA, most of Hg (II) migrates toward the anode obtaining the highest removal efficiencies close to 70% in bentonite after 9 h. Using 0.1 M HCl only 65% efficiency was attained after 13 h in the cathodic side. EDTA formed a negatively charged stable complex that migrates to the cathode by the application of the electrokinetic treatment across Hg - EDTA synthesized complex. Finally, the predominant crystallographic structures of the samples were examined using X-ray diffraction. (Author)

  15. Effects of EDTA on phytoextraction of heavy metals (Zn, Mn and Pb) from sludge-amended soil with Brassica napus.

    Science.gov (United States)

    Zaier, Hanen; Ghnaya, Tahar; Ben Rejeb, Kilani; Lakhdar, Abdelbasset; Rejeb, Salwa; Jemal, Fatima

    2010-06-01

    Sludge application is a reliable practice to ameliorate soil fertility. However, repetitive sludge addition represents a potential soil contamination source with heavy metals, which must be extracted. The aim of this study was to evaluate the capacity of Brassica napus to remove metals from soils amended with sludge, and to study the effect of EDTA on this process. Seedlings were cultivated in presence of sludge combined or not with EDTA. Results showed that sludge ameliorate significantly biomass production. This effect was accompanied with an increase in Pb, Zn and Mn shoot concentrations. EDTA application does not affect significantly plant growth. However, this chelator enhances shoot metals accumulation. It's therefore concluded that sludge has a beneficial effect on soil fertility, B. napus can be used for the decontamination of affected soils and that the EDTA addition increases the ability of B. napus to accumulate heavy metals. Published by Elsevier Ltd.

  16. Incorporation of rare-earth ions in Mg-Al layered double hydroxides: intercalation with an [Eu(EDTA)] - chelate

    Science.gov (United States)

    Li, Cang; Wang, Ge; Evans, David G.; Duan, Xue

    2004-12-01

    Reaction of an aqueous slurry of an Mg 2Al-NO 3 layered double hydroxide with a four-fold excess of Na[Eu(EDTA)] gives a material which analyses for Mg 0.68Al 0.32(OH) 2[Eu(EDTA)] 0.10(CO 3) 0.11·0.66H 2O. The interlayer spacing of the material is 13.8 Å, corresponding to a gallery height of 9.0 Å, which accords with the maximal dimensions (9-10 Å) of the anion in metal-EDTA complex salts as determined by single crystal X-ray diffraction. Geometrical considerations show that the charge density on the layered double hydroxide layers is too high to be balanced by intercalation of [Eu(EDTA)] - alone, necessitating the co-intercalation of carbonate ions which have a much higher charge density.

  17. Influence of EDTA on the electrochemical removal of mercury (II) in soil from San Joaquin, Queretaro, Mexico

    International Nuclear Information System (INIS)

    Robles, I.; Serrano, T.; Perez, J. J.; Bustos, E.; Hernandez, G.; Solis, S.; Garcia, R.; Pi, T.

    2014-01-01

    The removal of mercury from soil and Ca-bentonite was performed using electrochemical treatment adding ethylendiamine-tetra acetic acid (EDTA) as a complexing agent to improve the electrochemical removal of Hg (II) in soil from San Joaquin, Queretaro, Mexico. During the electrokinetic treatment in the presence of 0.1 M EDTA, most of Hg (II) migrates toward the anode obtaining the highest removal efficiencies close to 70% in bentonite after 9 h. Using 0.1 M HCl only 65% efficiency was attained after 13 h in the cathodic side. EDTA formed a negatively charged stable complex that migrates to the cathode by the application of the electrokinetic treatment across Hg - EDTA synthesized complex. Finally, the predominant crystallographic structures of the samples were examined using X-ray diffraction. (Author)

  18. Influence of irradiation and Caf EDTA on the metabolism of nucleus acid of the different radiosensitive crops

    International Nuclear Information System (INIS)

    Song Daojun

    1997-01-01

    Irradiation and damage repair inhibitor (Caf and EDTA) post-treatment had a substantial effect on DNA and RNA content and DNA self-repairing synthesis. The experiment results showed the content of DNA and RNA increased with increase doses in the seedling hypocotyl of soybean and rape, Caf and EDTA post-treatment made them further higher than that of H 2 O-treatment. Meanwhile, the content of DNA and RNA in hypocotyl of soybean seedling was more than that of rape. Radioactive 3 H-TdR incorporation experiment showed γ-ray irradiated seeds induced unshunted DNA synthesis in the primary cultivated seeds of two crops, which was inhibited by Caf, EDTA and C + E post-treatment in the order of C + E>Caf>EDTA. Experiment also revealed irradiation and repair repressor post-treatment affected normal shunted DNA synthesis, postponed the cycle of cell division

  19. Uranium Leaching from Contaminated Soil Utilizing Rhamnolipid, EDTA, and Citric Acid

    Directory of Open Access Journals (Sweden)

    Sara Asselin

    2014-01-01

    Full Text Available Biosurfactants have recently gained attention as “green” agents that can be used to enhance the remediation of heavy metals and some organic matter in contaminated soils. The overall objective of this paper was to investigate rhamnolipid, a microbial produced biosurfactant, and its ability to leach uranium present in contaminated soil from an abandoned mine site. Soil samples were collected from two locations in northern Arizona: Cameron (site of open pit mining and Leupp (control—no mining. The approach taken was to first determine the total uranium content in each soil using a hydrofluoric acid digestion, then comparing the amount of metal removed by rhamnolipid to other chelating agents EDTA and citric acid, and finally determining the amount of soluble metal in the soil matrix using a sequential extraction. Results suggested a complex system for metal removal from soil utilizing rhamnolipid. It was determined that rhamnolipid at a concentration of 150 μM was as effective as EDTA but not as effective as citric acid for the removal of soluble uranium. However, the rhamnolipid was only slightly better at removing uranium from the mining soil compared to a purified water control. Overall, this study demonstrated that rhamnolipid ability to remove uranium from contaminated soil is comparable to EDTA and to a lesser extent citric acid, but, for the soils investigated, it is not significantly better than a simple water wash.

  20. Histological analysis of effects of 24% EDTA gel for nonsurgical treatment of periodontal tissues.

    Science.gov (United States)

    de Vasconcellos, Luana Marotta Reis; Ricardo, Lucilene Hernandes; Balducci, Ivan; de Vasconcellos, Luis Gustavo Oliveira; Carvalho, Yasmin Rodarte

    2006-12-01

    The aim of this study was to investigate, by means of histological and histomorphometric analysis, the effects of 24% ethylenediaminetetraacetic acid (EDTA) gel in periodontal tissue when used in combination with conventional periodontal treatment. Periodontitis was induced in the 2nd upper left permanent molars of 45 male Wistar rats by means of ligature. After 5 weeks, this was removed and debridement was performed. The animals were then randomly divided into 3 groups; group 1: mechanical treatment, group 2: mechanical treatment and EDTA gel application for 2 min, and group 3: mechanical treatment and placebo gel application for 2 min. After the treatment, rinsing was done with 0.9% saline solution for 1 min in all cases, followed by root notching in the deepest part of the pocket. After 4, 10, and 28 days the animals were sacrificed. The averages obtained were evaluated by means of test two-way analysis of variance (ANOVA) and Tukey statistical tests (P 24% EDTA gel did not interfere with periodontal tissue repair when used in combination with conventional periodontal treatment.

  1. Electrospun polyacrylonitrile nanofibers functionalized with EDTA for adsorption of ionic dyes

    Science.gov (United States)

    Chaúque, Eutilério F. C.; Dlamini, Langelihle N.; Adelodun, Adedeji A.; Greyling, Corinne J.; Ngila, J. Catherine

    2017-08-01

    The manipulation of nanofibers' surface chemistry could enhance their potential application toward the removal of ionic dyes in wastewater. For this purpose, surface modification of electrospun polyacrylonitrile (PAN) nanofibers with ethylenediaminetetraacetic acid (EDTA) and ethylenediamine (EDA) crosslinker was experimented. The functionalized EDTA-EDA-PAN nanofibers were characterized using Fourier transform infrared (FT-IR) spectroscopy, X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and Brunauer-Emmett-Teller (BET) technique. The impregnation of EDA and EDTA chelating agents on the surface of PAN changed the distribution of nanofibers as proximity is increased (accompanied by reduced softness), but the nanofibrous structure of the pristine PAN nanofibers was not substantially altered. Adsorption equilibrium studies were performed with Freundlich, Langmuir and Temkin isotherm models with the former providing better correlation to the experimental data. The modified PAN nanofibers showed efficient sorption of methyl orange (MO) and reactive red (RR) from aqueous synthetic samples, evinced by the maximum adsorption capacities (at 25 °C) of 99.15 and 110.0 mg g-1, respectively. The fabricated nanofibers showed appreciable removal efficiency of the target dye sorptives from wastewater. However, the presence of high metal ions content affected the overall extraction of dyes from wastewater due to the depletion of the adsorbent's active adsorptive sites.

  2. Laser Monitoring Of Phytoextraction Enhancement Of Lead Contaminated Soil Adopting EDTA And EDDS

    Science.gov (United States)

    Hassan, M.; Abdelhamied, M.; Hanafy, A. H.; Fantoni, R.; Harith, M. A.

    2011-09-01

    Removal of heavy metals (HMs) such as Pb from soil, wastewater, and air is essential for environment and human health. Phytoremediation is a well established technology based on the use of certain green plants for contaminants removal from soil, wastewater as well as air. Scented geranium, Pelargonium zonal, is a flowering plant recently used in HMs removal from contaminated soil. In the present work, EDTA (ethylenediaminetetraacetic acid) and EDDS (S, S-ethylenediaminedisuccinic acid) were used as chemical assistants providing higher Pb availability for extraction by plant roots. Lead was artificially added to the planting media, peatmoss, at different concentrations. Laser induced breakdown spectroscopy (LIBS) was used to follow up Pb relative concentrations in peatmoss as well as plant shoots, at different sampling times during the experiment period. Laser induced chlorophyll fluorescence (LICF), has been also used to evaluate chlorophyll formation and photosynthetic apparatus status in geranium plants. Such measurements were performed on geranium plants grown under various Pb levels, as well as EDTA and EDDS combinations. The combined effect of EDTA and EDDS was found to enhance Pb extraction with time. Good correlation was found between LICF results and chlorophyll (a) (Chl.a) concentrations in plant tissues extracted by chemical analysis.

