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Sample records for citrate precursor method

  1. 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.

  2. Influence of Y and La substitution on particle size, structural and magnetic properties of nanosized nickel ferrite prepared by using citrate precursor method

    Energy Technology Data Exchange (ETDEWEB)

    Anh, Luong Ngoc [International Training Institute for Materials Science (ITIMS), Hanoi University of Science and Technology, 1 Dai Co Viet Road, Hanoi (Viet Nam); Loan, To Thanh, E-mail: totloan@itims.edu.vn [International Training Institute for Materials Science (ITIMS), Hanoi University of Science and Technology, 1 Dai Co Viet Road, Hanoi (Viet Nam); Duong, Nguyen Phuc [International Training Institute for Materials Science (ITIMS), Hanoi University of Science and Technology, 1 Dai Co Viet Road, Hanoi (Viet Nam); Vietnam-Japan International Institute for Science of Technology (VJIIST), Hanoi University of Science and Technology, 1 Dai Co Viet Road, Hanoi (Viet Nam); Soontaranon, Siriwat [Synchrotron Light Research Institute, 111 University Avenue, Suranaree, Muang, Nakhon Ratchasima 30000 (Thailand); Viet Nga, Tran Thi; Hien, Than Duc [International Training Institute for Materials Science (ITIMS), Hanoi University of Science and Technology, 1 Dai Co Viet Road, Hanoi (Viet Nam)

    2015-10-25

    The compounds with the formulas NiFe{sub 2}O{sub 4}, NiFe{sub 1.9}Y{sub 0.1}O{sub 4} and NiFe{sub 1.9}La{sub 0.1}O{sub 4} were prepared by citrate precursor method and followed by heat treatment in air at 600 °C for 5 h. Crystal structure, valence state, chemical bonding and composition of the samples were studied rigorously by XRD, SXRD, XANES, FTIR and ICP–AES. Rietveld refinement of XRD and SXRD patterns reveals that the samples crystallize in single spinel phase with almost inverted structure in which the substituted ions Y{sup 3+} and La{sup 3+} locate in the octahedral sites and about ten percents of nickel atoms were found at the tetrahedral sites. Morphology and particle size were studied by SEM and TEM. The results show that the samples are composed of clustered nanoparticles with mean particle size decreases approximately from 20 nm in NiFe{sub 2}O{sub 4} sample to 10 nm in the substituted ones. The magnetic measurements were carried out by means of a VSM. Spontaneous magnetization, magnetic coercivity, Curie temperature, superparamagnetic transition temperature, interparticle interaction energy and effective anisotropy were determined and explained on the basis of the surface and finite–size effects and cation distribution. - Highlights: • Y{sup 3+} and La{sup 3+} substituted NiFe{sub 2}O{sub 4} nanoparticles are synthesized by citrate precursor method involving less energy. • XRD, SXRD and FTIR spectra reveal the crystallographic site occupancy of Y{sup 3+} and La{sup 3+}. • Compositions and valence states of cations are verified by ICP-AES and XANES. • Y{sup 3+} and La{sup 3+} substitution decreases the mean particle size to about 10 nm. • Influence of rare earth substitution and finite size in magnetic properties are investigated.

  3. 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...

  4. Electromagnetic attenuation analysis of Ni{sub 0.4}Zn{sub 0.6}Fe{sub 2O4} obtained by citrate precursor method; Analise da atenuacao de radiacao eletromagnetica de Ni{sub 0.4}Zn{sub 0.6}Fe{sub 2O4} obtido pelo metodo de citrato precursor

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, K. [Centro Tecnico Aeroespacial (CTA-IAE), Sao Jose dos Campos, SP (Brazil). Inst. de Atividades Espaciais. Div. Materiais; Moura, A.E.G.; Nasar, R.S.; Nasar, M.C. [Universidade Federal do Rio Grande do Norte (UFRN), Natal (Brazil). Dept. de Quimica; Pereira, J.J. [Universidade de Taubate, SP (Brazil)

    2010-07-01

    In this work, two types of synthesized Ni{sub 0,4}Zn{sub 0,6}Fe{sub 2}O{sub 4} by citrate precursor method. The first type was calcined at 350 deg C for 3.5 h, and the second, after calcination, it was subjected to heat treatment at 600 deg C for 2h in argon atmosphere. Both types were analyzed by X-ray diffraction (XRD) and equipment waveguide. The data were investigated by Rietveld refinement method and showed the NiZn ferrite phase with crystallite size of 12.2 +- 0.1 nm (350 deg C) and 166.7 +- 3.6 nm (600 deg C). The heat treatment also influenced the values of electric permittivity and magnetic permeability, and attenuation of electromagnetic radiation in the frequency range in microwave (8-12 GHz). The sample treated attenuates more and allows its application with thinner, making it attractive its use as absorber material in this frequency range. (author)

  5. Structural and magnetic properties of Ni-Zn doped BaM nanocomposite via citrate precursor

    Energy Technology Data Exchange (ETDEWEB)

    Rana, Kush; Thakur, Preeti; Thakur, Atul, E-mail: atulphysics@gmail.com [School of Physics and Materials Science, Shoolini University, Solan, India 173212 (India); Tomar, Monika; Gupta, Vinay [Department of Physics and Astrophysics, University of Delhi, Delhi, India 110007 (India)

    2016-05-23

    Ni-Zn substituted M-type barium ferrite nanocomposite has been prepared via citrate precursor method. Nanocomposite having composition BaNi{sub 0.5}Zn{sub 0.5}Fe{sub 11}O{sub 19} was sintered at 900°C for 3hrs and characterized by using different characterization techniques. X-ray diffraction (XRD) confirmed the formation of double phase with most prominent peak at (114). Average crystallite size for pure BaM and BNZFO were found to be 36 nm & 45 nm. Field emission scanning electron microscopy (FESEM) confirmed the formation of hexagonal platelets with a layered structure. Magnetic properties of these samples were investigated by using vibrating sample magnetometer (VSM). Magnetic parameters like saturation magnetization (M{sub s}), coericivity (H{sub c}) and squareness ratio (SQR) of nanocomposite were found to be 60 emu/g, 3663 Oe and 0.6163 respectively. These values were noticed to be higher as compared to pure BaM. Enhanced magnetic properties of nanocomposite were strongly dependent on exchange coupling. Therefore these properties make this nanocomposite a suitable candidate for magnetic recording and high frequency applications.

  6. Structural and magnetic properties of Ni-Zn doped BaM nanocomposite via citrate precursor

    International Nuclear Information System (INIS)

    Rana, Kush; Thakur, Preeti; Thakur, Atul; Tomar, Monika; Gupta, Vinay

    2016-01-01

    Ni-Zn substituted M-type barium ferrite nanocomposite has been prepared via citrate precursor method. Nanocomposite having composition BaNi_0_._5Zn_0_._5Fe_1_1O_1_9 was sintered at 900°C for 3hrs and characterized by using different characterization techniques. X-ray diffraction (XRD) confirmed the formation of double phase with most prominent peak at (114). Average crystallite size for pure BaM and BNZFO were found to be 36 nm & 45 nm. Field emission scanning electron microscopy (FESEM) confirmed the formation of hexagonal platelets with a layered structure. Magnetic properties of these samples were investigated by using vibrating sample magnetometer (VSM). Magnetic parameters like saturation magnetization (M_s), coericivity (H_c) and squareness ratio (SQR) of nanocomposite were found to be 60 emu/g, 3663 Oe and 0.6163 respectively. These values were noticed to be higher as compared to pure BaM. Enhanced magnetic properties of nanocomposite were strongly dependent on exchange coupling. Therefore these properties make this nanocomposite a suitable candidate for magnetic recording and high frequency applications.

  7. Niobium-aluminum oxynitride prepared by ammonolysis of oxide precursor obtained through the citrate route

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, Shinichi; Ohashi, Yoshio; Masubuchi, Yuji; Takeda, Takashi; Motohashi, Teruki [Graduate School of Engineering, Hokkaido University, N13W8, Kita-ku, Sapporo 060-8628 (Japan); Kikkawa, Shinichi, E-mail: kikkawa@eng.hokudai.ac.j [Graduate School of Engineering, Hokkaido University, N13W8, Kita-ku, Sapporo 060-8628 (Japan)

    2009-08-12

    Oxynitrides in the (Nb{sub 1-x}Al{sub x})(O,N) quaternary system were prepared by ammonolysis of oxide precursor obtained through the citrate route. The products at 1000 deg. C were a mixture of Nb(N,O) and NbN{sub 0.95} at the niobium end (x = 0) and amorphous Al(O,N) at the aluminum end (x = 1). A new cubic compound (A) appeared mixed with Nb(N,O) in the compositional range 0.1 <= x <= 0.4. Its almost pure product was obtained at x = 0.5. The X-ray diffraction pattern was rock salt type (Nb{sub 0.56}Al{sub 0.44})(O{sub 0.38}N{sub 0.37}square{sub 025}) in F{sub m-3m} with a = 0.43481(1) nm. The product showed superconductivity with T{sub c} = 15 K. Its crystallinity was much improved and its superconducting volume fraction increased to 32% after its thermal annealing at 1100 deg. C in evacuated sealed tube. A second cubic compound (B), rock salt type Nb[(O,N){sub 0.85}square{sub 0.15}] with a = 0.434 nm, was observed mixed with amorphous Al(O,N) in the as-prepared products of the range 0.6 <= x <= 0.9.

  8. 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.

  9. Preparation of nanocrystalline Mg4Nb2O9 by citrate gel method

    Indian Academy of Sciences (India)

    Unknown

    using potassium niobate precursor. The purpose ... ficult to maintain reaction conditions. This citrate ... of metal ions by poly functional carboxyl acids such as citric acid or ... on a water bath at 100°C a gel was formed after evaporation of water.

  10. Citrate precursor synthesis, characterization and dielectric properties of Ba1-xSrxZrO3 (0 ≤ x ≤1)

    International Nuclear Information System (INIS)

    Ubaidullah, Mohd; Ahmad, Tokeer; Al-Hartomy, Omar A.

    2012-01-01

    Barium Strontium Zirconate (BSZ) nanoparticles of the general formula Ba 1-x Sr x ZrO 3 over the composition range of (x= 0.0, 0.05, 0.10, 0.15, 0.20, 0.25, 0.50, 0.75 and 1.0) have been successfully synthesized by simple and most elegant method known as Polymeric citrate precursor route using citric acid and ethylene glycol for the first time. These solid solutions were investigated by means of powder X-ray diffraction (PXRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM) and BET surface area studies. XRD studies revealed the monophasic nature of the powders after heating the precursor at 1000 ℃. The particle size obtained from TEM studies were found to be in the range of 13.8-40 nm. Specific surface area of the solid solutions comes out to be in the range of 49 to 94 m 2 g -1 . The average particle size of these nanoparticles could also be calculated using the equation: D BET = 6000/(ρ.S w ), where the symbols D BET , ρ, S w stand for average diameter of the spherical particle, theoretical density, and specific surface area of the sample in m 2 /g respectively

  11. Synthesis of In2O3nanoparticles by thermal decomposition of a citrate gel precursor

    International Nuclear Information System (INIS)

    Rey, J. F. Q.; Plivelic, T. S.; Rocha, R. A.; Tadokoro, S. K.; Torriani, I.; Muccillo, E. N. S.

    2005-01-01

    This paper describes the synthesis of indium oxide by a modified sol-gel method, and the study of thermal decomposition of the metal complex in air. The characterization of the intermediate as well as the final compounds was carried out by thermogravimetry, differential thermal analysis, Fourier transform infrared spectroscopy, X-ray diffraction, transmission electron microscopy, and small angle X-ray scattering. The results show that the indium complex decomposes to In 2 O 3 with the formation of an intermediate compound. Nanoparticles of cubic In 2 O 3 with crystallite sizes in the nanosize range were formed after calcination at temperatures up to 900 deg. C. Calcined materials are characterized by a polydisperse distribution of spherical particles with sharp and smooth surfaces

  12. Spin-on Bi4Sr3Ca3Cu4O16μ/sub x/ superconducting thin films from citrate precursors

    International Nuclear Information System (INIS)

    Furcone, S.L.; Chiang, Y.