  3. In vitro antimicrobial activity of a commercial ear antiseptic containing chlorhexidine and Tris-EDTA.

    Science.gov (United States)

    Guardabassi, Luca; Ghibaudo, Giovanni; Damborg, Peter

    2010-06-01

    Minimum bactericidal concentrations (MBCs) of a commercial ear antiseptic containing chlorhexidine 0.15% and Tris-EDTA (Otodine) were determined by broth microdilution for 150 isolates representing the most common pathogens associated with canine otitis. The microorganisms were classified into three groups according to their levels of susceptibility. The most susceptible group included Staphylococcus pseudintermedius, Malassezia pachydermatis, Streptococcus canis and Corynebacterium auriscanis, which were generally killed by 1 : 64 dilution of the antiseptic product (MBC = 23/0.8 microg/mL of chlorhexidine/Tris-EDTA). The most resistant organism was Proteus mirabilis, which survived up to 1 : 8 dilution of the product (MBC = 375/12 microg/mL). Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus displayed intermediate MBCs ranging between 188/6 and 47/1.5 microg/mL. Interestingly, S. pseudintermedius was more susceptible than S. aureus, and no significant difference was observed between meticillin-resistant and meticillin-susceptible isolates within each species, indicating that antiseptic use is unlikely to co-select for meticillin resistance. Although the concentrations required for killing (MBCs) varied considerably with microorganism type, the combination of chlorhexidine 0.15% and Tris-EDTA was active against all the pathogens most commonly involved in canine otitis.

  4. Characterization and adsorption mechanism of Zn2+ removal by PVA/EDTA resin in polluted water

    International Nuclear Information System (INIS)

    Zhang Yun; Li Yanfeng; Yang Liuqing; Ma Xiaojie; Wang Liyuan; Ye Zhengfang

    2010-01-01

    Batch adsorption experiments were conducted using a PVA/EDTA resin as an adsorbent to adsorb Zn(II) ions from single component system in which experimental parameters were studied including solution pH, contact time, adsorbent dose and initial metal ions concentration. The equilibrium isotherms were determined at pH 6 under constant ionic strength and at different temperatures. The results showed that the maximum removal of Zn(II) (99.8%) with 1 g L -1 of sorbent was observed at 40 mg L -1 at an initial pH value of 6. Removals of about 60-70% occurred in 15 min, and equilibrium was attained at around 30 min. The equilibrium data for the adsorption of Zn(II) on PVA/EDTA resin was tested with various adsorption isotherm models among which three models were found to be suitable for the Zn(II) adsorption. In addition, the kinetic adsorption fitted well to the pseudo-second-order model and the corresponding rate constants were obtained. Thermodynamic aspects of the adsorption process were also investigated. Furthermore a higher desorption efficiency of Zn(II) from the PVA/EDTA resin using acid treatment was available by more than 95%.

  5. Preparation and radiopharmaceutical control of 169Yb EDTA an agent for kidney function and scintigraphy

    International Nuclear Information System (INIS)

    Gulbaba, G.; Ozker; Tomek, F.

    1976-01-01

    169 Yb was produced by thermal neutron irradiation of Yb 2 O 3 in 1 MW research reactor at Cekmece Nuclear Research Center. 169 Yb-EDTA complex was then prepared with a sodium salt of EDTA. Radionuclidic and radiochemical purities of the compound were determined by gama spectral analysis and radiochromatography-electrophoresis following preparation. Ionic Yb(III) which accumulates at bone and liver was not observed on the radiochromatographic and electrophoretic analysis of the final compound. There was no separation of the label for two months of examination in order to determine stability of the compound. In conclusion, the labeled compound has been prepared for use in the external scanning of kidney and determining the glomerular filtration rate. The label appears to be firmly bound so that the agent can be stored for a reasonably long period as 31 days half-life of 169 Yb permits. Administration of the compound is safe from the stand point of radiation dose since a 30 micro-Ci 169 Yb-EDTA for a glomerular filtration study delivers no more than 0.4 mrad whole-body and 5 mrad kidney dose. (author)

  6. Citrate-capped gold nanoparticle electrophoretic heat production in response to a time-varying radiofrequency electric-field.

    Science.gov (United States)

    Corr, Stuart J; Raoof, Mustafa; Mackeyev, Yuri; Phounsavath, Sophia; Cheney, Matthew A; Cisneros, Brandon T; Shur, Michael; Gozin, Michael; McNally, Patrick J; Wilson, Lon J; Curley, Steven A

    2012-11-15

    The evaluation of heat production from gold nanoparticles (AuNPs) irradiated with radiofrequency (RF) energy has been problematic due to Joule heating of their background ionic buffer suspensions. Insights into the physical heating mechanism of nanomaterials under RF excitations must be obtained if they are to have applications in fields such as nanoparticle-targeted hyperthermia for cancer therapy. By developing a purification protocol which allows for highly-stable and concentrated solutions of citrate-capped AuNPs to be suspended in high-resistivity water, we show herein, for the first time, that heat production is only evident for AuNPs of diameters ≤ 10 nm, indicating a unique size-dependent heating behavior not previously observed. Heat production has also shown to be linearly dependent on both AuNP concentration and total surface area, and severely attenuated upon AuNP aggregation. These relationships have been further validated using permittivity analysis across a frequency range of 10 MHz to 3 GHz, as well as static conductivity measurements. Theoretical evaluations suggest that the heating mechanism can be modeled by the electrophoretic oscillation of charged AuNPs across finite length scales in response to a time-varying electric field. It is anticipated these results will assist future development of nanoparticle-assisted heat production by RF fields for applications such as targeted cancer hyperthermia.

  7. Developing suitable buffers to capture transport cycling behavior

    DEFF Research Database (Denmark)

    Madsen, Thomas; Schipperijn, Jasper; Christiansen, Lars Breum

    2014-01-01

    units (e.g., home-buffer-based neighborhoods) are not necessarily representative for environmental exposure. An increased understanding of appropriate neighborhoods is needed. GPS cycling tracks from 78 participants for 7 days form the basis for the development and testing of different neighborhood...... buffers for transport cycling. The percentage of GPS points per square meter was used as indicator of the effectiveness of a series of different buffer types, including home-based network buffers, shortest route to city center buffers, and city center-directed ellipse-shaped buffers. The results show...... center-directed ellipse-shaped buffers yielded better results than traditional home-based network buffer types. The ellipse-shaped buffer types could therefore be considered an alternative to more traditional buffers or administrative units in future studies of transport cycling behavior....

  8. The impact of citrate introduction at UK syringe exchange programmes: a retrospective cohort study in Cheshire and Merseyside, UK

    Directory of Open Access Journals (Sweden)

    Wareing Michelle

    2007-12-01

    Full Text Available Abstract Background In 2003, it became legal in the UK for syringe exchange programmes (SEPs to provide citrate to injecting drug users to solubilise heroin. Little work has been undertaken on the effect of policy change on SEP function. Here, we examine whether the introduction of citrate in Cheshire and Merseyside SEPs has altered the number of heroin/crack injectors accessing SEPs, the frequency at which heroin/crack injectors visited SEPs and the number of syringes dispensed. Methods Eleven SEPs in Cheshire and Merseyside commenced citrate provision in 2003. SEP-specific data for the six months before and six months after citrate was introduced were extracted from routine monitoring systems relating to heroin and crack injectors. Analyses compared all individuals attending pre and post citrate and matched analyses only those individuals attending in both periods (defined as 'longitudinal attenders'. Non-parametric tests were used throughout. Results Neither new (first seen in either six months period nor established clients visited SEPs more frequently post citrate. New clients collected significantly less syringes per visit post citrate, than pre citrate (14.5,10.0; z = 1.992, P Conclusion The introduction of citrate did not negatively affect SEP attendance. 'Longitudinal attenders' visited SEPs more frequently post citrate, providing staff with greater opportunity for intervention and referral. As the number of syringes they collected each visit remained unchanged the total number of clean syringes made available to this group of injectors increased very slightly between the pre and post citrate periods. However, new clients collected significantly less syringes post citrate than pre citrate, possibly due to staff concerns regarding the amount of citrate (and thus syringes to dispense safely to new clients. These concerns should not be allowed to negatively impact on the number of syringes dispensed.

  9. Buffer of Events as a Markovian Process

    International Nuclear Information System (INIS)

    Berdugo, J.; Casaus, J.; Mana, C.

    2001-01-01

    In Particle and Asro-Particle Physics experiments, the events which get trough the detectors are read and processes on-line before they are stored for a more detailed processing and future Physics analysis. Since the events are read and, usually, processed sequentially, the time involved in these operations can lead to a significant lose of events which is, to some extent, reduced by using buffers. We present an estimate of the optimum buffer size and the fraction of events lost for a simple experimental condition which serves as an introductory example to the use of Markow Chains.(Author)

  10. Buffer of Events as a Markovian Process

    Energy Technology Data Exchange (ETDEWEB)

    Berdugo, J.; Casaus, J.; Mana, C.

    2001-07-01

    In Particle and Asro-Particle Physics experiments, the events which get trough the detectors are read and processes on-line before they are stored for a more detailed processing and future Physics analysis. Since the events are read and, usually, processed sequentially, the time involved in these operations can lead to a significant lose of events which is, to some extent, reduced by using buffers. We present an estimate of the optimum buffer size and the fraction of events lost for a simple experimental condition which serves as an introductory example to the use of Markow Chains.(Author)

  11. Emplacement of small and large buffer blocks

    International Nuclear Information System (INIS)

    Saari, H.; Nikula, M.; Suikki, M.

    2010-05-01

    The report describes emplacement of a buffer structure encircling a spent fuel canister to be deposited in a vertical hole. The report deals with installability of various size blocks and with an emplacement gear, as well as evaluates the achieved quality of emplacement and the time needed for installing the buffer. Two block assembly of unequal size were chosen for examination. A first option involved small blocks, the use of which resulted in a buffer structure consisting of small sector blocks 200 mm in height. A second option involved large blocks, resulting in a buffer structure which consists of eight blocks. In these tests, the material chosen for both block options was concrete instead of bentonite. The emplacement test was a three-phase process. A first phase included stacking a two meter high buffer structure with small blocks for ensuring the operation of test equipment and blocks. A second phase included installing buffer structures with both block options to a height matching that of a canister-encircling cylindrical component. A third phase included testing also the installability of blocks to be placed above the canister by using small blocks. In emplacement tests, special attention was paid to the installability of blocks as well as to the time required for emplacement. Lifters for both blocks worked well. Due to the mass to be lifted, the lifter for large blocks had a more heavy-duty frame structure (and other lifting gear). The employed lifters were suspended in the tests on a single steel wire rope. Stacking was managed with both block sizes at adequate precision and stacked-up towers were steady. The stacking of large blocks was considerably faster. Therefore it is probably that the overall handling of the large blocks will be more convenient at a final disposal site. From the standpoint of reliability in lifting, the small blocks were safer to install above the canister. In large blocks, there are strict shape-related requirements which are

  12. Grass buffers for playas in agricultural landscapes: An annotated bibliography

    Science.gov (United States)

    Melcher, Cynthia P.; Skagen, Susan K.

    2005-01-01

    This bibliography and associated literature synthesis (Melcher and Skagen, 2005) was developed for the Playa Lakes Joint Venture (PLJV). The PLJV sought compilation and annotation of the literature on grass buffers for protecting playas from runoff containing sediments, nutrients, pesticides, and other contaminants. In addition, PLJV sought information regarding the extent to which buffers may attenuate the precipitation runoff needed to fill playas, and avian use of buffers. We emphasize grass buffers, but we also provide information on other buffer types.

  13. Retention of ionisable compounds on high-performance liquid chromatography. XV. Estimation of the pH variation of aqueous buffers with the change of the acetonitrile fraction of the mobile phase.

    Science.gov (United States)

    Subirats, Xavier; Bosch, Elisabeth; Rosés, Martí

    2004-12-03

    The most commonly used mobile phases in reversed-phase high-performance liquid chromatography (RP-HPLC) are hydro-organic mixtures of an aqueous buffer and an organic modifier. The addition of this organic solvent to buffered aqueous solutions involves a variation of the buffer properties (pH and buffer capacity). In this paper, the pH variation is studied for acetic acid-acetate, phosphoric acid-dihydrogenphosphate-hydrogenphosphate, citric acid-dihydrogencitrate-citrate, and ammonium-ammonia buffers. The proposed equations allow pH estimation of acetonitrile-water buffered mobile phases up to 60% (v/v) of organic modifier and initial aqueous buffer concentrations between 0.001 and 0.1 mol L(-1), from the initial aqueous pH. The estimated pH variation of the mobile phase and the pKa variation of the analytes allow us to predict the degree of ionisation of the analytes and from this and analyte hydrophobicities, to interpret the relative retention and separation of analyte mixtures.

  14. Oxidation of aqueous EDTA and associated organics and coprecipitation of inorganics by ambient iron-mediated aeration.

    Science.gov (United States)

    Englehardt, James D; Meeroff, Daniel E; Echegoyen, Luis; Deng, Yang; Raymo, Françisco M; Shibata, Tomoyuki

    2007-01-01

    Cationic metal and radionuclide contaminants can be extracted from soils to groundwater with sequestering agents such as EDTA. However, EDTA must then be removed fromthe groundwater, by advanced oxidation or specialized biological treatment. In this work, aqueous individual metal-EDTA solutions were aerated with steel wool for 25 h, at ambient pH, temperature, and pressure. Removal of approximately 99% of EDTA (0.09-1.78 mM); glyoxylic acid (0.153 mM); chelated Cd2+ (0.94 and 0.0952 mM), Pb2+ (0.0502 mM), and Hg2+ (0.0419 mM); and free chromate and vanadate was shown. EDTA was oxidized to glyoxylic acid and formaldehyde, and metals/metalloids were coprecipitated together with iron oxyhydroxide floc. Free arsenite and arsenate were each removed at 99.97%. Free Sr2+, and chelated Ni2+ were removed at 92% and 63%, respectively. Similar removals were obtained from mixtures, including 99.996+/-0.004% removal of total arsenic (95% confidence). Traces of iminodiacetic acid, nitrilotriacetic acid, and ethylenediaminetriacetic acid were detected after 25 h. Results are consistent with first-order, solution-phase oxidation of EDTA and glyoxylic acid by ferryl ion and H202, respectively, with inhibition due to sludge accumulation, and equilibrium metal coprecipitation. This ambient process, to our knowledge previously unknown, agrees with recently reported findings and shows promise for remediation of metals, metalloids, and radionuclides in wastewater, soil, and sediment.

  15. Using electrocoagulation for metal and chelant separation from washing solution after EDTA leaching of Pb, Zn and Cd contaminated soil.

    Science.gov (United States)

    Pociecha, Maja; Lestan, Domen

    2010-02-15

    Electrocoagulation with an Al sacrificial anode was tested for the separation of chelant and heavy metals from a washing solution obtained after leaching Pb (3200 mg kg(-1)), Zn (1100 mg kg(-1)), and Cd (21 mg kg(-1)) contaminated soil with EDTA. In the electrochemical process, the sacrificial anode corroded to release Al(3+) which served as coagulant for precipitation of chelant and metals. A constant current density of 16-128 mAc m(-2) applied between the Al anode and the stainless-steel cathode removed up to 95% Pb, 68% Zn and 66% Cd from the soil washing solution. Approximately half of the initial EDTA remained in the washing solution after treatment, up to 16.3% of the EDTA was adsorbed on Al coagulant and precipitated, the rest of the EDTA was degraded by anodic oxidation. In a separate laboratory-scale remediation experiment, we leached a soil with 40 mmol EDTA per kg of soil and reused the washing solution (after electrocoagulation) in a closed loop. It removed 53% of Pb, 26% of Zn and 52% of Cd from the soil. The discharge solution was clear and colourless, with pH 7.52 and 170 mg L(-1) Pb, 50 mg L(-1) Zn, 1.5 mg L(-1) Cd and 11 mM EDTA.

  16. Oxidative degradation stability and hydrogen sulfide removal performance of dual-ligand iron chelate of Fe-EDTA/CA.

    Science.gov (United States)

    Miao, Xinmei; Ma, Yiwen; Chen, Zezhi; Gong, Huijuan

    2017-09-05

    Catalytic oxidation desulfurization using chelated iron catalyst is an effective method to remove H 2 S from various gas streams including biogas. However, the ligand of ethylenediaminetetraacetic acid (EDTA), which is usually adopted to prepare chelated iron catalyst, is liable to be oxidative degraded, and leads to the loss of desulfurization performance. In order to improve the degradation stability of the iron chelate, a series of iron chelates composed of two ligands including citric acid (CA) and EDTA were prepared and the oxidative degradation stability as well as desulfurization performance of these chelated iron catalysts were studied. Results show that the iron chelate of Fe-CA is more stable than Fe-EDTA, while for the desulfurization performance, the situation is converse. For the dual-ligand iron chelates of Fe-EDTA/CA, with the increase of mol ratio of CA to EDTA in the iron chelate solution, the oxidative degradation stability increased while the desulfurization performance decreased. The results of this work showed that Fe-EDTA/CA with a mol ratio of CA:EDTA = 1:1 presents a relative high oxidative degradation stability and an acceptable desulfurization performance with over 90% of H 2 S removal efficiency.

  17. Reducing the potential for migration of radioactive waste: Aqueous thermal degradation of the chelating agent disodium EDTA

    International Nuclear Information System (INIS)

    Boles, J.S.; Ritchie, K.; Crerar, D.A.

    1987-01-01

    Ethylenediaminetetraacetic acid (EDTA), a common component of cleaning solutions used for decontamination of radioactive equipment, has been associated with increased migration of radionuclides into local groundwaters at some radwaste disposal sites. It has been proposed that predisposal thermal degradation of EDTA-containing aqueous solutions may reduce the potential for chelate-enhanced mobilization of radionuclides at these sites. Aqueous thermal degradation experiments with disodium EDTA have shown that the compound degrades rapidly at 200 0 C with an activation energy of 114.3 +- 7.87 kJ/mol, and forms the decomposition product methyliminodiacetic acid (MIDA). A comparison of the values for stability constants of transition metal and actinide complexes with EDTA, MIDA, and two other reported degradation products, indicates that the chelating efficiency of the degradation products is 6 to 22 orders of magnitude lower than that of EDTA at 25 0 C. It is concluded that aqueous thermal degradation should significantly reduce the overall chelating efficiency of EDTA-containing solutions

  18. Optimizing the molarity of a EDTA washing solution for saturated-soil remediation of trace metal contaminated soils

    International Nuclear Information System (INIS)

    Andrade, M.D.; Prasher, S.O.; Hendershot, W.H.

    2007-01-01

    Three experiments were conducted to optimize the use of ethylenediaminetetraacetic acid (EDTA) for reclaiming urban soils contaminated with trace metals. As compared to Na 2 EDTA (NH 4 ) 2 EDTA extracted 60% more Zn and equivalent amounts of Cd, Cu and Pb from a sandy loam. When successively saturating and draining loamy sand columns during a washing cycle, which submerged it once with a (NH 4 ) 2 EDTA wash and four times with deionised water, the post-wash rinses largely contributed to the total cumulative extraction of Cd, Co, Cr, Cu, Mn, Ni, Pb and Zn. Both the washing solution and the deionised water rinses were added in a 2:5 liquid to soil (L:S) weight ratio. For equal amounts of EDTA, concentrating the washing solution and applying it and the ensuing rinses in a smaller 1:5 L:S weight ratio, instead of a 2:5 L:S weight ratio, increased the extraction of targeted Cr, Cu, Ni, Pb and Zn. - A single EDTA addition is best utilised in a highly concentrated washing solution given in a small liquid to soil weight ratio

  19. Effect of EDTA and citric acid on phytoremediation of Cr- B[a]P-co-contaminated soil.

    Science.gov (United States)

    Chigbo, Chibuike; Batty, Lesley

    2013-12-01

    Polycyclic aromatic hydrocarbons and heavy metals in the environment are a concern, and their removal to acceptable level is required. Phytoremediation, the use of plants to treat contaminated soils, could be an interesting alternative to conventional remediation processes. This work evaluates the role of single and combined applications of chelates to single or mixed Cr + benzo[a]pyrene (B[a]P)-contaminated soil. Medicago sativa was grown in contaminated soil and was amended with 0.3 g citric acid, 0.146 g ethylenediaminetetraacetic acid (EDTA), or their combination for 60 days. The result shows that in Cr-contaminated soil, the application of EDTA + citric acid significantly (psoil. The soluble Cr concentration in single Cr or Cr + B[a]P-contaminated soil was enhanced with the amendment of all chelates; however, only the application of citric acid in Cr-contaminated soil (44 %) or EDTA and EDTA + citric acid in co-contaminated soil increased the removal of Cr from the soil (34 and 54 %, respectively). The dissipation of B[a]P in single B[a]P-contaminated soil was effective even without planting and amendment with chelates, while in co-contaminated soil, it was related to the application of either EDTA or EDTA + citric acid. This suggests that M. sativa with the help of chelates in single or co-contaminated soil can be effective in phytoextraction of Cr and promoting the biodegradation of B[a]P.