    1988-01-01

    Thin films in the Bi-Sr-Ca-Cu-O system have been synthesized from homogeneous liquid citrate precursors by a spin-coating and pyrolysis method. Films prepared on SrTiO 3 substrates of [100] orientation show strongly textured orientations with the c axis of the predominant Bi 4 Sr 3 Ca 3 Cu 4 O 16 μ/sub x/ phase normal to the film plane. In a single coating and firing, crack-free films of 0.2--0.5 μm thickness are obtained. For films fired to peak temperatures of 850--875 0 C, linearly decreasing resistance with temperature is observed, with rho (300 K)∼460 μΩ cm and rho (300 K)rho (100 K)∼2.4. Clear onsets of superconductivity are observed at 90--100 K, with occasional films showing smaller resistant drops at 110--120 K. For all films, T/sub c/ (R = 0) occurs in the range 70--75 K. High critical current densities at 4.2 K of 5--8 x 10 5 Acm 2 are measured by direct transport

  13. German precursor study: methods and results

    International Nuclear Information System (INIS)

    Hoertner, H.; Frey, W.; von Linden, J.; Reichart, G.

    1985-01-01

    This study has been prepared by the GRS by contract of the Federal Minister of Interior. The purpose of the study is to show how the application of system-analytic tools and especially of probabilistic methods on the Licensee Event Reports (LERs) and on other operating experience can support a deeper understanding of the safety-related importance of the events reported in reactor operation, the identification of possible weak points, and further conclusions to be drawn from the events. Additionally, the study aimed at a comparison of its results for the severe core damage frequency with those of the German Risk Study as far as this is possible and useful. The German Precursor Study is a plant-specific study. The reference plant is Biblis NPP with its very similar Units A and B, whereby the latter was also the reference plant for the German Risk Study

  14. Silicon dioxide obtained by Polymeric Precursor Method

    International Nuclear Information System (INIS)

    Oliveira, C.T.; Granado, S.R.; Lopes, S.A.; Cavalheiro, A.A.

    2011-01-01

    The Polymeric Precursor Method is able for obtaining several oxide material types with high surface area even obtained in particle form. Several MO 2 oxide types such as titanium, silicon and zirconium ones can be obtained by this methodology. In this work, the synthesis of silicon oxide was monitored by thermal analysis, XRD and surface area analysis in order to demonstrate the influence of the several synthesis and calcining parameters. Surface area values as higher as 370m2/g and increasing in the micropore volume nm were obtained when the material was synthesized by using ethylene glycol as polymerizing agent. XRD analysis showed that the material is amorphous when calcinated at 600°C in despite of the time of calcining, but the material morphology is strongly influenced by the polymeric resin composition. Using Glycerol as polymerizing agent, the pore size increase and the surface area goes down with the increasing in decomposition time, when compared to ethylene glycol. (author)

  15. Tin dioxide nanostructured thin films obtained through polymeric precursor method

    Directory of Open Access Journals (Sweden)

    Marcelo Antônio Dal Santos

    2012-11-01

    Full Text Available Tin dioxide (SnO2 nanostructured thin films with low proportion of defects and low roughness were produced through the systematic control of temperature and viscosity of the precursor solutions used for thin films deposition. These solutions were obtained through the citrate method and the films were deposited through the ‘dip-coating’ technique on glass substrate and after thermal treatment at 470ºC/4h, they were characterized both structurally and morphologically through the X-ray diffractometry, optic microscopy, scanning electronic microscopy, atomic force microscopy, X-ray fluorescence, UV-Vis absorption spectroscopy and X-ray excited photoelectrons spectroscopy. The film thickness was obtained through scanning electronic microscopy of the films cross-section and correlated to the proportion of Sn and Si obtained through X-ray fluorescence. X-ray diffractometry of the films revealed the presence of peaks corresponding to the SnO2 crystalline phase, overlapping a wide peak between 20 and 30º (2?, characteristic of the glass substrate. Optic microscopy, Scanning electronic microscopy and atomic force microscopy revealed homogeneous films, with low roughness, suitable to several applications such as sensors and transparent electrodes. It could be observed through the UV-Vis absorption analysis that the films presented high optical transparency and ‘band gap’ energy 4.36 eV. The X-ray excited photoelectron spectroscopy confirmed the presence of SnO2, as well as traces of the elements present in the glass substrate and residual carbon from the thermal treatment of the films.

  16. Adsorption of citrate ions on hydroxyapatite synthesized by various methods

    International Nuclear Information System (INIS)

    Skwarek, E.; Janusz, W.; Sternik, D.

    2014-01-01

    The specific adsorption of citric acid ions at hydroxyapatite interface was investigated by the means of radioisotope method ( 14 C) as a function of citric acid ions concentration, NaCl concentration and pH. Application of the hydroxyapatite has become wide in the biomaterial field as the Ca 10 (OH) 2 (PO 4 ) 6 possess biocompatibility with human hard tissue. Hydroxyapatite was synthesized using three different methods. The physical properties of the resulting powder were characterized by DTA/TG, XRD, AFM and SEM microscopy. Physicochemical qualities characterizing the electrical double layer of the hydroxyapatite/NaCl solution interface were determined. The zeta potential and the adsorption of citric acid molecule were studied as a function of pH. The point of zero charge and the isoelectric point of samples were determined. Electrical double layer parameters of hydroxyapatite/NaCl interface are influenced by a synthesis method. The points pH pzc and pH IEP for sample 1 are pH pzc 7.5 and pH IEP 3; for sample 2 pH pzc 7.05 and pH IEP 3, for sample 3 pH pzc 6.7 and pH IEP 3. Temperature has weak influence both on pure substance and with citric acid adsorbed, as derivatographic analysis has shown, and characterization of hydroxyapatite structure may be carried out by this thermal analysis. Two phenomena are responsible for citric acid adsorption: phosphate group's replacement at hydroxyapatite surface by citric ions parallel to intraspherical complexes formation. (author)

  17. The stability and dielectric performance of BiNbO{sub 4} prepared by citrate method assisting sintering process

    Energy Technology Data Exchange (ETDEWEB)

    Zhai, Haifa [Henan Key Laboratory of Photovoltaic Materials, College of Physics and Electronic Engineering, Henan Normal University, Xinxiang, 453007 (China); National Laboratory of Solid State Microstructures, Nanjing University, Nanjing, 210093 (China); Chen, Bei; Luo, Hongying; Li, Haiqin; Zheng, Liuyang; Yang, Jien; Liu, Hairui; Liu, Zhiyong [Henan Key Laboratory of Photovoltaic Materials, College of Physics and Electronic Engineering, Henan Normal University, Xinxiang, 453007 (China)

    2016-09-15

    Low-temperature β phase BiNbO{sub 4} powders (denoted as Low-β) were prepared by a citrate method using home-made water-soluble niobium precursors. The stability of Low-β was systematically investigated from the aspects including calcination temperature, incubation time, and stress existing in pellets. Pure Low-β can be obtained between 700 and 750 C and the crystal evolution of Low-β has not completed yet, compared with high-temperature β phase. Low-β is kinetically stable and no phase transition occurs when increasing the incubation time below 750 C. Above 750 C, both the calcination temperature and incubation time can induce the abnormal phase transition from Low-β to α phase; also, stress existing in pellets can effectively activate the phase transition of Low-β. We can conclude that the Low-β is thermodynamically unstable, while in kinetics, Low-β is stable. The dielectric properties of BiNbO{sub 4} ceramics were investigated to analyze the influence of phase of BiNbO{sub 4} powders precursors, especially the effect of phase transition of Low-β. It's found that BiNbO{sub 4} powders firstly calcined at 700 C is the best precursor to prepare dense ceramics with uniform grain size and the dielectric permittivity and dielectric loss of BiNbO{sub 4} ceramics prepared at 1000 C is 56.6 and 0.001 at 10 kHz, respectively. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  18. CoFe2O4 nanocrystalline powders prepared by citrate-gel methods: Synthesis, structure and magnetic properties

    International Nuclear Information System (INIS)

    Cannas, C.; Falqui, A.; Musinu, A.; Peddis, D.; Piccaluga, G.

    2006-01-01

    Nanocrystalline CoFe 2 O 4 powders were prepared by decomposition of metal ion citrate precursors. Four samples were synthesized from precursor solutions having different pH values in the range 2 physisorption and Transmission Electron Microscopy. Magnetic properties were explored by a SQUID magnetometer. Three out of the four samples, coming from solutions of pH 2, 4 and 7, were produced by an autocombustion reaction and are very similar as regards average size of the nanoparticles (about 20 nm), their morphology and the magnetic properties, while the fourth sample was produced by a slower thermal decomposition and is composed of smaller nanoparticles (about 10 nm)

  19. Methods for forming particles from single source precursors

    Science.gov (United States)

    Fox, Robert V [Idaho Falls, ID; Rodriguez, Rene G [Pocatello, ID; Pak, Joshua [Pocatello, ID

    2011-08-23

    Single source precursors are subjected to carbon dioxide to form particles of material. The carbon dioxide may be in a supercritical state. Single source precursors also may be subjected to supercritical fluids other than supercritical carbon dioxide to form particles of material. The methods may be used to form nanoparticles. In some embodiments, the methods are used to form chalcopyrite materials. Devices such as, for example, semiconductor devices may be fabricated that include such particles. Methods of forming semiconductor devices include subjecting single source precursors to carbon dioxide to form particles of semiconductor material, and establishing electrical contact between the particles and an electrode.

  20. Bulk synthesis of nanocrystalline urania powders by citrate gel-combustion method

    Science.gov (United States)

    Sanjay Kumar, D.; Ananthasivan, K.; Venkata Krishnan, R.; Amirthapandian, S.; Dasgupta, Arup

    2016-01-01

    Bulk quantities (60 g) of nanocrystalline (nc) free flowing urania powders with crystallite size ranging from 38 to 252 nm have been synthesized for the first time by the citrate gel combustion method. A systematic study of the influence of the fuel (citric acid) to oxidant (nitrate) ratio (R) on the characteristics of the urania powders has been carried out for the first time. Mixture with an "R" value of 0.25 exhibited a vigorous auto-ignition reaction. This reaction was investigated with Differential Scanning Calorimetry (DSC) and in-situ thermogravimetry coupled with differential thermal analysis and mass spectrometry (TG-DTA-MS). The bulk density, specific surface area, X-ray crystallite size, residual carbon and size distribution of particles of this powder were unique. Microscopic and microstructural investigation of selected samples revealed the presence of nanocrystals with irregular exfoliated morphology; their Electron Energy Loss Spectra testified the covalency of the U-O bond.

  1. Bulk synthesis of nanocrystalline urania powders by citrate gel-combustion method

    International Nuclear Information System (INIS)

    Sanjay Kumar, D.; Ananthasivan, K.; Venkata Krishnan, R.; Amirthapandian, S.; Dasgupta, Arup

    2016-01-01

    Bulk quantities (60 g) of nanocrystalline (nc) free flowing urania powders with crystallite size ranging from 38 to 252 nm have been synthesized for the first time by the citrate gel combustion method. A systematic study of the influence of the fuel (citric acid) to oxidant (nitrate) ratio (R) on the characteristics of the urania powders has been carried out for the first time. Mixture with an “R” value of 0.25 exhibited a vigorous auto-ignition reaction. This reaction was investigated with Differential Scanning Calorimetry (DSC) and in-situ thermogravimetry coupled with differential thermal analysis and mass spectrometry (TG-DTA-MS). The bulk density, specific surface area, X-ray crystallite size, residual carbon and size distribution of particles of this powder were unique. Microscopic and microstructural investigation of selected samples revealed the presence of nanocrystals with irregular exfoliated morphology; their Electron Energy Loss Spectra testified the covalency of the U–O bond. - Highlights: • Bulk quantities of nanocrystalline urania were prepared for the first time using citrate gel combustion method. • Volume combustion was observed in mixtures with fuel to nitrate ratio (R) 0.25. • The value of R was found to significantly influence the characteristics of the final product. • Typical exfoliated microstructure and nanopores were observed. • Established correlation between particle size distribution and bulk density, X-ray crystallite size and lattice strain. • Relationship between fuel to nitrate (R) mole ratio and physical characteristics of powders were also established.

  2. Development of precursors recognition methods in vector signals

    Science.gov (United States)

    Kapralov, V. G.; Elagin, V. V.; Kaveeva, E. G.; Stankevich, L. A.; Dremin, M. M.; Krylov, S. V.; Borovov, A. E.; Harfush, H. A.; Sedov, K. S.

    2017-10-01

    Precursor recognition methods in vector signals of plasma diagnostics are presented. Their requirements and possible options for their development are considered. In particular, the variants of using symbolic regression for building a plasma disruption prediction system are discussed. The initial data preparation using correlation analysis and symbolic regression is discussed. Special attention is paid to the possibility of using algorithms in real time.

  3. Manganite perovskite ceramics, their precursors and methods for forming

    Science.gov (United States)

    Payne, David Alan; Clothier, Brent Allen

    2015-03-10

    Disclosed are a variety of ceramics having the formula Ln.sub.1-xM.sub.xMnO.sub.3, where 0.Itoreq.x.Itoreq.1 and where Ln is La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu or Y; M is Ca, Sr, Ba, Cd, or Pb; manganite precursors for preparing the ceramics; a method for preparing the precursors; and a method for transforming the precursors into uniform, defect-free ceramics having magnetoresistance properties. The manganite precursors contain a sol and are derived from the metal alkoxides: Ln(OR).sub.3, M(OR).sub.2 and Mn(OR).sub.2, where R is C.sub.2 to C.sub.6 alkyl or C.sub.3 to C.sub.9 alkoxyalkyl, or C.sub.6 to C.sub.9 aryl. The preferred ceramics are films prepared by a spin coating method and are particularly suited for incorporation into a device such as an integrated circuit device.

  4. Influence of concentration, time and method of application of citric acid and sodium citrate in root conditioning

    Science.gov (United States)

    CAVASSIM, Rodrigo; LEITE, Fábio Renato Manzolli; ZANDIM, Daniela Leal; DANTAS, Andrea Abi Rached; RACHED, Ricardo Samih Georges Abi; SAMPAIO, José Eduardo Cezar

    2012-01-01

    Objective The aim of this study was to establish the parameters of concentration, time and mode of application of citric acid and sodium citrate in relation to root conditioning. Material and Methods A total of 495 samples were obtained and equally distributed among 11 groups (5 for testing different concentrations of citric acid, 5 for testing different concentrations of sodium citrate and 1 control group). After laboratorial processing, the samples were analyzed under scanning electron microscopy. A previously calibrated and blind examiner evaluated micrographs of the samples. Non-parametric statistical analysis was performed to analyze the data obtained. Results Brushing 25% citric acid for 3 min, promoted greater exposure of collagen fibers in comparison with the brushing of 1% citric acid for 1 minute and its topical application at 1% for 3 min. Sodium citrate exposed collagen fibers in a few number of samples. Conclusion Despite the lack of statistical significance, better results for collagen exposure were obtained with brushing application of 25% citric acid for 3 min than with other application parameter. Sodium citrate produced a few number of samples with collagen exposure, so it is not indicated for root conditioning. PMID:22858707

  5. Influence of concentration, time and method of application of citric acid and sodium citrate in root conditioning

    Directory of Open Access Journals (Sweden)

    Rodrigo Cavassim

    2012-06-01

    Full Text Available OBJECTIVES: The aim of this study was to establish the parameters of concentration, time and mode of application of citric acid and sodium citrate in relation to root conditioning. MATERIAL AND METHODS: A total of 495 samples were obtained and equally distributed among 11 groups (5 for testing different concentrations of citric acid, 5 for testing different concentrations of sodium citrate and 1 control group. After laboratorial processing, the samples were analyzed under scanning electron microscopy. A previously calibrated and blind examiner evaluated micrographs of the samples. Non-parametric statistical analysis was performed to analyze the data obtained. RESULTS: Brushing 25% citric acid for 3 min, promoted greater exposure of collagen fibers in comparison with the brushing of 1% citric acid for 1 minute and its topical application at 1% for 3 min. Sodium citrate exposed collagen fibers in a few number of samples. CONCLUSION: Despite the lack of statistical significance, better results for collagen exposure were obtained with brushing application of 25% citric acid for 3 min than with other application parameter. Sodium citrate produced a few number of samples with collagen exposure, so it is not indicated for root conditioning.

  6. The Accident Sequence Precursor program: Methods improvements and current results

    International Nuclear Information System (INIS)

    Minarick, J.W.; Manning, F.M.; Harris, J.D.

    1987-01-01

    Changes in the US NRC Accident Sequence Precursor program methods since the initial program evaluations of 1969-81 operational events are described, along with insights from the review of 1984-85 events. For 1984-85, the number of significant precursors was consistent with the number observed in 1980-81, dominant sequences associated with significant events were reasonably consistent with PRA estimates for BWRs, but lacked the contribution due to small-break LOCAs previously observed and predicted in PWRs, and the frequency of initiating events and non-recoverable system failures exhibited some reduction compared to 1980-81. Operational events which provide information concerning additional PRA modeling needs are also described

  7. Production of 67Ga citrate injection liquid with butylacetate extraction method

    International Nuclear Information System (INIS)

    Fang Yibing; Li Bo; Liu Peng; Pan Qiyuan; Liu Peihua; Wang Han; Feng Jingling

    1995-01-01

    The distribution ratios D for Ga(III) at trace concentration in the HCl-butylacetate extraction system are measured. It showed that the D in 6 mol/l HCl is 5 x 10 2 which is maximum in 3-8 mol/l HCl. The extraction rates E in 5.5-8 mol/l HCl at phase ratio of 1 are ≥98% and ≥96% respectively when the concentration of ZnCl 2 in the solution are 0 and ≤2 mol/l. A butylacetate extraction method for the production of 67 Ga citrate injection liquid from Zn target irradiated by proton beam is developed. The optimal acidity of extraction is 6 mol/l HCl. The concentration of ZnCl 2 is adjusted to ≤2.0 mol/l and the impurity of Fe(III) in solution is reduced to Fe(II) with 10% TiCl 3 before extraction. The 67 Ga in organic phase is then stripped with water. The radionuclidic purity of the product is 100% while the radiochemical purity >90%. The amounts of Zn, Ti, Fe, Cu, Cd and Pb in the injection are below or near 1 mg/l. The test of abnormal toxicity is negative. The quality of the injection meets the requirements of both the Chinese and the United States Pharmacopoeia. The chemical yield is (92 +- 2)% while the time of operation is <3 h

  8. Voltammetric method for the determination of sildenafil citrate (Viagra) in pure form and in pharmaceutical formulations.

    Science.gov (United States)

    Tyszczuk, Katarzyna; Korolczuk, Mieczyslaw

    2010-06-01

    A highly sensitive and simple voltammetric method for the determination of sildenafil citrate (SC) was developed. The method is based on the accumulation by adsorption of SC on a lead film modified glassy carbon electrode (LF/GCE) and then the reduction of SC throughout the stripping step. During the determinations of SC at the lead film electrode three adsorptive stripping voltammetric peaks at -1.2, -1.33 and -1.45V were observed. The respective response selected for identification and quantification has been evaluated with respect to the composition and pH of the supporting electrolyte, the potential and the time of the lead film formation, the potential and the time of the SC accumulation and other variables. Experimental results indicate an excellent linear correlation between the peak current and concentration in the range of 2x10(-9)-1.5x10(-7)mol/L (for peaks 1 and 2) and 1x10(-8)-1.5x10(-7)mol/L (for the peak 3). The detection limits (LOD) for SC following 30s of accumulation time were equal to 9x10(-10)mol/L (for peaks 1 and 2) and 4.5x10(-9)mol/L (for the peak 3). The method was successfully applied to the determination of SC in the tablets (Viagra 25 and Viagra 50) and average the contents were in close agreement with those quoted by the manufacturer and with those obtained by the reported spectrophotometric method and voltammetric method using a hanging mercury drop electrode. Copyright 2009 Elsevier B.V. All rights reserved.

  9. Methods of forming single source precursors, methods of forming polymeric single source precursors, and single source precursors and intermediate products formed by such methods

    Science.gov (United States)

    Fox, Robert V.; Rodriguez, Rene G.; Pak, Joshua J.; Sun, Chivin; Margulieux, Kelsey R.; Holland, Andrew W.

    2012-12-04

    Methods of forming single source precursors (SSPs) include forming intermediate products having the empirical formula 1/2{L.sub.2N(.mu.-X).sub.2M'X.sub.2}.sub.2, and reacting MER with the intermediate products to form SSPs of the formula L.sub.2N(.mu.-ER).sub.2M'(ER).sub.2, wherein L is a Lewis base, M is a Group IA atom, N is a Group IB atom, M' is a Group IIIB atom, each E is a Group VIB atom, each X is a Group VIIA atom or a nitrate group, and each R group is an alkyl, aryl, vinyl, (per)fluoro alkyl, (per)fluoro aryl, silane, or carbamato group. Methods of forming polymeric or copolymeric SSPs include reacting at least one of HE.sup.1R.sup.1E.sup.1H and MER with one or more substances having the empirical formula L.sub.2N(.mu.-ER).sub.2M'(ER).sub.2 or L.sub.2N(.mu.-X).sub.2M'(X).sub.2 to form a polymeric or copolymeric SSP. New SSPs and intermediate products are formed by such methods.

  10. Methods of forming single source precursors, methods of forming polymeric single source precursors, and single source precursors formed by such methods

    Science.gov (United States)

    Fox, Robert V.; Rodriguez, Rene G.; Pak, Joshua J.; Sun, Chivin; Margulieux, Kelsey R.; Holland, Andrew W.

    2014-09-09

    Methods of forming single source precursors (SSPs) include forming intermediate products having the empirical formula 1/2{L.sub.2N(.mu.-X).sub.2M'X.sub.2}.sub.2, and reacting MER with the intermediate products to form SSPs of the formula L.sub.2N(.mu.-ER).sub.2M'(ER).sub.2, wherein L is a Lewis base, M is a Group IA atom, N is a Group IB atom, M' is a Group IIIB atom, each E is a Group VIB atom, each X is a Group VIIA atom or a nitrate group, and each R group is an alkyl, aryl, vinyl, (per)fluoro alkyl, (per)fluoro aryl, silane, or carbamato group. Methods of forming polymeric or copolymeric SSPs include reacting at least one of HE.sup.1R.sup.1E.sup.1H and MER with one or more substances having the empirical formula L.sub.2N(.mu.-ER).sub.2M'(ER).sub.2 or L.sub.2N(.mu.-X).sub.2M'(X).sub.2 to form a polymeric or copolymeric SSP. New SSPs and intermediate products are formed by such methods.

  11. Method for forecasting an earthquake from precursor signals

    International Nuclear Information System (INIS)

    Farnworth, D.F.

    1996-01-01

    A method for forecasting an earthquake from precursor signals by employing characteristic first electromagnetic signals, second, seismically induced electromagnetic signals, seismically induced mechanical signals, and infrasonic acoustic signals which have been observed to precede an earthquake. From a first electromagnetic signal, a magnitude, depth beneath the surface of the earth, distance, latitude, longitude, and first and second forecasts of the time of occurrence of the impending earthquake may be derived. From a second, seismically induced electromagnetic signal and the mechanical signal, third and fourth forecasts of the time of occurrence of an impending earthquake determined from the analysis above, a magnitude, depth beneath the surface of the earth and fourth and fifth forecasts of the time of occurrence of the impending earthquake may be derived. The forecasts of time available from the above analyses range from up to five weeks to substantially within one hour in advance of the earthquake. (author)

  12. Summary of ceramic pigments by polymer precursors Pechini method

    International Nuclear Information System (INIS)

    Silva, E.M. da; Galvao, S.B.; Paskocimas, C.A.