  20. Effect of sildenafil citrate (Viagra) on coronary flow in normal subjects.

    Science.gov (United States)

    Ishikura, Fuminobu; Beppu, Shintaro; Ueda, Hiroaki; Nehra, Ajay; Khandheria, Bijoy K

    2008-01-01

    The purpose of this study was to evaluate the effect of sildenafil citrate (Viagra) on coronary function in normal subjects. The study assessed mean blood pressure, left anterior descending coronary artery (LAD) flow, and echocardiographic variables before and 30 and 60 minutes after taking 50 mg of sildenafil citrate. The mean velocity of LAD flow was assessed with Doppler flow imaging. The study subjects were 6 healthy male volunteers (mean age 37 years). The mean velocity of LAD flow increased 60 minutes after taking sildenafil citrate, but there were no other changes. Two volunteers felt mild flashing and one had mild headache during the study. Sildenafil citrate caused vasodilatation in a normal coronary artery without systemic pressure drops. These results suggest that the agent itself did not have negative effects on the heart in normal subjects.

  1. Influence of temperature on flavour compound production from citrate by Lactobacillus rhamnosus ATCC 7469.

    Science.gov (United States)

    De Figueroa, R M; Oliver, G; Benito de Cárdenas, I L

    2001-03-01

    The citrate utilization by Lactobacillus rhamnosus ATCC 7469 was found to be temperature-dependent. The maximum citrate utilization and incorporation of [1,5-14C]citrate rate were observed at 37 degreesC. At this temperature, maximum citrate lyase activity and specific diacetyl and acetoin production (Y(DA%)) were observed. The high levels of alpha-acetolactate synthase and low levels of diacetyl reductase, acetoin reductase and L-lactate dehydrogenase found at 37 degreesC led to an accumulation of diacetyl and acetoin. Optimum lactic acid production was observed at 45 degreesC, according to the high lactate dehydrogenase activity. The NADH oxidase activity increased with increasing culture temperature from 22 degreesC to 37 degreesC. Thus there are greater quantities of pyruvate available for the production of alpha-acetolactate, diacetyl and aceotin, and less diacetyl and acetoin are reduced.

  2. SILDENAFIL CITRATE INDUCED RETINAL TOXICITY-ELECTRORETINOGRAM, OPTICAL COHERENCE TOMOGRAPHY, AND ADAPTIVE OPTICS FINDINGS.

    Science.gov (United States)

    Yanoga, Fatoumata; Gentile, Ronald C; Chui, Toco Y P; Freund, K Bailey; Fell, Millie; Dolz-Marco, Rosa; Rosen, Richard B

    2018-02-27

    To report a case of persistent retinal toxicity associated with a high dose of sildenafil citrate intake. Single retrospective case report. A 31-year-old white man with no medical history presented with complaints of bilateral multicolored photopsias and erythropsia (red-tinted vision), shortly after taking sildenafil citrate-purchased through the internet. Patient was found to have cone photoreceptor damage, demonstrated using electroretinogram, optical coherence tomography, and adaptive optics imaging. The patient's symptoms and the photoreceptor structural changes persisted for several months. Sildenafil citrate is a widely used erectile dysfunction medication that is typically associated with transient visual symptoms in normal dosage. At high dosage, sildenafil citrate can lead to persistent retinal toxicity in certain individuals.

  3. Photometric determination of the composition and dissociation constants of niobium (5) citrate complexes

    International Nuclear Information System (INIS)

    Grigor'eva, V.V.; Golubeva, I.V.

    1979-01-01

    Niobium (5) citrate complexes in aqueous solution (pH 1-6) are investigated. To determine the complexes composition the metal-indicator method has been applied. Experimental data have been treated by the method of equilibrium shift using somewhat changed variant of the metal-indicator method. The complex ion charge in the solution has been determined by the ion-exchange method. Dissociation constants of citrate complexes have been determined photometrically

  4. Effects of citrate on hexavalent chromium reduction by structural Fe(II) in nontronite

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Xiaolei; Dong, Hailiang; Yang, Xuewei; Kovarik, Libor; Chen, Yu; Zeng, Qiang

    2018-02-01

    Iron-bearing clay minerals and organic matter are two important components in natural environments that influence hexavalent chromium (Cr(VI)) reduction. Previous studies have shown that organic ligands could influence Cr(VI) reduction by aqueous Fe2+ and pyrite. However, the effects of organic ligands on Cr(VI) reduction by structural Fe(II) in clays are not well understood. In this study, the effects of citrate on Cr(VI) reduction by nontronite (NAu-2) were investigated under near neutral pH condition (pH=6). Our results showed that the presence of citrate decreased the rate but increased the amount of Cr(VI) reduction by structural Fe(II) in NAu-2. The decreased reaction rate was likely due to competitive sorption of citrate and polyanionic dichromate (Cr2O7- ), because sorption of dichromate appeared to be the first step for subsequent Cr(VI) reduction. The increased amount of Cr(VI) reduction in the presence of citrate was likely because citrate provided additional reducing power through ligand-metal electron transfer in the presence of soluble Fe 3+ derived from dissolution of reduced NAu-2. Soluble Cr(III)-citrate complex was the possible form of reduced chromium when citrate was present. In contrast, nanometer-sized Cr2O3 particles were the product of Cr(VI) reduction by reduced NAu-2 without citrate. Our study highlights the importance of organic ligands on Cr(VI) reduction and immobilization when iron-bearing clay minerals are applied to treat Cr(VI) contaminant in organic matter rich environments.

  5. High performance liquid chromatographic-mass spectrometric assay for the quantitation of BMS-204352 in dog K(3)EDTA plasma.

    Science.gov (United States)

    Yao, Ming; Mantha, Subbarao; Shah, Vinod R; Vachharajani, Nimish N; Arnold, Mark E; Pursley, Janice M; Srinivas, Nuggehally R

    2002-05-01

    A high performance liquid chromatographic-mass spectrometric (LC/MS) assay was developed and validated for the determination of BMS-204352 in dog K(3)EDTA plasma. A 0.5 mL aliquot of control plasma was spiked with BMS-204352 and internal standard (IS) and buffered with 1 mL of 5 mM ammonium acetate. The mixture was then extracted with 3 mL of toluene. After separation and evaporation of the organic phase to dryness using nitrogen at 40 degrees C, the residue was reconstituted in the mobile phase and 25 microL of the sample were injected onto a Hypersil C(18) column (2 x 50 mm; 3 microm) at a flow rate of 0.5 mL/min. The mobile phase was consisted of two solvent mixtures (A and B). Solvent A was composed of 5 mM ammonium acetate and 0.1% triethylamine in 75:25 v/v water:methanol, pH adjusted to 5.5 with glacial acetic acid, and solvent B was 5 mM ammonium acetate in methanol. A linear gradient system was used to elute the analytes. The mass spectrometer was programmed to admit the de-protonated molecules at m/z 352.7 (IS) and m/z 357.9 (BMS-204352). Standard curves of BMS-204352 were linear (r(2) > or = 0.998) over the concentration range of 0.5-1000 ng/mL. The mean predicted quality control (QC) concentrations deviated less than 5.1% from the corresponding nominal values (ie 4, 80, 400 and 2000 ng/mL); the within- and between-assay precision of the assay were within 5.5% relative standard deviation. Stability of BMS-204352 was confirmed after at least three freeze/thaw cycles and BMS-204532 was stable in dog plasma when stored frozen at or below -20 degrees C for at least 16 weeks in spiked QC samples and for at least 4 1/2 weeks for in vivo study samples. BMS-204352 and IS were stable in the injection solvent at room temperature for at least 24 h. The assay was applied to delineate the pharmacokinetic disposition of BMS-204352 in dogs following a single intravenous dose administration. In conclusion, the assay is accurate, precise, specific, sensitive and

  6. The buffer effect in neutral electrolyte supercapacitors

    DEFF Research Database (Denmark)

    Thrane Vindt, Steffen; Skou, Eivind M.

    2016-01-01

    The observation that double-layer capacitors based on neutral aqueous electrolytes can have significantly wider usable potential windows than those based on acidic or alkaline electrolytes is studied. This effect is explained by a local pH change taking place at the electrode surfaces, leading...... potassium nitrate as the electrolyte and potassium phosphates as the buffer system....

  7. Buffer gas cooling and mixture analysis

    Science.gov (United States)

    Patterson, David S.; Doyle, John M.

    2018-03-06

    An apparatus for spectroscopy of a gas mixture is described. Such an apparatus includes a gas mixing system configured to mix a hot analyte gas that includes at least one analyte species in a gas phase into a cold buffer gas, thereby forming a supersaturated mixture to be provided for spectroscopic analysis.

  8. Buffer Overflow Period in a MAP Queue

    Directory of Open Access Journals (Sweden)

    Andrzej Chydzinski

    2007-01-01

    Full Text Available The buffer overflow period in a queue with Markovian arrival process (MAP and general service time distribution is investigated. The results include distribution of the overflow period in transient and stationary regimes and the distribution of the number of cells lost during the overflow interval. All theorems are illustrated via numerical calculations.

  9. Body Buffer Zone and Proxemics in Blocking.

    Science.gov (United States)

    Stockwell, John C.; Bahs, Clarence W.

    This paper investigates the effect of personal body buffer zones on compositional arrangements staged by novice directors. Relationships between directors' concepts of personal space and their projection of its dimensions into staging are studied through the use of a variety of proximity measures--distance, area angles of approach, and physical…

  10. Effects of calcium disodium EDTA and meso-2,3-dimercaptosuccinic acid on tissue concentrations of lead for use in treatment of calves with experimentally induced lead toxicosis.