    2010-01-01

    In this work were synthesized nitrate chromium nitrate and iron-doped titanium oxide by the polymeric precursor method, for application as ceramic pigments. The stains were developed between the temperatures 700 deg C to 1000 deg C, in green for chromium oxide and orange for iron. Noticing an increase of its opacity by increasing temperature. Characterization by thermogravimetry (TG) showed strong thermo decomposition from 355 deg C for the chromium oxide and thermo decomposition gradual for the iron. By analysis of X-ray diffraction revealed the formation of crystalline phases as Iron Titanate (FeTiO3) and Chrome Titanate (CrTiO3), respectively. The scanning electron microscopy showed the formation of rounded particles for both oxides. Thus, the synthesized oxides were within the requirements to be applied as pigments and shown to be possible to propose its use in ceramic materials. (author)

  13. Precursors of chicken flavor. II. Identification of key flavor precursors using sensory methods.

    Science.gov (United States)

    Aliani, Michel; Farmer, Linda J

    2005-08-10

    Sensory evaluation was used to identify flavor precursors that are critical for flavor development in cooked chicken. Among the potential flavor precursors studied (thiamin, inosine 5'-monophosphate, ribose, ribose-5-phosphate, glucose, and glucose-6-phosphate), ribose appears most important for chicken aroma. An elevated concentration (added or natural) of only 2-4-fold the natural concentration gives an increase in the selected aroma and flavor attributes of cooked chicken meat. Assessment of the volatile odor compounds by gas chromatography-odor assessment and gas chromatography-mass spectrometry showed that ribose increased odors described as "roasted" and "chicken" and that the changes in odor due to additional ribose are probably caused by elevated concentrations of compounds such as 2-furanmethanethiol, 2-methyl-3-furanthiol, and 3-methylthiopropanal.

  14. Non-invasive method for in vivo detection of chlorophyll precursors

    DEFF Research Database (Denmark)

    Kristiansen, Kim Anker; Khrouchtchova, Anastassia; Stenbæk, Anne

    2009-01-01

    Traditionally chlorophyll (Chl) and Chl precursors have been studied in vitro or in leaf tissue at low temperature. These methods are destructive and make it impossible to work with the same individual plant later on. In this paper we present a method for in vivo detection of Chl and its precursors...... is compared to current methods. Furthermore, we report on optimization of the spectral scanning method with the aim to minimize the excitation light-evoked photo-conversion of the chlorophyll precursors....

  15. Method to determine the sticking coefficient of precursor molecules in atomic layer deposition

    International Nuclear Information System (INIS)

    Rose, M.; Bartha, J.W.

    2009-01-01

    A method to determine the sticking coefficient of precursor molecules used in atomic layer deposition (ALD) will be introduced. The sticking coefficient is an interesting quantity for comparing different ALD processes and reactors but it cannot be observed easily. The method relies on free molecular flow in nanoscale cylindrical holes. The sticking coefficient is determined for tetrakis(dimethylamino)titanium in combination with ozone. The proposed method can be applied independent of the type of reactor, precursor delivery system and precursors.

  16. Properties of Y Ba2 Cu3 O7-δ-Ag superconductors prepared by the citrate method

    International Nuclear Information System (INIS)

    Fonseca, F.C.; Muccillo, R.

    1996-01-01

    Y Ba 2 Cu 3 O 7-δ (123) ceramic superconductor and YBa 2 Cu 3 O 7-δ - Ag composite superconductors have been prepared by the citrate method. Microstructural analysis has been done by X-ray diffractometry and optical ceramography. The superconducting behaviour has been studied by 4-probe dc resistivity in the 77 K - 140 K temperature range. Silver percolation in the ceramic matrix was studied by electrical resistivity measurements at room temperature; the percolation threshold was found to be approximately 25 vol% (35.5 wt%) Ag. Specimens with silver addition showed improvement in the flexural strength of the 123 compound. The main results show that the critical temperature does not depend on the silver content in the composite specimens, and that approximately 3 wt% (1.8 vol%) Ag doping yields an optimized composite superconductor from the microstructural point of view, with platelet-like grain shapes. (author)

  17. Methods of making copper selenium precursor compositions with a targeted copper selenide content and precursor compositions and thin films resulting therefrom

    Science.gov (United States)

    Curtis, Calvin J [Lakewood, CO; Miedaner, Alexander [Boulder, CO; van Hest, Marinus Franciscus Antonius Maria; Ginley, David S [Evergreen, CO; Leisch, Jennifer [Denver, CO; Taylor, Matthew [West Simsbury, CT; Stanbery, Billy J [Austin, TX

    2011-09-20

    Precursor compositions containing copper and selenium suitable for deposition on a substrate to form thin films suitable for semi-conductor applications. Methods of forming the precursor compositions using primary amine solvents and methods of forming the thin films wherein the selection of temperature and duration of heating controls the formation of a targeted species of copper selenide.

  18. Nonstoichiometry and phase stability of Al and Cr substituted Mg ferrite nanoparticles synthesized by citrate method

    Energy Technology Data Exchange (ETDEWEB)

    Ateia, Ebtesam E.; Mohamed, Amira T., E-mail: atawfik@sci.cu.edu.eg

    2017-03-15

    The spinel ferrite Mg{sub 0.7}Cr{sub 0.3}Fe{sub 2}O{sub 4}, and Mg{sub 0.7}Al{sub 0.3}Fe{sub 2}O{sub 4} were prepared by the citrate technique. All samples were characterized by X-ray diffraction (XRD), Field Emission Scanning Electron Microscopy (FESEM), High Resolution Transmission Electron Micrographs (HRTEM), Energy Dispersive X ray Spectroscopy (EDAX) and Atomic Force Microscope (AFM). XRD confirmed the formation of cubic spinel structure of the investigated samples. The average crystallite sizes were found to be between 24.7 and 27.5 nm for Al{sup 3+} and Mg{sup 2+} respectively. The substitution of Cr{sup 3+}/Al{sup 3+} in place of Mg{sup 2+} ion initiates a crystalline anisotropy due to large size mismatch between Cr /Al and Mg{sup 2+}, which creates strain inside the crystal volume. According to VSM results, by adding Al{sup 3+} or Cr{sup 3+} ions at the expense of Mg{sup 2+}, the saturation magnetization increased. The narrow hysteresis loop of the samples indicates that the amount of dissipated energy is small, which is desirable for soft magnetic applications. Magnetic dynamics of the samples were studied by measuring magnetic susceptibility versus temperature at different magnetic fields. The band gap energy, which was calculated from near infrared (NIR) and visible (VIS) reflectance spectra using the Kubelka-Munk function, decreases with increasing the particle size. Furthermore, the band gaps were quite narrow (1.5–1.7 eV), hence the investigated samples could act as visible light driven photo catalysts. To sum up the addition of trivalent Al{sup 3+}, and Cr{sup 3+} ions enhanced the optical, magnetic and structure properties of the samples. Mg{sub 0.7} Cr{sub 0.3}Fe{sub 2}O{sub 4} sample will be a better candidate for the optical applications and will also be a guaranteeing hopeful for technological applications. - Highlights: • Nanoparticles of (Mg{sub 0.7} Al{sub 0.3} Fe{sub 2}O{sub 4}) ferrite are the potential candidates for various

  19. Method for the preparation of carbon fiber from polyolefin fiber precursor

    Energy Technology Data Exchange (ETDEWEB)

    Naskar, Amit Kumar; Hunt, Marcus Andrew; Saito, Tomonori

    2017-11-28

    Methods for the preparation of carbon fiber from polyolefin fiber precursor, wherein the polyolefin fiber precursor is partially sulfonated and then carbonized to produce carbon fiber. Methods for producing hollow carbon fibers, wherein the hollow core is circular- or complex-shaped, are also described. Methods for producing carbon fibers possessing a circular- or complex-shaped outer surface, which may be solid or hollow, are also described.

  20. Method for the preparation of carbon fiber from polyolefin fiber precursor, and carbon fibers made thereby

    Science.gov (United States)

    Naskar, Amit Kumar; Hunt, Marcus Andrew; Saito, Tomonori

    2015-08-04

    Methods for the preparation of carbon fiber from polyolefin fiber precursor, wherein the polyolefin fiber precursor is partially sulfonated and then carbonized to produce carbon fiber. Methods for producing hollow carbon fibers, wherein the hollow core is circular- or complex-shaped, are also described. Methods for producing carbon fibers possessing a circular- or complex-shaped outer surface, which may be solid or hollow, are also described.

  1. Effect of lanthanide on the microstructure and structure of LnMn0.5Fe0.5O3 nanoparticles with Ln=La, Pr, Nd, Sm and Gd prepared by the polymer precursor method

    International Nuclear Information System (INIS)

    Romero, Mariano; Faccio, Ricardo; Martínez, Javier; Pardo, Helena; Montenegro, Benjamín; Plá Cid, Cristiani Campos; Pasa, André A.

    2015-01-01

    The synthesis of LnMn 0.5 Fe 0.5 O 3 perovskite nanoparticles by the polymer precursor method showed a strong intrinsic dependence with different lanthanides (Ln=La, Pr, Nd, Sm and Gd). The polymerization level reached in the polymer precursor was proportional to the atomic number of lanthanide with exception of samarium, which showed the formation of a different precursor based in a citrate chelate with ethyleneglycol bonded as adduct. The increasing level of polymerization of the polymer precursors showed the formation of large-size perovskite nanoparticles after its calcination. SAXS and TEM analyses suggested that nanoparticles obtained, using this method, have a squared-like microstructure in connection with the polymer precursor microstructure. Structural analysis showed an orthorhombic structure with a slight decline in the Jahn–Teller distortion when the atomic number of lanthanide increases. Mössbauer spectroscopy showed the presence of a majority site in agreement with the Pbnm orthorhombic structure best fitted with Rietveld refinements and in some cases, a more distorted site attributed to local inhomogeneities and oxygen vacancies. - Highlights: • Precursor polymerization level is lower in the presence of lighter lanthanides. • Lighter lanthanide perovskite nanoparticles after calcination are lower-sized. • Nanoparticles obtained by this method have lamellae microstructure. • Jahn–Teller distortion declines for heavier lanthanide perovskites. • Oxygen vacancy phase was observed in lighter lanthanide perovskites

  2. Measurement of Total Free Iron in Soils by H2S Chemisorption and Comparison with the Citrate Bicarbonate Dithionite Method

    Directory of Open Access Journals (Sweden)

    Shui-Sheng Fan

    2016-01-01

    Full Text Available Free iron is one of the major analytical items for soil basic properties. It is also an important indicator for understanding the genesis of soil, soil classification, and soil distribution behavior. In this study, an alternative analytical method (chemisorption based on thermodynamic knowledge was proposed for measurement of total free iron oxides in soils. Several representative soil samples belonging to alfisols, ultisols, inceptisols, and entisols were collected from Taiwan and tested by the chemisorption, and the estimated total free iron oxides were compared with those measured from the traditional citrate bicarbonate dithionite (CBD method. Experimental results showed that the optimal operating temperature was found to be at 773 K and the carbon monoxide (CO is the best gaseous reagent to promote the formation of FeS. The estimated total free iron oxides for soil samples determined from the chemisorption in the presence of CO were very close to those from the CBD technique. The result of regression indicates that the estimated total free iron is strongly correlated with the CBD-Fe content (R2=0.999 in the presence of CO.

  3. 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)

  4. Summary of ceramic pigments by polymer precursors Pechini method; Sintese de pigmentos ceramicos pelo metodo dos precursores polimericos

    Energy Technology Data Exchange (ETDEWEB)

    Silva, E.M. da; Galvao, S.B.; Paskocimas, C.A., E-mail: everlania_siva@yahoo.com.b [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil)

    2010-07-01

    In this work were synthesized nitrate chromium nitrate and iron-doped titanium oxide by the polymeric precursor method, for application as ceramic pigments. The stains were developed between the temperatures 700 deg C to 1000 deg C, in green for chromium oxide and orange for iron. Noticing an increase of its opacity by increasing temperature. Characterization by thermogravimetry (TG) showed strong thermo decomposition from 355 deg C for the chromium oxide and thermo decomposition gradual for the iron. By analysis of X-ray diffraction revealed the formation of crystalline phases as Iron Titanate (FeTiO3) and Chrome Titanate (CrTiO3), respectively. The scanning electron microscopy showed the formation of rounded particles for both oxides. Thus, the synthesized oxides were within the requirements to be applied as pigments and shown to be possible to propose its use in ceramic materials. (author)

  5. Layered niobate KNb3O8 synthesized by the polymeric precursor method

    International Nuclear Information System (INIS)

    Souza, J.K.D. de; Honório, L.M.C.; Torres, S.M.; Santos, I.M.G.; Maia, A.S.; Ferreira, J.M.