    Science.gov (United States)

    Meldrum, James B; Ko, Kam W

    2003-06-01

    To compare the efficacy of calcium disodium EDTA (CaNa2EDTA) and meso-2,3-dimercaptosuccinic acid (DMSA) in reducing concentrations of lead in selected tissues for use in treatment of calves with experimentally induced lead toxicosis. 19 sexually intact male Holstein calves that weighed 35 to 60 kg. Calves were randomly assigned to 1 of 5 treatment groups: group 1, control calves; group 2, lead only; group 3, lead and EDTA; group 4, lead and DMSA; and group 5, lead, EDTA, and DMSA. Calves in groups 2 to 5 were dosed daily with lead (5 mg/kg, PO) for 10 days. Doses of EDTA (100 mg/kg) and DMSA (25 mg/kg) were administered IV once daily for 4 consecutive days beginning on day 11. Effects of the chelators on lead concentrations in the liver, kidneys, testes, muscles, bones, and brain were compared among the various groups. Compared with the effects of EDTA, DMSA greatly reduced lead concentrations in renal and hepatic tissues. We did not detect significant differences for the effects of EDTA or DMSA on lead concentrations in the testes; there was an adverse interaction of EDTA with DMSA that caused an increase in lead concentrations in the testes. DMSA is much more effective than EDTA in removing lead from renal and hepatic tissues in calves. Use of DMSA in calves with lead intoxication appears to be a viable treatment option. Combining DMSA and EDTA as a treatment modality in calves did not offer any advantages.

  11. HYDROTALSIT Zn-Al-EDTA SEBAGAI ADSORBEN UNTUK POLUTAN ION Pb(II DI LINGKUNGAN Zn-Al-EDTA Hydrotalcite as Adsorbent for Pb(II Ion Pollutant in The Environment

    Directory of Open Access Journals (Sweden)

    Roto Roto

    2015-07-01

    Full Text Available ABSTRAK Polusi ion Pb(II di dalam lingkungan perairan cenderung naik seiring peningkatan jumlah industri smelter dan daur ulang aki bekas. Penelitian ini bertujuan untuk menguji kemampuan hidrotalsit Zn-Al-EDTA sebagai adsorben ion Pb(II dalam air secara mendalam. Hidrotalsit Zn-Al-NO3 disintesis dengan metode kopresipitasi dan hidrotermal pada temperatur 100 °C selama 15 jam. Hidrotalsit Zn-Al-EDTA diperoleh dengan penukaran ion. Keasaman larutan, kinetika dan kapasitas adsorpsi diteliti. Hidrotalsit Zn-Al-EDTA memiliki d003 sebesar 14,52 Å sementara Zn-Al-NO3 sebesar 8,90 Å. Spektra FTIR menunjukkan keberadaan serapan gugus C=O pada bilangan gelombang 1684,77 cm-1. Kondisi optimum adsorpsi ion Pb(II terjadi pada pH 4, waktu kontak 60 menit dan kapasitas adsorpsi diperoleh 2,07 mg/g pada konsentrasi awal 10 mg/L dengan berat adsorben 0,100 g. Adsorpsi ion Pb(II oleh hidrotalsit Zn-Al-EDTA mengikuti reaksi pseudo orde dua dengan tetapan laju adsorpsi sebesar 8,90 g mmol-1min-1. Adsorpsi ion Pb(II oleh Zn-Al-EDTA terjadi karena  pembentukan khelat Pb-EDTA di dalam struktur hidrotalsit. Hasil ini diharapkan mampu memberikan kontribusi yang lebih luas di dalam pengendalian konsentrasi Pb(II di lingkungan. ABSTRACT Polution by Pb(II ion in the water environment tends to increase due the increase in the number of lead smelter and lead acid battery recycling industries. This work aims at studying in details the ability of Zn-Al-EDTA hydrotalcite as adsorbent for Pb(II ion in the environment. The Zn-Al-NO3 hydrotalcite was synthesized first by coprecipitation method followed by hydrothermal treatment at 100 °C for 15 h. The Zn-Al-EDTA hydrotalcite was later obtained by ion exchange process. The solution pH, kinetics and adsorption capacity were studied. The XRD data showed that Zn-Al-EDTA and Zn-Al-NO3 hydrotalcites have d003 of 14.52 and 8.90 Å, respectively. The FTIR spectra suggested that C=O group was observed with absorption band at 1684

  12. Comparison of technetium-99m methoxyisobutylisonitrile and gallium-67 citrate scanning in the assessment of lymphomas

    International Nuclear Information System (INIS)

    Ziegels, P.; Nocaudie, M.; Huglo, D.; Deveaux, M.; Detourmignies, L.; Wattel, E.; Marchandise, X.

    1995-01-01

    The aim of this study was to compare the value of scintigraphy using technetium-99m methoxy-isobutylisonitrile (MIBI) with that of scintigraphy using gallium-67 citrate in the assessment of Hodgkin's disease and non-Hodgkin's lymphoma and to relate these results with those of CT scan and MRI. Fifty-eight patients were included either for a follow-up examination or for monitoring of their treatment. Twenty-three residual masses were studied. A whole-body scan was performed, followed by single-photon emission computed tomography (SPET) 20 min after injection of 740 MBq of 99m Tc-MIBI and 72 h after injection of 185 MBq of 67 Ga citrate. The overall sensitivity of 99m Tc-MIBI and 67 Ga citrate was 71% and 68%, respectively, and the overall specificity was 76% and 44%, respectively. For residual masses, the sensitivity was 44% with both tracers and the specificity was 80% with 99m Tc-MIBI and 53% with 67 Ga citrate. The positive predictive values were 85% and 68% and the negative predictive values were 59% and 44%, respectively. The signal-to-background ratio was 1.5 for 99m Tc-MIBI and 2 for 67 Ga citrate. At present, 99m Tc-MIBI cannot replace 67 Ga citrate in the assessment of lymphomas. (orig.)

  13. Sildenafil citrate (Viagra) enhances vasodilatation by atrial natriuretic peptide in normal dogs.

    Science.gov (United States)

    Ishikura, Fuminobu; Beppu, Shintaro; Asanuma, Toshihiko; Seward, James B; Khandheria, Bijoy K

    2007-12-01

    Sildenafil citrate (Viagra) is a selective inhibitor of cyclic guanosine monophosphate (cGMP)-specific phosphodiesterase type 5, which might enhance the vasorelaxant and natriuretic actions of atrial natriuretic peptide (ANP) in patients with heart failure. The objective of this study was to examine the combined effect of Viagra on hemodynamic changes during infusion of exogenous ANP. Healthy male beagles were used to assess systemic blood pressure, pulmonary artery pressure (PAP), and plasma levels of cGMP. After hemodynamic variables were measured, 0.1 microg.kg(-1).min(-1) of ANP was given during this study. One hour after initiating infusion of ANP, 2 mg/kg of sildenafil citrate or vehicle was given orally via a nasogastric tube. Hemodynamic changes were measured before and 1 h after these administrations. Mean systemic and PAP decreased during infusion of ANP, and further decreased after sildenafil citrate administration, however, mean systemic blood pressure decreased within 10 mmHg. Plasma levels of cGMP also increased after sildenafil citrate administration. In normal dogs, sildenafil citrate enhances the vasodilator effect of ANP by increasing the cGMP level, however, the concomitant use of sildenafil citrate with ANP will not induce severe hypotension.

  14. Is it safe to prescribe clomiphene citrate without ultrasound monitoring facilities?

    LENUS (Irish Health Repository)

    Coughlan, C

    2010-05-01

    The majority of triplet and higher order multiple pregnancies now result from ovulation induction\\/superovulation rather than in vitro fertilisation. However, clomiphene citrate is still widely prescribed by gynaecologists and general practitioners who do not have access to ultrasound monitoring. The objective of our study was to determine the prevalence of multifollicular development with different doses of clomiphene citrate. A retrospective review of transvaginal ultrasound monitoring of 425 cycles in 182 women receiving clomiphene citrate from January 2002 to December 2003, was studied. Three or more follicles of >or= 14 mm were identified in 58 cycles (14%). Patients received 50 mg of clomiphene citrate in 52 of these 58 cycles and 25 mg in the remaining six. One patient was noted to have developed five follicles and 10 patients developed four follicles. One patient developed six follicles, despite receiving only 25 mg clomiphene citrate daily. It was concluded that a significant number of women (14%) developed three or more follicles, despite receiving low doses of clomiphene citrate.

  15. Gallium-67 citrate imaging for the assessment of radiation pneumonitis

    International Nuclear Information System (INIS)

    Kataoka, Masaaki

    1989-01-01

    In order to evaluate its usefulness in the assessment of radiation pneumotinis, gallium-67 citrate ( 67 Ga) imaging was performed before and after radiation therapy (RT) on 103 patients with lung cancer. In 23 patients with radiation pneumonitis detected radiographically, abnormal 67 Ga uptake in sites other than tumors was found in all post-RT 67 Ga lung images. Three patterns of uptake were found: (A) focal uptake corresponding to the RT field (n=10); (B) diffuse uptake including the RT field (n=4); and (C) diffuse uptake outside the RT field (n=9). The area of 67 Ga uptake was consistent with that of interstitial pneumonitis as revealed histopathologically in 7 cases. 67 Ga uptake in pattern (C) was an indicator of poor prognosis for the patients with radiation pneumonitis. 67 Ga uptake in the patients with reversible pneumonitis disappeared with steroid therapy. Sixteen (20%) of 80 asymptomatic patients, in whose chest radiographs there was no finding of radiation pneumonitis, showed transient 67 Ga uptake. These were considered to occur in the subclinical radiation pneumonitis. These data suggest that 67 Ga imaging is more sensitive than chest radiography in the detection of radiation pneumonitis and is useful in the assessment of the extent and clinical course of radiation pneumonitis. (author)

  16. Gallium-67 citrate imaging in underground coal miners

    International Nuclear Information System (INIS)

    Kanner, R.E.; Barkman, H.W. Jr.; Rom, W.N.; Taylor, A.T. Jr.