    2018-01-01

    The polymeric precursor method was used for the synthesis of KNb 3 O 8 and compared to the solid-state method. The materials were characterized by X-ray diffraction (XRD), infrared spectroscopy, Raman spectroscopy, scanning electron microscopy, and determination of surface area and total pore volume by nitrogen isotherms at 77 K. The material prepared by the polymeric precursor method was single-phase while K 2 Nb 4 O 11 was obtained as secondary phase when the solid state method was used, as evidenced by the XRD patterns and the Raman spectra. The morphology of the materials was significantly altered by the synthesis method, as the KNb 3 O 8 prepared by the polymeric precursor method presented a more porous morphology leading to a higher surface area and pore volume. (author)

  6. Applying polarity rapid assessment method and ultrafiltration to characterize NDMA precursors in wastewater effluents.

    Science.gov (United States)

    Chen, Chao; Leavey, Shannon; Krasner, Stuart W; Mel Suffet, I H

    2014-06-15

    Certain nitrosamines in water are disinfection byproducts that are probable human carcinogens. Nitrosamines have diverse and complex precursors that include effluent organic matter, some anthropogenic chemicals, and natural (likely non-humic) substances. An easy and selective tool was first developed to characterize nitrosamine precursors in treated wastewaters, including different process effluents. This tool takes advantages of the polarity rapid assessment method (PRAM) and ultrafiltration (UF) (molecular weight distribution) to locate the fractions with the strongest contributions to the nitrosamine precursor pool in the effluent organic matter. Strong cation exchange (SCX) and C18 solid-phase extraction cartridges were used for their high selectivity for nitrosamine precursors. The details of PRAM operation, such as cartridge clean-up, capacity, pH influence, and quality control were included in this paper, as well as the main parameters of UF operation. Preliminary testing of the PRAM/UF method with effluents from one wastewater treatment plant gave very informative results. SCX retained 45-90% of the N-nitrosodimethylamine (NDMA) formation potential (FP)-a measure of the precursors-in secondary and tertiary wastewater effluents. These results are consistent with NDMA precursors likely having a positively charged amine group. C18 adsorbed 30-45% of the NDMAFP, which indicates that a substantial portion of these precursors were non-polar. The small molecular weight (MW) (10 kDa) fractions obtained from UF were the primary contributors to NDMAFP. The combination of PRAM and UF brings important information on the characteristics of nitrosamine precursors in water with easy operation. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. Synthesis of antimony-doped tin oxide (ATO) nanoparticles by the nitrate-citrate combustion method

    International Nuclear Information System (INIS)

    Zhang Jianrong; Gao Lian

    2004-01-01

    Antimony-doped tin oxide (ATO) nanoparticles having rutile structure have been synthesized by the combustion method using citric acid (CA) as fuel and nitrate as an oxidant, the metal sources were granulated tin and Sb 2 O 3 . The influence of citric acid (fuel) to metal ratio on the average crystallite size, specific surface area and morphology of the nanoparticles has been investigated. X-ray diffraction showed the tin ions were reduced to elemental tin during combustion reaction. The average ATO crystallite size increased with the increase of citric acid (fuel). Powder morphology and the comparison of crystallite size and grain size shows that the degree of agglomeration of the powder decreased with an increase of the ratio. The highest specific surface area was 37.5 m 2 /g when the citric acid to tin ratio was about 6

  8. Method of determination of radiochemical purity of gallium-67 citrate injection

    International Nuclear Information System (INIS)

    Wang Quanji

    1985-01-01

    A simple method is used to compare the effect of five developing agents on the radiochemical purity of neutral products of 67 GaCit and on Rsub(f) values. Two preferable developing agents are recommended as suitable for the identification of 67 GaCit injection in its production. The effect of six pH values of different developing agents on radiochemical purity, Rsub(f) and chromatogram are compared for the neutral products. The results of the experiments show that the ascending paper chromatography with 1:2:4 pyridine/ethanol/water and 85:15 methanol/water is preferable for the determination of the radiochemical purity of 67 GaCit. The other developing agents also can be used if there are not any impurities except gallium radioisotopes

  9. Improved method for measuring transparent exopolymer particles (TEP) and their precursors infresh and saline water

    KAUST Repository

    Villacorte, Loreen O.

    2015-03-01

    Transparent exopolymer particles (TEP) and their precursors produced by phyto-/bacterio-planktons in fresh and marine aquatic environments are increasingly considered as a major contributor to organic/particulate and biological fouling in micro-/ultra-filtration and reverse osmosis membrane (RO) systems. However, currently established methods which are based on Alcian blue (AB) staining and spectrophotometric techniques do not measure TEP-precursors and have the tendency to overestimate concentration in brackish/saline water samples due to interference of salinity on AB staining. Here we propose a new semi-quantitative method which allows measurement of both TEP and their colloidal precursors without the interference of salinity. TEP and their precursors are first retained on 10kDa membrane, rinsed with ultra-pure water, and re-suspended in ultra-pure water by sonication and stained with AB, followed by exclusion of TEP-AB precipitates by filtration and absorbance measurement of residual AB. The concentration is then determined based on the reduction of AB absorbance due to reaction with acidic polysaccharides, blank correction and calibration with Xanthan gum standard. The extraction procedure allows concentration of TEP and their pre-cursors which makes it possible to analyse samples with a wide range of concentrations (down to <0.1mg Xeq/L). This was demonstrated through application of the method for monitoring these compounds in algal cultures and a full-scale RO plant. The monitoring also revealed that concentrations of the colloidal precursors were substantially higher than the concentration of TEP themselves. In the RO plant, complete TEP removal was observed over the pre-treatment processes (coagulation-sedimentation-filtration and ultrafiltration) but the TEP precursors were not completely removed, emphasising the importance of measuring this colloidal component to better understand the role of TEP and acidic polysaccharides in RO membrane fouling.

  10. Methods for conversion of lignocellulosic-derived products to transportation fuel precursors

    Science.gov (United States)

    Lilga, Michael A.; Padmaperuma, Asanga B.

    2017-10-03

    Methods are disclosed for converting a biomass-derived product containing levulinic acid and/or gamma-valerolactone to a transportation fuel precursor product containing diesel like hydrocarbons. These methods are expected to produce fuel products at a reduced cost relative to conventional approaches.

  11. Silicon dioxide obtained by Polymeric Precursor Method; Obtencao de dioxido de silicio pelo Metodo dos Precursores Polimericos

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, C.T.; Granado, S.R.; Lopes, S.A.; Cavalheiro, A.A., E-mail: cinthia_quimica@hotmail.com [Universidade Estadual de Mato Grosso do Sul (CPTREN/UEMS), Navirai, MS (Brazil). Centro de Pesquisas Tecnologicas em Recursos Naturais

    2011-07-01

    The Polymeric Precursor Method is able for obtaining several oxide material types with high surface area even obtained in particle form. Several MO{sub 2} oxide types such as titanium, silicon and zirconium ones can be obtained by this methodology. In this work, the synthesis of silicon oxide was monitored by thermal analysis, XRD and surface area analysis in order to demonstrate the influence of the several synthesis and calcining parameters. Surface area values as higher as 370m2/g and increasing in the micropore volume nm were obtained when the material was synthesized by using ethylene glycol as polymerizing agent. XRD analysis showed that the material is amorphous when calcinated at 600°C in despite of the time of calcining, but the material morphology is strongly influenced by the polymeric resin composition. Using Glycerol as polymerizing agent, the pore size increase and the surface area goes down with the increasing in decomposition time, when compared to ethylene glycol. (author)

  12. 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

  13. Preparation and characterization of TiO{sub 2} doped and MgO stabilized Na–β″-Al{sub 2}O{sub 3} electrolyte via a citrate sol–gel method

    Energy Technology Data Exchange (ETDEWEB)

    Shan, Shi-Jie; Yang, Li-Ping; Liu, Xiao-Min; Wei, Xiao-Ling [College of Materials Science and Engineering, Nanjing University of Technology, 5 Xinmofan Road, Nanjing, Jiangsu 210009 (China); Yang, Hui, E-mail: yanghui@njut.edu.cn [College of Materials Science and Engineering, Nanjing University of Technology, 5 Xinmofan Road, Nanjing, Jiangsu 210009 (China); Shen, Xiao-Dong [College of Materials Science and Engineering, Nanjing University of Technology, 5 Xinmofan Road, Nanjing, Jiangsu 210009 (China)

    2013-06-25

    Highlights: ► TiO{sub 2} doped Na–β″-Al{sub 2}O{sub 3} electrolyte is synthesized via a sol–gel method with C{sub 16}H{sub 36}O{sub 4}Ti as the precursor for TiO{sub 2}. ► The optimized sample contains 90.28% of β″ phase and presents a very high relative density (99.5%). ► The optimized sample exhibits the bending strength up to 180 MPa and an ionic conductivity up to 0.21 S cm{sup −1} (350 °C). -- Abstract: TiO{sub 2} doped and MgO stabilized Na–β″-Al{sub 2}O{sub 3} is synthesized via a citrate sol–gel method starting with Al(NO{sub 3}){sub 3}, NaNO{sub 3}, Mg(NO{sub 3}){sub 2} and C{sub 16}H{sub 36}O{sub 4}Ti (tetrabutyl titanate, abbreviated as TBT). It is found that the TBT amount in the starting materials is the key factor to affect the properties of the final product, therefore, the samples sintered from precursors containing different amounts of TBT are systematically investigated by means of powder X-ray diffraction (XRD) and scanning electron microscopy (SEM). Meanwhile, the relative density, mechanical strength and electrical properties of the prepared samples are also measured. The optimized sample contains 90.28% of β″ phase, exhibits a uniform and compact microstructure with a relative density as high as 99.5% of theoretical density (TD). In addition, this sample exhibits a bending strength up to 180 MPa and an ionic conductivity up to 0.21 S cm{sup −1} at 350 °C.

  14. 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...

  15. Magnetic Properties of Ni-Zn Ferrite Prepared with the Layered Precursor Method

    International Nuclear Information System (INIS)

    Zhou Xin; Hou Zhi-Ling; Li Feng; Qi Xin

    2010-01-01

    We prepare NiZnFe 2 O 4 soft magnetic ferrites with different molar ratios with the layered precursor method and investigate their magnetic properties. In the layered precursor, metal ions are scattered on the layer plate in a certain way on account of the effect of lowest lattice energy and lattice orientation. After high temperature calcinations, spinel ferrites with uniform structural component and single magnetic domain can be obtained, and the magnetic property is improved greatly. NiZnFe 2 O 4 ferrites prepared have the best specific saturation magnetization of 79.15 emu·g −1 , higher than that of 68 emu·g −1 prepared by the chemical co-precipitation method and that of 59 emu·g −1 prepared by the emulsion-gel method. Meanwhile the coercivity of NiZnFe 2 O 4 ferrites prepared by layered precursor method is 14 kA·m −1 , lower than that of 50 emu·g −1 prepared by the co-precipitation method and that of 59 emu·g −1 prepared by the emulsion-gel method. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

  16. 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.

  17. NiTiO3 powders obtained by polymeric precursor method: Synthesis and characterization

    International Nuclear Information System (INIS)

    Lopes, K.P.; Cavalcante, L.S.; Simoes, A.Z.; Varela, J.A.; Longo, E.; Leite, E.R.

    2009-01-01

    Nickel titanate (NiTiO 3 ) powders were synthesized by the polymeric precursor method after thermal treatment at different temperatures for 2 h in air atmosphere. The decomposition of the precursors was monitored by differential scanning calorimetry and thermogravimetric analysis. The NiTiO 3 powders presented a reduction in the specific surface area and increase of the average particle size with the evolution of the temperature. The structural evolution of NiTiO 3 phase was accompanied by X-ray diffraction and Fourier transform Raman spectroscopy. By scanning electron microscopy was revealed the agglomerated nature of very fine particles of NiTiO 3 powders annealed from 600 to 1000 deg. C

  18. Er:YAB nanoparticles and vitreous thin films by the polymeric precursor method

    Energy Technology Data Exchange (ETDEWEB)

    Maia, Lauro J. Q., E-mail: lauro@if.sc.usp.b [Universidade de Sao Paulo, Grupo Crescimento de Cristais e Materiais Ceramicos, Departamento de Fisica e Ciencia dos Materiais, Instituto de Fisica de Sao Carlos (Brazil); Ibanez, Alain; Ortega, Luc [Laboratoire de Cristallographie CNRS associe a l' Universite Joseph Fourier et a l' INPG (France); Mastelaro, Valmor R.; Hernandes, Antonio C. [Universidade de Sao Paulo, Grupo Crescimento de Cristais e Materiais Ceramicos, Departamento de Fisica e Ciencia dos Materiais, Instituto de Fisica de Sao Carlos (Brazil)

    2008-12-15

    The synthesis of Y{sub 0.9}Er{sub 0.1}Al{sub 3}(BO{sub 3}){sub 4} crystalline powders and vitreous thin films were studied. Precursor solutions were obtained using a modified polymeric precursor method using d-sorbitol as complexant agent. The chemical reactions were described. Y{sub 0.9}Er{sub 0.1}Al{sub 3}(BO{sub 3}){sub 4} composition presents good thermal stability with regard to crystallization. The Y{sub 0.9}Er{sub 0.1}Al{sub 3}(BO{sub 3}){sub 4} crystallized phase can be obtained at 1,150 {sup o}C, in agreement with other authors. Crack- and porosity-free films were obtained with very small grain size and low RMS roughness. The films thickness revealed to be linearly dependent on precursor solution viscosity, being the value of 25 mPa s useful to prepare high-quality amorphous multi-layers (up to {approx} 800 nm) at 740 {sup o}C during 2 h onto silica substrates by spin coating with a gyrset technology.