    1985-01-01

    Twenty-two underground coal workers with 27 or more years of coal dust exposure were studied with gallium-67 citrate (Ga-67) imaging. Radiographic evidence of coal workers indicates that pneumoconiosis (CWP) was present in 12 subjects. The Ga-67 scan was abnormal in 11 of 12 with, and 9 of 10 without, CWP. The Ga-67 uptake index was significantly correlated with total dust exposure (p less than 0.01) and approached significant correlation with the radiographic profusion of the nodules (0.10 greater than p greater than 0.05). There was no correlation between Ga-67 uptake and spirometric function, which was normal in this group of patients; furthermore, increased lung uptake of gallium did not indicate a poor prognosis in subjects no longer exposed to coal dust. While coal dust exposure may be associated with positive Ga-67 lung scan in coal miners with many years of coal dust exposure, the scan provided no information not already available from a careful exposure history and a chest radiograph. Since Ga-67 scanning is a relatively expensive procedure the authors would recommend that its use in subjects with asymptomatic CWP be limited to an investigative role and not be made part of a routine evaluation

  17. Anticaries effect of dentifrices with calcium citrate and sodium trimetaphosphate

    Directory of Open Access Journals (Sweden)

    Alberto Carlos Botazzo Delbem

    2012-02-01

    Full Text Available Because of the growing concerns regarding fluoride ingestion by young children and dental fluorosis, it is necessary to develop new dentifrices. OBJECTIVE: The aim of this study was to evaluate the effect of dentifrices with calcium citrate (Cacit and sodium trimetaphosphate (TMP on enamel demineralization. MATERIAL AND METHODS: Enamel blocks (n=70, previously selected through surface hardness analysis, were submitted to daily treatment with dentifrices diluted in artificial saliva and to a pH-cycling model. The fluoride concentration in dentifrices was 0, 250, 450, 550, 1,000 and 1,100 µg F/g. CrestTM was used as a positive control (1,100 mg F/g. Cacit (0.25% and TMP (0.25% were added to dentifrices with 450 and 1,000 µg F/g. Surface hardness was measured again and integrated loss of subsurface hardness and fluoride concentration in enamel were calculated. Parametric and correlation tests were used to determine difference (p0.05. CONCLUSIONS: Dentifrices with 450 and 1,000 µg F/g, Cacit and TMP were as effective as a gold standard one.

  18. Buffering action of human dentin in vitro.

    Science.gov (United States)

    Camps, J; Pashley, D H

    2000-01-01

    The purpose of this study was to determine the relative contributions of the mineral and organic phases of dentin to its total buffering capacity and to compare the buffering abilities of normal and caries-affected dentin for acids used in adhesive dentistry. Disks of normal and caries-affected human coronal dentin 0.6 mm thick were prepared. Fifty microL of various acids were applied to the surface of mineralized or completely demineralized dentin for varying lengths of time. They were collected from the surface and combined with water rinses to permit titration of the total amount of acid applied, the amount recovered, the total amount that was taken up by the dentin, and the amount that diffused across dentin into 1 mL of water. Equal volumes of acids were applied to mineralized or demineralized dentin powder or hydroxyapatite powder. About 88% to 90% of applied acid was recovered from the surface; only 10% to 12% of the acid was taken up by dentin. Of the H+ that was taken up, only 1% to 2% actually diffused across 0.6 mm of dentin. Increasing the application time of 37% phosphoric acid did not increase the amount of H+ that diffused across dentin. Increasing the concentration of phosphoric acid from 10% to 65% produced only slight increases in H+ diffusion across dentin. There was no difference in the buffering capacity of normal vs caries-affected dentin disks. Almost all of the buffering capacity of dentin is due to its mineral phase. The high buffering capacity of dentin and the high reactivity of H+ insure that little H+ diffuses through dentin more than 0.6 mm thick.

  19. Influence of pH and oxygen content of buffer solutions on the corrosion behaviour of metallic materials

    International Nuclear Information System (INIS)

    Wiedemann, K.H.

    1977-05-01

    The application of solutions to the decontamination of materials in nuclear installations is based on the condition that their corrosion behaviour is clearly understood. Since electrochemical corrosion is due to cathodic and anodic partial reactions which are influenced in different ways by the pH of the solution and the oxygen content it is suggested that the results of electrochemical experiments with buffer solutions be used as a model for predicting the corrosion behaviour of materials in other solutions. In the tests described here potentio-kinetic current-potential-curves have been traced and galvanic corrosion tests have been made. The results obtained in ascorbic acid, potassium hydrogen phthalate, ammonium citrate and acetate, sodium and potassium tartrate, ammonium hydrogen phosphate, sodium carbonate, hexamethylene tetramin, ethylene diamine enable - on the basis of summarized current-potential-curves - the metals studied to be classified in four groups characterized by clear differences concerning the influence of pH on the corrosion behaviour. (Auth.)

  20. Laboratory studies into the use of the scandium-46-EDTA complex as a tracer for groundwater flow

    International Nuclear Information System (INIS)

    Cheng, H.; Nixon, S.C.

    1988-01-01

    Gamma ray emitting metal radionuclides, when complexed with an appropriate complexing agent, provide a wide choice of water tracers particularly for groundwater studies where a radionuclide of appropriate half-life suited to the particular study can be selected. Scandium-46 has easily detectable gamma emission and a suitable half-life (84 days) for medium term studies. It has been widely and successfully used as a tracer in studies of sediment movement but has not yet been introduced as a groundwater tracer. In our experiments the chemical aspects of the preparation of Sc-46-EDTA were studied in some detail and its behaviour in various mineralogical environments was evaluated with reference to the standard tracer, tritiated water. The experimental results have shown that the scandium cation can be easily complexed with EDTA to form soluble SC-EDTA. The complex is very stable in a wide range of pH; the adsorptive properties of Sc-EDTA in the batch studies and the retardation and recovery in the column tests in comparison with tritiated water are quite satisfactory. In general Sc-46-EDTA is a promising tracer for groundwater studies. In the report the appropriate conditions, procedures and some rational and efficient methods for testing the purity of Sc-46-EDTA in the preparation of the tracer solution of Sc-46-EDTA are described. In addition, it has been found that the formation of the metal hydroxide colloids is the major reason for the great loss in groundwater aquifers of most trivalent metal nuclide tracers in the cationic form including scandium-46. (author). 29 refs, 11 figs, 12 tabs

  1. The status of phosphorus in Thai soils and P evaluation using EDTA-NaF extraction method

    Directory of Open Access Journals (Sweden)

    Toru Matoh

    2003-07-01

    Full Text Available Although the available P extracted by Bray II method in tropical soil is low, most of tropical plants can grow well. The objective of this study was to study P status and to evaluate the available P extracted by EDTA-NaF method. Top soil and sub soil of 10 dominant soil series in Thailand were analyzed for some chemical properties and characterization of the forms of phosphorus using EDTA-NaF extraction and successive phosphorus extraction by the modified Sekiya method. The soil total P concentration was 38-1137 mg P2O5 kg-1. The available Bray II-P was very low to high (1-76 mg P2O5 kg-1, and it approximated 0.17-12% of the total P. Iron and aluminum phosphates were the main fraction of inorganic P in acid soil, whereas Ca phosphates were in calcareous soils. Organic P content accounted for 33-67% and most of them were bound with Fe and Al in acid soils and Ca in calcareous soils. P extracted by EDTA-NaF reagent was obviously larger than that of Bray II reagent. The EDTA-NaF extracted P [high molecular weight organic P (HMWP+ inorganic P (EDTA ext Pi] was 7-46% and 1-6% of total P in acid soils and calcareous soils respectively. The EDTA ext Pi tended to be larger than HMWP except in Tk soil. The total amount of extracted P correlated well with Al-Pi and Fe-Pi which were the main fraction of inorganic P. It also correlated with HMWP, but HMWP did not correlate with organic P determine by ignition method and Ca-Po, Fe-Po and Al-Po. The EDTA-NaF method may be suitable for P evaluation in the soils which have high amounts of Fe-Pi, Al -Pi and organic P widely distributed in Thailand.

  2. Decomplexation efficiency and mechanism of Cu(II)-EDTA by H2O2 coupled internal micro-electrolysis process.

    Science.gov (United States)

    Zhou, Dongfang; Hu, Yongyou; Guo, Qian; Yuan, Weiguang; Deng, Jiefan; Dang, Yapan

    2016-12-29

    Internal micro-electrolysis (IE) coupled with Fenton oxidation (IEF) was a very effective technology for copper (Cu)-ethylenediaminetetraacetic acid (EDTA) wastewater treatment. However, the mechanisms of Cu 2+ removal and EDTA degradation were scarce and lack persuasion in the IEF process. In this paper, the decomplexation and removal efficiency of Cu-EDTA and the corresponding mechanisms during the IEF process were investigated by batch test. An empirical equation and the oxidation reduction potential (ORP) index were proposed to flexibly control IE and the Fenton process, respectively. The results showed that Cu 2+ , total organic carbon (TOC), and EDTA removal efficiencies were 99.6, 80.3, and 83.4%, respectively, under the proper operation conditions of iron dosage of 30 g/L, Fe/C of 3/1, initial pH of 3.0, Fe 2+ /H 2 O 2 molar ratio of 1/4, and reaction time of 20 min, respectively for IE and the Fenton process. The contributions of IE and Fenton to Cu 2+ removal were 91.2 and 8.4%, respectively, and those to TOC and EDTA removal were 23.3, 25.1, and 57, 58.3%, respectively. It was found that Fe 2+ -based replacement-precipitation and hydroxyl radical (•OH) were the most important effects during the IEF process. •OH played an important role in the degradation of EDTA, whose yield and productive rate were 3.13 mg/L and 0.157 mg/(L min -1 ), respectively. Based on the intermediates detected by GC-MS, including acetic acid, propionic acid, pentanoic acid, amino acetic acid, 3-(diethylamino)-1,2-propanediol, and nitrilotriacetic acid (NTA), a possible degradation pathway of Cu-EDTA in the IEF process was proposed. Graphical abstract The mechanism diagram of IEF process.

  3. Smear layer removal capacity of disinfectant solutions used with and without EDTA for the irrigation of canals: a SEM study

    Directory of Open Access Journals (Sweden)

    Menezes Ana Carolina Silveira Cardoso de

    2003-01-01

    Full Text Available The purpose of this study was to carry out a scanning electron microscopic (SEM analysis of the cleaning qualities and smear layer removal from root canal walls, instrumented and irrigated with 2.5% NaOCl, 2.0% chlorhexidine and saline solutions. Fifty extracted teeth were used in this study. All teeth were radiographed to determine the existence of a single canal. The crowns were cut at the cervical limit and the root canals were instrumented with K-type files up to size 45. During root canal preparation, irrigations were made with the different solutions being evaluated: Group 1: 2.5% NaOCl (10 roots; Group 2: 2.5% NaOCl and 17% EDTA for 2 minute (10 roots; Group 3: 2.0% chlorhexidine (10 roots; Group 4: 2.0% chlorhexidine and 17% EDTA for 2 minutes (10 roots; Group 5: saline solution (5 roots; Group 6: saline solution and 17% EDTA for 2 minutes (5 roots. After instrumentation, the canals were irrigated with each one of the solutions and the roots were cut in the buccolingual direction for SEM analysis, at the cervical, middle and apical thirds, to ascertain the presence or absence of smear layer and debris. SEM analysis was performed by three calibrated examiners and scores were submitted to Kruskal-Wallis test at the significance level of p = 5%. Results showed that the use of 17% EDTA decreased the smear layer significantly (p < 0.05 for all evaluated solutions in all thirds. When EDTA was not used, a significantly higher quantity of smear layer on the apical third was observed only in the NaOCl groups. The use of 17% EDTA was significant for debris removal except for the chlorhexidine groups. The following conclusion could be drawn: the use of 17% EDTA was necessary to enhance cleanness of the root canals.

  4. A COMPARISON OF CLOMIPHENE CITRATE AND SEQUENTIAL CLOMIPHENE CITRATE PLUS HUMAN MENOPAUSAL GONADOTROPIN FOR USE IN CONJUNCTION WITH INTRAUTERINE INSEMINATION

    Directory of Open Access Journals (Sweden)

    B. H. Rashidi

    2005-06-01

    Full Text Available There are currently ‎many different protocols in use for controlled ovarian hyperstimulation (COH, but the optimal method has ‎not yet been determined. To compare the outcome of COH using ‎clomiphene citrate (CC versus CC plus human menopausal gonadotropin (hMG in conjunction with intrauterine insemination (IUI, we studied 117 infertile couples‎. IUI with CC was used in 92 cycles ‎(group A and IUI with CC plus hMG was used in 66 cycles (group B. ‎Data analysis demonstrated no significant difference between the two ‎groups with respect to patients’ age, duration and type of infertility, prior COH and endometrial thickness and pattern. Group A had a little ‎longer follicular phase length than group B. ‎Pregnancy rate for group A and B were 6.52% and 12.12%, respectively (P= 0.22. ‎Endometrial pattern and thickness had no impact on pregnancy rate. ‎There were no multiple gestation and obvious hyperstimulation syndrome. ‎For patients undergoing controlled ovarian hyperstimulation with IUI, ‎CC plus hMG protocol yields higher pregnancy rate than one using CC, although this ‎difference was not statistically significant because of limitation of number of ‎cycles.

  5. Application of EDTA decontamination on soils affected by mining activities and impact of treatment on the geochemical partition of metal contaminants.

    Science.gov (United States)

    Xia, Wenbin; Gao, Hui; Wang, Xianhai; Zhou, Chunhua; Liu, Yunguo; Fan, Ting; Wang, Xin

    2009-05-30

    Two soil samples were collected at mining areas located in southern Hunan Province, China. EDTA extraction of Pb, Zn, Cu and Cd from these two tailing soils was studied using column leaching experiments. The redistributions of heavy metals (HMs) were determined using the modified BCR (Community Bureau of Reference) sequential extraction procedure, before and after EDTA extraction. The results indicated that EDTA was an effective extractant because of its strong chelating ability for various HMs. The proportions of Pb, Zn, Cu and Cd in the four fractions varied largely after EDTA extraction. The extraction efficiency of EDTA of the acid-extractable fraction (AEX) was significant in shallow soil column, while in deeper soil column, decrease of the extraction efficiency of reduced (RED), oxidizable (OX) and residual fractions (RES) was obtained, which was mainly due to the decrease of EDTA concentration.

  6. Health-related quality of life in women with newly diagnosed polycystic ovary syndrome randomized between clomifene citrate plus metformin or clomifene citrate plus placebo

    NARCIS (Netherlands)

    Moll, E.; van Wely, M.; Lambalk, C. B.; Bossuyt, P. M. M.; van der Veen, F.

    2012-01-01

    What is the health-related quality of life (HRQoL) in women with polycystic ovary syndrome (PCOS) undergoing ovulation induction with clomifene citrate (CC) combined with metformin compared with those using CC combined with placebo? Overall quality of life in women with PCOS treated with CC plus

  7. Health-related quality of life in women with newly diagnosed polycystic ovary syndrome randomized between clomifene citrate plus metformin or clomifene citrate plus placebo

    NARCIS (Netherlands)

    Moll, E.; van Wely, M.; Lambalk, C.B.; Bossuyt, P.M.M.; van der Veen, F.

    2012-01-01

    Study Question What is the health-related quality of life (HRQoL) in women with polycystic ovary syndrome (PCOS) undergoing ovulation induction with clomifene citrate (CC) combined with metformin compared with those using CC combined with placebo? Summary Answer Overall quality of life in women with

  8. Whole-body retention studies of /sup 167/Tm--citrate. Estimation of radiation dose to humans from /sup 167/Tm--citrate

    Energy Technology Data Exchange (ETDEWEB)

    Hiraki, T; Ando, A [Kanazawa Univ. (Japan). School of Paramedicine; Mori, H; Ando, I; Sakamoto, K

    1978-02-01

    For the purpose of calculating absorbed dose to humans from /sup 167/Tm-citrate, the whole-body retention studies using 5 rats were carried out. Up to 40 days following intravenous injection of /sup 167/Tm-citrate, the whole-body counts were monitored with an animal counter. The whole-body retention curve was obtained with three exponential components. Namely, the 26% of the injected /sup 167/Tm-citrate had a biological half-time of 3.4 hours, 12.5% had a biological half-time of 99 hours and 61.5% had a biological half-time of 106 days. These results indicate, that three components consist of the rapid clearance from the kidneys, the retention in the liver and other soft tissues with relatively long half-time and the retention in the bones with long half-time. Based on these biological data and the MIRD Committee method, the average dose estimates to the bone and whole-body from intravenous administration of 1 mCi /sup 167/Tm-citrate were 7.08 rads and 1.28 rads, respectively.

  9. Basal buffer systems for a newly glycosylated recombinant human interferon-β with biophysical stability and DoE approaches.

    Science.gov (United States)

    Kim, Nam Ah; Song, Kyoung; Lim, Dae Gon; Hada, Shavron; Shin, Young Kee; Shin, Sangmun; Jeong, Seong Hoon

    2015-10-12

    The purpose of this study was to develop a basal buffer system for a biobetter version of recombinant human interferon-β 1a (rhIFN-β 1a), termed R27T, to optimize its biophysical stability. The protein was pre-screened in solution as a function of pH (2-11) using differential scanning calorimetry (DSC) and dynamic light scattering (DLS). According to the result, its experimental pI and optimal pH range were 5.8 and 3.6-4.4, respectively. Design of experiment (DoE) approach was developed as a practical tool to aid formulation studies as a function of pH (2.9-5.7), buffer (phosphate, acetate, citrate, and histidine), and buffer concentration (20 mM and 50 mM). This method employed a weight-based procedure to interpret complex data sets and to investigate critical key factors representing protein stability. The factors used were Tm, enthalpy, and relative helix contents which were obtained by DSC and Fourier Transform Infrared spectroscopy (FT-IR). Although the weights changed by three responses, objective functions from a set of experimental designs based on four buffers were highest in 20 mM acetate buffer at pH 3.6 among all 19 scenarios tested. Size exclusion chromatography (SEC) was adopted to investigate accelerated storage stability in order to optimize the pH value with susceptible stability since the low pH was not patient-compliant. Interestingly, relative helix contents and storage stability (monomer remaining) increased with pH and was the highest at pH 4.0. On the other hand, relative helix contents and thermodynamic stability decreased at pH 4.2 and 4.4, suggesting protein aggregation issues. Therefore, the optimized basal buffer system for the novel biobetter was proposed to be 20 mM acetate buffer at pH 3.8±0.2. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. Restricted diffusion of CrEDTA and cyanocobalamine across the exchange vessels in rat hindquarters.

    Science.gov (United States)

    Haraldsson, B; Rippe, B

    1986-07-01

    The degree of diffusional restriction of skeletal muscle capillary walls to small solutes was estimated from the permeability surface area products (PS) of CrEDTA (MW = 341) and cyanocobalamine (MW = 1355), using computerized 'on-line' recordings of venous single injection indicator dilution curves. Experiments were performed on isolated perfused maximally vasodilated rat hindquarters during largely isogravimetric conditions and the arrangements allowed for measurements of capillary filtration coefficients (CFC). Extraction of tracer varied markedly as a function of transit time and, furthermore, PS increased with increasing flows, both these phenomena indicating tissue and flow heterogeneity. At maximal flows the disturbing influence of heterogeneity will be minimal and hence the diffusion capacities obtained by extrapolating PS area to infinite flows, so called PS tot values, were considered to give the best estimation of the 'true' capillary diffusion capacities. The value of PS tot was 12.9 +/- 0.5 for CrEDTA and 5.1 +/- 0.3 ml min-1 per 100 g for vitamin B12. The calculated PS tot ratio of 2.59 +/- 0.11 indicates restricted diffusion through equivalent pores of radius 53 A, whereas the ratio of the free diffusion coefficients for these solutes is 1.79. Using PS peak for the calculations (totally neglecting heterogeneity) the pore radius was, however, markedly overestimated. Thus, for a PS-ratio of 1.89 +/- 0.04 for CrEDTA vs. B12 an equivalent pore radius of 300 A was calculated. Also, using PS area (only partly correcting for heterogeneity) overestimated the pore radius (70 A) from a mean PS-ratio of 2.33 +/- 0.05. It was concluded that the equivalent pore radius in rat hindquarter microvascular walls is 53 A or even smaller in essential agreement with data from osmotic transient experiments in the same preparation (r approximately 40 A).

  11. Small bowel permeability to 51Cr-EDTA in children with recurrent abdominal pain

    International Nuclear Information System (INIS)

    Meer, S.B. van der.; Forget, P.P.

    1990-01-01

    Small bowel permeability was investigated in 87 children with recurrent abdominal pain by measuring the 24-h urinary excretion of orally administered 51 Cr-EDTA. The mean excreation was 3.64% ± 1.49% per 24 h. The difference between the mean urinary excretion in children with recurrent abdominal pain and control children (2.51% ± 0.70%), was significant (p<0.01, two sample t-test). The increased small permeability in children with recurrent abdominal pain might indicate an intestinal etiology for the patients complaints

  12. Positron emission tomography with 68Ga-EDTA in the diagnosis and localization of CSF fistulas

    International Nuclear Information System (INIS)

    Bergstrand, G.; Bergstroem, M.; Eriksson, L.; Edner, G.; Widen, L.