  19. 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.

  20. 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.

  1. Stability-indicating HPLC-DAD methods for determination of two binary mixtures: Rabeprazole sodium-mosapride citrate and rabeprazole sodium-itopride hydrochloride.

    Science.gov (United States)

    El-Fatatry, Hamed M; Mabrouk, Mokhtar M; Hewala, Ismail I; Emam, Ehab H

    2014-08-01

    Two selective stability-indicating HPLC methods are described for determination of rabeprazole sodium (RZ)-mosapride citrate (MR) and RZ-itopride hydrochloride (IO) mixtures in the presence of their ICH-stress formed degradation products. Separations were achieved on X-Bridge C18 column using two mobile phases: the first for RZ-MR mixture consisted of acetonitrile: 0.025 M KH 2 PO 4 solution: TEA (30:69:1 v/v; pH 7.0); the second for RZ-IO mixture was at ratio of 25:74:1 (v/v; pH 9.25). The detection wavelength was 283 nm. The two methods were validated and validation acceptance criteria were met in all cases. Peak purity testing using contrast angle theory, relative absorbance and log  A versus the wavelengths plots were presented. The % recoveries of the intact drugs were between 99.1% and 102.2% with RSD% values less than 1.6%. Application of the proposed HPLC methods indicated that the methods could be adopted to follow the stability of their formulations.

  2. Influence of starting precursors and synthesis methods on the physiochemical properties of zirconia

    Energy Technology Data Exchange (ETDEWEB)

    Gaydhankar, T.R., E-mail: tr.gaydhankar@ncl.res.in [Catalysis Division, National Chemical Laboratory, Pune 411008 (India); Jha, R.K. [Catalysis Division, National Chemical Laboratory, Pune 411008 (India); Nikalje, M.D. [Department of Chemistry, University of Pune, Pune 411 007 (India); Waghmare, K.J. [Catalysis Division, National Chemical Laboratory, Pune 411008 (India)

    2014-07-01

    Graphical abstract: Crystallite size of tetragonal phase of the zirconia samples prepared using different synthesis parameters and precursors as a function of calcination temperature. Surface area values of the zirconia samples calcined at 500 and 700 °C are in given brackets. - Highlights: • Zirconia prepared with modified sol–gel method is less stable compared with zirconia prepared by precipitation method. • Optimized synthesis conditions shifted the glow exotherm to higher temperature range indicating better thermal stability. • Tetragonal-zirconia could be synthesized in cost-effective manner using zirconium oxy-nitrate. • In our studies no co-relation between the surface area and crystallite size was observed. - Abstract: Under identical and judiciously pre-optimized synthesis conditions, the influence of different combinations of zirconium sources and/or post treatment conditions on structural properties, thermal stability, phase composition and morphology of zirconia has been investigated. High surface area tetragonal zirconia could be synthesized in a cost-effective manner from 1 M solution of zirconium oxy-nitrate at pH 11 using aqueous ammonia solution as a precipitant when calcined at 400 °C for 3 h. Irrespective of the preparation method, pH and starting precursor, zirconia samples prepared without digestion contained dominant monoclinic phase with some traces of tetragonal phase when calcined at 700 °C. Even though there is linear decrease in surface area with increase in the crystallite size for each sample as a function of calcination temperature, no co-relation between the surface area and crystallite size could be achieved. SEM images show agglomerated and irregular shape particles between 10 to 20 μm.

  3. Fabrication of CdS nanowires with increasing anionic precursor by SILAR method

    Science.gov (United States)

    Dariani, R. S.; Salehi, F.

    2016-05-01

    CdS nanowires were fabricated on glass substrate at room temperature by SILAR method with cadmium nitrate cationic and sodium sulfide anionic precursors. The deposition were done at different S:Cd concentration ratios of 1:1, 3:1, 5:1, and 7:1. Nanowires growth procedure was studied in the mentioned concentrations. The number of immersion cycles was kept constant at 15 cycles. EDX analysis showed that in all stoichiometric ratios, S/Cd composition ratio remains at about unity. Our results indicated that S:Cd concentration ratio of 7:1 had the longest nanowires with hexagonal structure. The main objective of this paper was to produce CdS nanowires with increasing concentration of sulfur.

  4. Nanosized LaCo0.6Fe0.4O3 perovskites synthesized by citrate sol gel auto combustion method

    Directory of Open Access Journals (Sweden)

    Unikoth Megha

    2014-06-01

    Full Text Available LaCo0.6 Fe0.4 O3 (LCFO nanopowder was synthesized from constituent metal nitrates, citric acid and ethylene glycol by citrate sol gel autocombustion method and calcined at different temperatures. The powders were characterized by X-ray diffraction (XRD, scanning electron microscopy (SEM, energy dispersive X-ray analysis (EDAX and Fourier transform infrared spectra (FTIR, whereas dielectric properties were investigated with LCR-meter. The FTIR spectra, taken for the xerogel and the sample calcined at 1000 °C, confirm that the organic groups were removed during calcination and oxide structure was formed. The XRD result shows that LCFO has rhombhohedral crystal structure with R-3C space group and forms single phase after calcination at 600 °C. The activation energy of crystallite growth, determined from the Arrhenius plot, was 17±2 kJ/mol. Surface feature studies of the powders were obtained from SEM. At 1000 °C, dense microstructure with well-shaped grain boundaries was obtained and the average grain size was around 400 nm. EDAX confirms the elemental composition. Finally, from the dielectric studies, it was found that the dielectric constant (εr as well as dielectric loss tangent (tan δ decreases with increase in frequency.

  5. Synthesis and characterization of Al2O3 obtained from the polymeric precursor method using glycerin as a poly alcohol

    International Nuclear Information System (INIS)

    Elicker, C.; Gaier, M.; Almeida, S.R.; Vieiraaa, B.M.; Ratmann, C.W.R.; Pereira, C.M.P. de; Cava, S.S.; Egea, J.J.

    2014-01-01

    In this study, calcium aluminate was synthesized using glycerin to replace ethylene glycol in the polymeric precursor method. The resulting resin was pre-calcined in a muffle at 300 °C for 2 h and the resulting material was calcined at 900 °C for 2 h. The powders were analyzed by XRD, SEM and EDX, TEM, Micro-Raman and IR. The results demonstrated the possibility of using glycerin as an alternative to ethylene glycol in the polymeric precursor method. (author)

  6. Study of hafnium (IV) oxide nanoparticles synthesized by polymerized complex and polymer precursor derived sol-gel methods

    KAUST Repository

    Ramos-Gonzá lez, R.; Garcí a-Cerda, L. A.; Alshareef, Husam N.; Gnade, Bruce E.; Quevedo-Ló pez, Manuel Angel Quevedo

    2010-01-01

    This work reports the preparation and characterization of hafnium (IV) oxide (HfO2) nanoparticles grown by derived sol-gel routes that involves the formation of an organic polymeric network. A comparison between polymerized complex (PC) and polymer precursor (PP) methods is presented. For the PC method, citric acid (CA) and ethylene glycol (EG) are used as the chelating and polymerizable reagents, respectively. In the case of PP method, poly(acrylic acid) (PAA) is used as the chelating reagent. In both cases, different precursor gels were prepared and the hafnium (IV) chloride (HfCl4) molar ratio was varied from 0.1 to 1.0 for the PC method and from 0.05 to 0.5 for the PP method. In order to obtain the nanoparticles, the precursors were heat treated at 500 and 800 °C. The thermal characterization of the precursor gels was carried out by thermogravimetric analysis (TGA) and the structural and morphological characterization by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The XRD patterns of the samples obtained by both methods shows the formation of HfO2 at 500 °C with monoclinic crystalline phase. The PC method exhibited also the cubic phase. Finally, the HfO2 nanoparticles size (4 to 11 nm) was determined by TEM and XRD patterns. © (2010) Trans Tech Publications.

  7. Study of hafnium (IV) oxide nanoparticles synthesized by polymerized complex and polymer precursor derived sol-gel methods

    KAUST Repository

    Ramos-González, R.

    2010-03-01

    This work reports the preparation and characterization of hafnium (IV) oxide (HfO2) nanoparticles grown by derived sol-gel routes that involves the formation of an organic polymeric network. A comparison between polymerized complex (PC) and polymer precursor (PP) methods is presented. For the PC method, citric acid (CA) and ethylene glycol (EG) are used as the chelating and polymerizable reagents, respectively. In the case of PP method, poly(acrylic acid) (PAA) is used as the chelating reagent. In both cases, different precursor gels were prepared and the hafnium (IV) chloride (HfCl4) molar ratio was varied from 0.1 to 1.0 for the PC method and from 0.05 to 0.5 for the PP method. In order to obtain the nanoparticles, the precursors were heat treated at 500 and 800 °C. The thermal characterization of the precursor gels was carried out by thermogravimetric analysis (TGA) and the structural and morphological characterization by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The XRD patterns of the samples obtained by both methods shows the formation of HfO2 at 500 °C with monoclinic crystalline phase. The PC method exhibited also the cubic phase. Finally, the HfO2 nanoparticles size (4 to 11 nm) was determined by TEM and XRD patterns. © (2010) Trans Tech Publications.

  8. High-pressure synthesis of CuBa2Ca3Cu4O10+δ superconductor from precursors prepared by a polymerized complex method

    International Nuclear Information System (INIS)

    Aoba, Tomoya; Bizen, Takeshi; Suzuki, Tsuneo; Nakayama, Tadachika; Suematsu, Hisayuki; Niihara, Koichi; Katsumata, Tetsuhiro; Inaguma, Yoshiyuki

    2011-01-01

    Samples of a CuBa 2 Ca 3 Cu 4 O 10+ δ superconductor were synthesized under a high pressure of 5 GPa at 1100-1200degC for 30 min using precursors produced by solid-state reaction and polymerized complex methods. Compared with the precursors prepared by the solid-state reaction method, the precursors produced by the polymerized complex method have low grain sizes. The superconductive transition temperature of the samples prepared using precursors made by the polymerized complex method was found to be 113 K. The volume fractions of the superconducting phase in the samples prepared using precursors made by the solid-state reaction and polymerized complex methods were 49 and 36%, respectively. From these results, precursors made by the polymerized complex method can be used in the high-pressure synthesis of superconductors similarly to those made by the solid-state reaction method. (author)

  9. Improved method for measuring transparent exopolymer particles (TEP) and their precursors infresh and saline water

    KAUST Repository

    Villacorte, Loreen O.; Ekowati, Yuli; Calix-Ponce, Helga N.; Schippers, Jan Cornelis; Amy, Gary L.; Kennedy, Maria Dolores

    2015-01-01

    Transparent exopolymer particles (TEP) and their precursors produced by phyto-/bacterio-planktons in fresh and marine aquatic environments are increasingly considered as a major contributor to organic/particulate and biological fouling in micro