    1982-01-01

    Five patients with cerebrospinal fluid (CSF) rhinorrhea were investigated with computed tomography (CT) and positron emission tomography (PET) to localize the site of a CSF fistula. After intrathecal injection of 10 MBq of 68 Ga-EDTA, radioactivity was demonstrated in the basal cisterns. In three cases, the site of the fistula was visualized with PET. It is not always possible to demonstrate a CSF leakage with CT cisternography (CTC) using metrizamide, particularly in cases with minute fistulas or intermittent CSF rhinorrhea. With further experience and improved PET techniques, it may be possible to detect even very small fistulas

  13. Role of CA-EDTA on the Synthesizing Process of Cerate-Zirconate Ceramics Electrolyte

    OpenAIRE

    Abdullah, Nur Athirah; Hasan, Sharizal; Osman, Nafisah

    2013-01-01

    The role of a combination between citric acid (CA) and ethylenediaminetetra acetic acid (EDTA) as chelating agents in preparation of BaCe0.54Zr0.36Y0.1O2.95 powder by a modified sol-gel method is reported. The precursor solutions were prepared from metal nitrate salts (M+), chelating agents (C), and ethylene glycol (EG) at molar ratio of M+ : C : EG = 3 : 2 : 3. Chemical and phase transformation of samples during thermal decomposition were analyzed by thermogravimetric analysis (TGA) and Four...

  14. The effect of CaNa{sub 2}EDTA on excretion of {sup 210}PB, {sup 210}Po and stable lead in cases of chronic lead intoxication

    Energy Technology Data Exchange (ETDEWEB)

    Knezevic, I.; Milacic, S.; Novak, Lj.; Uzelac, V.; Nesic, V

    1998-07-01

    The study describes the effect of CaNa{sub 2}EDTA on the excretion of the naturally occurring radionuclides {sup 210}Pb, {sup 210}Po and stable lead in workers' urine. The CaNa{sub 2}EDTA was administered intravenously to workers in the morning for five days. The results show that CaNa{sub 2}EDTA mobilises biologically active {sup 210}Pb, {sup 210}Po and stable lead, appreciably increasing their concentration in urine. (author)

  15. Coupled microrings data buffer using fast light

    Science.gov (United States)

    Scheuer, Jacob; Shahriar, Selim

    2013-03-01

    We present a theoretical study of a trap-door optical buffer based on a coupled microrings add/drop filter (ADF) utilizing the white light cavity (WLC). The buffer "trap-door" can be opened and closed by tuning the resonances of the microrings comprising the ADF and trap/release optical pulses. We show that the WLC based ADF yields a maximally flat filter which exhibits superior performances in terms of bandwidth and flatness compared to previous design approaches. We also present a realistic, Silicon-over-Insulator based, design and performance analysis taking into consideration the realistic properties and limitations of the materials and the fabrication process, leading to delays exceeding 850ps for 80GHz bandwidth, and a corresponding delay-bandwidth product of approximately 70.

  16. MOISTURE-BUFFERING CHARACTERISTICS OF BUILDING MATERIALS

    Directory of Open Access Journals (Sweden)

    Young Cheol Choi

    2016-05-01

    Full Text Available The humidity level of indoor air is an important factor influencing the air quality and energy consumption of buildings, as well as the durability of building components. Indoor humidity levels depend on several factors, such as moisture sources, air flow, and the adsorption/desorption properties of materials. The moisture-buffering characteristics of building materials that are in contact with indoor air may help moderate the variations of indoor humidity, especially in the summer and winter. In this study, the moisture adsorption/desorption properties of building materials were investigated experimentally and numerically. These properties can be used to characterize the ability of building materials to exchange moisture with the indoor environment. This study indicates that a building material surface resistivity was the main factor creating variations of moisture buffering.

  17. Chemical buffering capacity of clay rock

    International Nuclear Information System (INIS)

    Beaucaire, C.; Pearson, F.J.; Gautschi, A.

    2004-01-01

    The long-term performance of a nuclear waste repository is strongly dependent on the chemical properties of the host rock. The host rock establishes the chemical environment that determines such important performance attributes as radionuclide solubilities from the waste and the transport rates from the repository to the accessible environment. Clay-rich rocks are especially favourable host rocks because they provide a strong buffering capacity to resist chemical changes prompted either internally, by reactions of the waste itself and emplacement materials, or externally, by changes in the hydrologic systems surrounding the host rock. This paper will focus on three aspects of the stability of clay-rich host rocks: their ability to provide pCO 2 and redox buffering, and to resist chemical changes imposed by changes in regional hydrology and hydro-chemistry. (authors)

  18. Effects and mechanisms of action of sildenafil citrate in human chorionic arteries

    Directory of Open Access Journals (Sweden)

    Lynch Tadhg

    2009-04-01

    Full Text Available Abstract Objectives Sildenafil citrate, a specific phosphodiesterase-5 inhibitor, is increasingly used for pulmonary hypertension in pregnancy. Sildenafil is also emerging as a potential candidate for the treatment of intra-uterine growth retardation and for premature labor. Its effects in the feto-placental circulation are not known. Our objectives were to determine whether phosphodiesterase-5 is present in the human feto-placental circulation, and to characterize the effects and mechanisms of action of sildenafil citrate in this circulation. Study Design Ex vivo human chorionic plate arterial rings were used in all experiments. The presence of phosphodiesterase-5 in the feto-placental circulation was determined by western blotting and immunohistochemical staining. In a subsequent series of pharmacologic studies, the effects of sildenafil citrate in pre-constricted chorionic plate arterial rings were determined. Additional studies examined the role of cGMP and nitric oxide in mediating the effects of sildenafil. Results Phosphodiesterase-5 mRNA and protein was demonstrated in human chorionic plate arteries. Immunohistochemistry demonstrated phosphodiesterase-5 within the arterial muscle layer. Sildenafil citrate produced dose dependent vasodilatation at concentrations at and greater than 10 nM. Both the direct cGMP inhibitor methylene blue and the cGMP-dependent protein kinase inhibitor Rp-8-Br-PET-cGMPS significantly attenuated the vasodilation produced by sildenafil citrate. Inhibition of NO production with L-NAME did not attenuate the vasodilator effects of sildenafil. In contrast, sildenafil citrate significantly enhanced the vasodilation produced by the NO donor sodium nitroprusside. Conclusion Phosphodiesterase-5 is present in the feto-placental circulation. Sildenafil citrate vasodilates the feto-placental circulation via a cGMP dependent mechanism involving increased responsiveness to NO.

  19. Effects and mechanisms of action of sildenafil citrate in human chorionic arteries.

    LENUS (Irish Health Repository)

    Maharaj, Chrisen H

    2009-01-01

    OBJECTIVES: Sildenafil citrate, a specific phosphodiesterase-5 inhibitor, is increasingly used for pulmonary hypertension in pregnancy. Sildenafil is also emerging as a potential candidate for the treatment of intra-uterine growth retardation and for premature labor. Its effects in the feto-placental circulation are not known. Our objectives were to determine whether phosphodiesterase-5 is present in the human feto-placental circulation, and to characterize the effects and mechanisms of action of sildenafil citrate in this circulation. STUDY DESIGN: Ex vivo human chorionic plate arterial rings were used in all experiments. The presence of phosphodiesterase-5 in the feto-placental circulation was determined by western blotting and immunohistochemical staining. In a subsequent series of pharmacologic studies, the effects of sildenafil citrate in pre-constricted chorionic plate arterial rings were determined. Additional studies examined the role of cGMP and nitric oxide in mediating the effects of sildenafil. RESULTS: Phosphodiesterase-5 mRNA and protein was demonstrated in human chorionic plate arteries. Immunohistochemistry demonstrated phosphodiesterase-5 within the arterial muscle layer. Sildenafil citrate produced dose dependent vasodilatation at concentrations at and greater than 10 nM. Both the direct cGMP inhibitor methylene blue and the cGMP-dependent protein kinase inhibitor Rp-8-Br-PET-cGMPS significantly attenuated the vasodilation produced by sildenafil citrate. Inhibition of NO production with L-NAME did not attenuate the vasodilator effects of sildenafil. In contrast, sildenafil citrate significantly enhanced the vasodilation produced by the NO donor sodium nitroprusside. CONCLUSION: Phosphodiesterase-5 is present in the feto-placental circulation. Sildenafil citrate vasodilates the feto-placental circulation via a cGMP dependent mechanism involving increased responsiveness to NO.

  20. The effect of sildenafil citrate (Viagra) on visual sensitivity.

    Science.gov (United States)

    Stockman, Andrew; Sharpe, Lindsay T; Tufail, Adnan; Kell, Philip D; Ripamonti, Caterina; Jeffery, Glen

    2007-06-08

    The erectile dysfunction medicine sildenafil citrate (Viagra) inhibits phosphodiesterase type 6 (PDE6), an essential enzyme involved in the activation and modulation of the phototransduction cascade. Although Viagra might thus be expected to impair visual performance, reports of deficits following its ingestion have so far been largely inconclusive or anecdotal. Here, we adopt tests sensitive to the slowing of the visual response likely to result from the inhibition of PDE6. We measured temporal acuity (critical fusion frequency) and modulation sensitivity in four subjects before and after the ingestion of a 100-mg dose of Viagra under conditions chosen to isolate the responses of either their short-wavelength-sensitive (S-) cone photoreceptors or their long- and middle-wavelength-sensitive (L- and M-) cones. When vision was mediated by S-cones, all subjects exhibited some statistically significant losses in sensitivity, which varied from mild to moderate. The two individuals who showed the largest S-cone sensitivity losses also showed comparable losses when their vision was mediated by the L- and M-cones. Some of the losses appear to increase with frequency, which is broadly consistent with Viagra interfering with the ability of PDE6 to shorten the time over which the visual system integrates signals as the light level increases. However, others appear to represent a roughly frequency-independent attenuation of the visual signal, which might also be consistent with Viagra lengthening the integration time (because it has the effect of increasing the effectiveness of steady background lights), but such changes are also open to other interpretations. Even for the more affected observers, however, Viagra is unlikely to impair common visual tasks, except under conditions of reduced visibility when objects are already near visual threshold.