  10. Nanocystalline ZnO films prepared via polymeric precursor method (Pechini)

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez, C.; Doria, J.; Paucar, C.; Hernandez, M. [Laboratorio de Materiales Ceramicos y Vitreos, Universidad Nacional de Colombia, Sede Medellin, A.A. 568, Medellin (Colombia); Mosquera, A.; Rodriguez, J.E. [Grupo CYTEMAC, Universidad del Cauca, Calle 5 No 4-70, Popayan (Colombia); Gomez, A. [Departamento de Ingenieria de Materiales, Universidad Nacional de Colombia, sede Medellin, A.A. 568, Medellin (Colombia); Baca, E. [Grupo de Ingenieria de Nuevos Materiales, Universidad del Valle, A.A. 25360 Cali (Colombia); Moran, O., E-mail: omoranc@unal.edu.c [Laboratorio de Materiales Ceramicos y Vitreos, Universidad Nacional de Colombia, Sede Medellin, A.A. 568, Medellin (Colombia)

    2010-09-01

    The polymeric precursor method (Pechini) was employed to prepare high-quality nanocrystalline zinc oxide (ZnO) films. Briefly, the process started off with the preparation of a coating solution by the Pechini process followed by a coating of the glass substrates by a dip-coating technique and subsequent heat-treatment of the as-deposited films up to 550 {sup o}C for 30 min. The Rietveld profile analysis of the X-ray diffraction (XRD) spectra revealed the wuerzite structure as expected for ZnO with a P6{sub 3}mc symmetry. No additional peaks were observed that would correspond to any secondary crystalline phase. The average crystallites size was 20 nm as calculated by Sherrer's equation. UV-vis spectroscopy showed sharp ultraviolet absorption edges at {approx}380 nm. The absorption edge analysis yielded optical band gap energy of 3.24 eV with electronic transition of the direct transition type. The Fourier transform infrared (FTIR) analysis showed asymmetric and symmetric stretching modes of the carboxyl group (C=O). Scanning electron microscope (SEM) analysis revealed a crack-free surface morphology indicating that coating of the amorphous glass substrates was homogeneous on large surface areas. The temperature dependent conductivity featured a typical semiconducting-like behavior with resistivity approaching 3x10{sup -1} {Omega} cm at 220 K.

  11. Structural characterization and frictional properties of carbon nanotube/alumina composites prepared by precursor method

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, Go [Institute of Fluid Science, Tohoku University, 2-1-1 Katahira, Aobaku, Sendai 980-8577 (Japan); Fracture and Reliability Research Institute, Tohoku University, 6-6-11-707 Aza-Aoba, Aramaki, Aobaku, Sendai 980-8579 (Japan)], E-mail: gyamamoto@rift.mech.tohoku.ac.jp; Omori, Mamoru; Yokomizo, Kenji; Hashida, Toshiyuki [Fracture and Reliability Research Institute, Tohoku University, 6-6-11-707 Aza-Aoba, Aramaki, Aobaku, Sendai 980-8579 (Japan); Adachi, Koshi [Graduate School of Engineering, Tohoku University, 6-6-01 Aza-Aoba, Aramaki, Aobaku, Sendai 980-8579 (Japan)

    2008-02-25

    Multi-walled carbon nanotube (MWCNT)/Al{sub 2}O{sub 3} composites with MWCNTs content up to 10 mass% were prepared by precursor method. XRD analysis revealed that MWCNT/Al{sub 2}O{sub 3} composites were successfully synthesized by the dehydration of aluminum hydroxide-MWCNTs mixture at 1500 deg. C in vacuum. The steady-state friction coefficient ({mu}) of the composites decreased with increasing up to 4 mass% MWCNT and stayed constant ({mu} = 0.33) with further addition of MWCNT, which value was substantially lower than that of MWCNT-free monolithic Al{sub 2}O{sub 3} ({mu} = 0.57). Microstructural observations showed that resultant friction behavior may be related to the smearing of transferred film over the contact area, which was expected to permit easy shear and then help to achieve a lubricating effect during sliding. However, fracture property tests have shown that no improvement of the fracture strength and fracture toughness of the composites was achieved by addition of MWCNTs. It may be mainly due to the agglomeration of MWCNTs and the weak interface between MWCNTs and the Al{sub 2}O{sub 3} matrix.

  12. Structural characterization and frictional properties of carbon nanotube/alumina composites prepared by precursor method

    International Nuclear Information System (INIS)

    Yamamoto, Go; Omori, Mamoru; Yokomizo, Kenji; Hashida, Toshiyuki; Adachi, Koshi

    2008-01-01

    Multi-walled carbon nanotube (MWCNT)/Al 2 O 3 composites with MWCNTs content up to 10 mass% were prepared by precursor method. XRD analysis revealed that MWCNT/Al 2 O 3 composites were successfully synthesized by the dehydration of aluminum hydroxide-MWCNTs mixture at 1500 deg. C in vacuum. The steady-state friction coefficient (μ) of the composites decreased with increasing up to 4 mass% MWCNT and stayed constant (μ = 0.33) with further addition of MWCNT, which value was substantially lower than that of MWCNT-free monolithic Al 2 O 3 (μ = 0.57). Microstructural observations showed that resultant friction behavior may be related to the smearing of transferred film over the contact area, which was expected to permit easy shear and then help to achieve a lubricating effect during sliding. However, fracture property tests have shown that no improvement of the fracture strength and fracture toughness of the composites was achieved by addition of MWCNTs. It may be mainly due to the agglomeration of MWCNTs and the weak interface between MWCNTs and the Al 2 O 3 matrix

  13. Nanogravimetric studies of tungsten oxide thin films obtained by the polymeric precursor method

    International Nuclear Information System (INIS)

    Fernandes, V.C.; Santos, M.C.; Bulhoes, L.O.S.

    2007-01-01

    In this work, the intercalation/de-intercalation process of Li + ions in the tungsten oxide matrix was investigated. The reaction mechanism involved was also investigated. The WO 3 films, prepared by the polymeric precursor method, were deposited on a Pt covered quartz crystal using the dip-coating technique. The electrolyte was 0.1 mol L -1 LiClO 4 in acetonitrile. The morphology and structure of the deposit was accomplished by scanning electron microscopy and X-ray diffraction, respectively. In the electrochemical quartz crystal nanobalance results, it was observed that the mass transport as well as the kinetic processes involved are facilitated in the films cycled at lower potential sweep-rates. The mass variation data as a function of the charge variations in the anodic and cathodic regions indicate the participation of solvent molecules (acetonitrile) during the Li + ion intercalation/de-intercalation process. This was confirmed by the development of a model of the species flux as a function of the potential

  14. Synthesizing aspartyl-phenylalanine methyl precursor by enzymatic method. Kosoho ni yoru asuparutemu zenkutai no gosei

    Energy Technology Data Exchange (ETDEWEB)

    Hirata, M. (Waseda University, Tokyo (Japan)); Hirata, A. (Waseda University, Tokyo (Japan). School of Science and Engineering)

    1991-10-01

    Demand for aspartyl-phenylalanine methyl, an amino acid based artificial sweetener, is increasing for use by people on diet. The material is manufactured by making a precursor through dehydrating and condensing N-protective{sub L}-asparagine acid and {sub L}-phenylalanine methyl ester, and then removing the protective group. While the manufacturing methods include chemical process and enzymatic process, this paper introduces various researches done mainly by the latter process. The enzymatic process is simpler and safer than the chemical process, allowing experiments to be carried out easily. However, since the reaction equilibrium is biased more on the decomposition side than the synthesis side, it should be shifted to the synthesis side. Such operations may be carried out as separating the products simultaneously with the reaction, adding organic solvents, and operating the reaction in an organic solvent. The last operation, for example, reduces the concentration of liquid produced by the reaction by use of either water soluble or slightly soluble organic solvent, and improves the yield. It also has an advantage that relatively stable fixing enzymes can be adjusted by use of hydrophilic carriers. 68 refs., 8 figs.

  15. Size of the coming solar cycle 24 based on Ohl's Precursor Method, final estimate

    Directory of Open Access Journals (Sweden)

    R. P. Kane

    2010-07-01

    Full Text Available In Ohl's Precursor Method (Ohl, 1966, 1976, the geomagnetic activity during the declining phase of a sunspot cycle is shown to be well correlated with the size (maximum sunspot number Rz(max of the next cycle. For solar cycle 24, Kane (2007a used aa(min=15.5 (12-month running mean, which occurred during March–May of 2006 and made a preliminary estimate Rz(max=124±26 (12-month running mean. However, in the next few months, the aa index first increased and then decreased to a new low value of 14.8 in July 2007. With this new low value, the prediction was Rz(max=117±26 (12-month running mean. However, even this proved a false signal. Since then, the aa values have decreased considerably and the last 12-monthly value is 8.7, centered at May 2009. For solar cycle 24, using aa(min=8.7, the latest prediction is, Rz(max=58.0±25.0.

  16. Effect of heat absorbing powder addition on cell morphology of porous titanium composite manufactured by reactive precursor method

    International Nuclear Information System (INIS)

    Kobashi, Makoto; Kamiya, Yoshinori; Kanetake, Naoyuki

    2012-01-01

    Open-cell structured porous titanium/ceramics composite was synthesized by a reactive precursor method using titanium and boron carbide (B 4 C) as reactant powders. Pore morphology was controlled by adding heat absorbing powder (titanium diboride: TiB 2 ) in the Ti+B 4 C blended powder. The effects of molar blending ratio of titanium and B 4 C and the amount of heat absorbing powder addition on the cell morphology (either open or closed) were investigated. Fine and homogeneous open-cell structure was achieved by adding appropriate amount of heat absorbing agent powder (>15 vol%), and the relative density of the specimen after the reaction became closer to that of the precursor by increasing TiB 2 volume fraction. When the volume fraction of TiB 2 addition was 20%, the open-cell fraction was maintained as 1.0 regardless of the relative density of the precursor.

  17. Nano structured TiO2 thin films by polymeric precursor method

    International Nuclear Information System (INIS)

    Stroppa, Daniel Grando; Giraldi, Tania Regina; Leite, Edson Roberto; Varela, Jose Arana; Longo, Elson

    2008-01-01

    This work focuses in optimizing setup for obtaining TiO 2 thin films by polymeric precursor route due to its advantages on stoichiometric and morphological control. Precursor stoichiometry, synthesis pH, solids concentration and rotation speed at deposition were optimized evaluating thin films morphology and thickness. Thermogravimetry and NMR were applied for precursor's characterization and AFM, XRD and ellipsometry for thin films evaluation. Results showed successful attainment of homogeneous nanocrystalline anatase TiO 2 thin films with outstanding control over morphological characteristics, mean grain size of 17 nm, packing densities between 57 and 75%, estimated surface areas of 90 m 2 /g and monolayers thickness within 20 and 128 nm. (author)

  18. In vitro method determing sensitivity of anticancer agents by incorporation of radioactive precursors

    International Nuclear Information System (INIS)

    Sakakibara, Satoshi

    1983-01-01

    A new sensitivity test of anticancer agents was developed to measure the lethal effects of cancer cells by the incorporation of radioactive precursors. The thousand cancer cells were cultured in a microplate in the presence of anticancer agents. These cells were exposed to radioactive precursors. Two or three days later, the cancer cells were harvested on a glass fiver filter by a multiple automatic cell-harvester and the incorporation of precursors was counted by a liquid scintillation counter. In this study, the in vivo results of drug testing in animal model systems were compared with drug sensitivities. Mice inoculated Ehrlich ascites cells were treated with various kinds of anticancer drugs. The development of the cells was compatible with the result of the sensitivity test. The growths of Lauson and ME-180 cells derived from human cancers implanted subcutaneously to nude mice were also well correlated with this sensitivity test. (author)

  19. 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.

  20. 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.

  1. 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.

  2. Selection of events at Ukrainian NPPs using the algorithm based on accident precursor method

    International Nuclear Information System (INIS)

    Vorontsov, D.V.; Lyigots'kij, O.Yi.; Serafin, R.Yi.; Tkachova, L.M.

    2012-01-01

    The paper describes a general approach to the first stage of research and development on analysis of Ukrainian NPP operation events from 1 January 2000 to 31 December 2010 using the accident precursor approach. Groups of potentially important events formed after their selection and classification are provided

  3. Controlled synthesis of ZnO hollow microspheres via precursor-template method and its gas sensing property

    International Nuclear Information System (INIS)

    Tian, Yu; Li, Jinchai; Xiong, Hui; Dai, Jiangnan

    2012-01-01

    Highlights: ► Zn powder as precursor template for synthesis ZnO hollow spheres. ► Different precursor templates result in different ZnO nanostructures. ► Different experimental conditions enable growth of different surface morphologies of ZnO sphere. ► ZnO hollow sphere materials have good gas sensing performance for detecting ethanol gas. - Abstract: Using Zn powder as precursor templates, ZnO hollow microspheres were successfully prepared by thermal evaporation method and characterized by X-ray diffraction analysis, scanning electron microscope and transmission electron microscope. It was found that different size and shape of precursor resulted in different ZnO nanostructures. When varying experimental conditions, such as air flow rate and working pressure, ZnO hollow spheres with different surface morphologies could be obtained. The advantages of the present synthetic technology are simple, relatively low cost, and high reproducibility. A gas sensor was fabricated from the as-prepared ZnO hollow microspheres and tested to the ethanol gas at different operating temperatures.

  4. A Co-Precursor Approach Coupled with a Supercritical Modification Method for Constructing Highly Transparent and Superhydrophobic Polymethylsilsesquioxane Aerogels.

    Science.gov (United States)

    Lei, Chaoshuai; Li, Junning; Sun, Chencheng; Yang, Hailong; Xia, Tao; Hu, Zijun; Zhang, Yue

    2018-03-30

    Polymethylsilsesquioxane (PMSQ) aerogels obtained from methyltrimethoxysilane (MTMS) are well-known high-performance porous materials. Highly transparent and hydrophobic PMSQ aerogel would play an important role in transparent vacuum insulation panels. Herein, the co-precursor approach and supercritical modification method were developed to prepare the PMSQ aerogels with high transparency and superhydrophobicity. Firstly, benefiting from the introduction of tetramethoxysilane (TMOS) in the precursor, the pore structure became more uniform and the particle size was decreased. As the TMOS content increased, the light transmittance increased gradually from 54.0% to 81.2%, whereas the contact angle of water droplet decreased from 141° to 99.9°, ascribed to the increase of hydroxyl groups on the skeleton surface. Hence, the supercritical modification method utilizing hexamethyldisilazane was also introduced to enhance the hydrophobic methyl groups on the aerogel's surface. As a result, the obtained aerogels revealed superhydrophobicity with a contact angle of 155°. Meanwhile, the developed surface modification method did not lead to any significant changes in the pore structure resulting in the superhydrophobic aerogel with a high transparency of 77.2%. The proposed co-precursor approach and supercritical modification method provide a new horizon in the fabrication of highly transparent and superhydrophobic PMSQ aerogels.

  5. Polymer compositions, polymer films and methods and precursors for forming same

    Science.gov (United States)

    Klaehn, John R; Peterson, Eric S; Orme, Christopher J

    2013-09-24

    Stable, high performance polymer compositions including polybenzimidazole (PBI) and a melamine-formaldehyde polymer, such as methylated, poly(melamine-co-formaldehyde), for forming structures such as films, fibers and bulky structures. The polymer compositions may be formed by combining polybenzimidazole with the melamine-formaldehyde polymer to form a precursor. The polybenzimidazole may be reacted and/or intertwined with the melamine-formaldehyde polymer to form the polymer composition. For example, a stable, free-standing film having a thickness of, for example, between about 5 .mu.m and about 30 .mu.m may be formed from the polymer composition. Such films may be used as gas separation membranes and may be submerged into water for extended periods without crazing and cracking. The polymer composition may also be used as a coating on substrates, such as metal and ceramics, or may be used for spinning fibers. Precursors for forming such polymer compositions are also disclosed.

  6. Effect of precursor supply on structural and morphological characteristics of fe nanomaterials synthesized via chemical vapor condensation method.

    Science.gov (United States)

    Ha, Jong-Keun; Ahn, Hyo-Jun; Kim, Ki-Won; Nam, Tae-Hyun; Cho, Kwon-Koo

    2012-01-01

    Various physical, chemical and mechanical methods, such as inert gas condensation, chemical vapor condensation, sol-gel, pulsed wire evaporation, evaporation technique, and mechanical alloying, have been used to synthesize nanoparticles. Among them, chemical vapor condensation (CVC) has the benefit of its applicability to almost all materials because a wide range of precursors are available for large-scale production with a non-agglomerated state. In this work, Fe nanoparticles and nanowires were synthesized by chemical vapor condensation method using iron pentacarbonyl (Fe(CO)5) as the precursor. The effect of processing parameters on the microstructure, size and morphology of Fe nanoparticles and nanowires were studied. In particular, we investigated close correlation of size and morphology of Fe nanoparticles and nanowires with atomic quantity of inflow precursor into the electric furnace as the quantitative analysis. The atomic quantity was calculated by Boyle's ideal gas law. The Fe nanoparticles and nanowires with various diameter and morphology have successfully been synthesized by the chemical vapor condensation method.

  7. Stability-indicating HPLC–DAD methods for determination of two binary mixtures: Rabeprazole sodium–mosapride citrate and rabeprazole sodium–itopride hydrochloride

    Directory of Open Access Journals (Sweden)

    Hamed M. El-Fatatry

    2014-08-01

    Full Text Available Two selective stability-indicating HPLC methods are described for determination of rabeprazole sodium (RZ–mosapride citrate (MR and RZ–itopride hydrochloride (IO mixtures in the presence of their ICH-stress formed degradation products. Separations were achieved on X-Bridge C18 column using two mobile phases: the first for RZ–MR mixture consisted of acetonitrile: 0.025 M KH2PO4 solution: TEA (30:69:1 v/v; pH 7.0; the second for RZ–IO mixture was at ratio of 25:74:1 (v/v; pH 9.25. The detection wavelength was 283 nm. The two methods were validated and validation acceptance criteria were met in all cases. Peak purity testing using contrast angle theory, relative absorbance and log A versus the wavelengths plots were presented. The % recoveries of the intact drugs were between 99.1% and 102.2% with RSD% values less than 1.6%. Application of the proposed HPLC methods indicated that the methods could be adopted to follow the stability of their formulations. Keywords: Rabeprazole sodium, Mosapride citrate, Itopride hydrochloride, Stability-indicating HPLC–DAD, Peak purity

  8. Toxic Cyanobacteria in Svalbard: Chemical Diversity of Microcystins Detected Using a Liquid Chromatography Mass Spectrometry Precursor Ion Screening Method

    Directory of Open Access Journals (Sweden)

    Julia Kleinteich

    2018-04-01

    Full Text Available Cyanobacteria synthesize a large variety of secondary metabolites including toxins. Microcystins (MCs with hepato- and neurotoxic potential are well studied in bloom-forming planktonic species of temperate and tropical regions. Cyanobacterial biofilms thriving in the polar regions have recently emerged as a rich source for cyanobacterial secondary metabolites including previously undescribed congeners of microcystin. However, detection and detailed identification of these compounds is difficult due to unusual sample matrices and structural congeners produced. We here report a time-efficient liquid chromatography-mass spectrometry (LC-MS precursor ion screening method that facilitates microcystin detection and identification. We applied this method to detect six different MC congeners in 8 out of 26 microbial mat samples of the Svalbard Archipelago in the Arctic. The congeners, of which [Asp3, ADMAdda5, Dhb7] MC-LR was most abundant, were similar to those reported in other polar habitats. Microcystins were also determined using an Adda-specific enzyme-linked immunosorbent assay (Adda-ELISA. Nostoc sp. was identified as a putative toxin producer using molecular methods that targeted 16S rRNA genes and genes involved in microcystin production. The mcy genes detected showed highest similarities to other Arctic or Antarctic sequences. The LC-MS precursor ion screening method could be useful for microcystin detection in unusual matrices such as benthic biofilms or lichen.

  9. 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)

  10. Core Power Control of the fast nuclear reactors with estimation of the delayed neutron precursor density using Sliding Mode method

    International Nuclear Information System (INIS)

    Ansarifar, G.R.; Nasrabadi, M.N.; Hassanvand, R.

    2016-01-01

    Highlights: • We present a S.M.C. system based on the S.M.O for control of a fast reactor power. • A S.M.O has been developed to estimate the density of delayed neutron precursor. • The stability analysis has been given by means Lyapunov approach. • The control system is guaranteed to be stable within a large range. • The comparison between S.M.C. and the conventional PID controller has been done. - Abstract: In this paper, a nonlinear controller using sliding mode method which is a robust nonlinear controller is designed to control a fast nuclear reactor. The reactor core is simulated based on the point kinetics equations and one delayed neutron group. Considering the limitations of the delayed neutron precursor density measurement, a sliding mode observer is designed to estimate it and finally a sliding mode control based on the sliding mode observer is presented. The stability analysis is given by means Lyapunov approach, thus the control system is guaranteed to be stable within a large range. Sliding Mode Control (SMC) is one of the robust and nonlinear methods which have several advantages such as robustness against matched external disturbances and parameter uncertainties. The employed method is easy to implement in practical applications and moreover, the sliding mode control exhibits the desired dynamic properties during the entire output-tracking process independent of perturbations. Simulation results are presented to demonstrate the effectiveness of the proposed controller in terms of performance, robustness and stability.

  11. Ferrimagnetism and spin excitation in a Ni–Mn partially inverted spinel prepared using a modified polymeric precursor method

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, Rafael A. [Programa de Pos-Graduação em Ciência e Tecnologia de Materiais (POSMAT), Universidade Estadual Paulista, Faculdade de Ciências, Caixa Postal 473, 17033-360 Bauru, São Paulo (Brazil); Institut des Sciences Chimiques de Rennes – UMR 6226, Université de Rennes 1, F-35042 Rennes (France); Tedesco, Julio C.G.; Birk, Jonas O. [The Niels Bohr Institute, University of Copenhagen, DK-2100 Copenhagen (Denmark); Kalceff, Walter, E-mail: wkalceff@uts.edu.au [School of Physics and Advanced Materials, University of Technology Sydney (UTS), P.O. Box 123, Broadway, NSW 2007 (Australia); Yokaichiya, Fabiano [Laboratório Nacional de Luz Síncrotron (LNLS), Caixa Postal 6192, CEP 13083-970 Campinas, São Paulo (Brazil); Comissao Nacional de Energia Nuclear (CNEN), Instituto de Pesquisas Energeticas e Nucleares (IPEN), Reactor Multiproposito Brasileiro - RMB, Avenida Lineo Prestes 2242, Bloco A, Cidade Universitaria Armando Salles de Oliveira, Sao Paulo (Brazil); Rasmussen, Nina [The Niels Bohr Institute, University of Copenhagen, DK-2100 Copenhagen (Denmark); Peña, Octavio [Institut des Sciences Chimiques de Rennes – UMR 6226, Université de Rennes 1, F-35042 Rennes (France); Henry, Paul F. [European Spallation Source ESS AB, Box 176, 22100 Lund (Sweden); Simeoni, Giovanna G. [Heinz Maier-Leibnitz Zentrum (MLZ) and Physics Department, Technische Universität München, Lichtenbergstr. 1, 85748 Garching (Germany); Bordallo, Heloisa N. [The Niels Bohr Institute, University of Copenhagen, DK-2100 Copenhagen (Denmark); European Spallation Source ESS AB, Box 176, 22100 Lund (Sweden); and others

    2014-07-01

    We demonstrate that a Ni–Mn oxide partially inverted spinel (Ni{sub 1−ν}Mn{sub ν})[Ni{sub ν}Mn{sub 2−ν}]O{sub 4} having inversion degree ν ≈ 0.8 and produced by a modified polymeric precursor method exhibits behaviour previously reported only in monophased samples. The structure of the specimen was determined using Rietveld analysis of X-ray and neutron powder diffraction data, showing that at room temperature the material crystallizes in the Fd3{sup ¯}m space group with a lattice constant a = 8.392 Å. Combining magnetization measurements with neutron powder diffraction, we show that the magnetic structure of this spinel is associated with the interplay between the ferromagnetic and antiferromagnetic lattices which coexist due to the cations' presence on both tetrahedral and octahedral sites. Our analysis of the neutron diffraction data confirms the postulated magnetic structure involving a star-like moment arrangement, arising from competition for the B (octahedral) spinel sites by the Ni and Mn cations. Finally, we show that strong magnetic fluctuations are observed in the inelastic neutron scattering data. - Highlights: • Ni–Mn oxide partially-inverted spinel made by modified polymeric precursor method. • Magnetic measurements showed a ferrimagnetic and a parasitic magnetic transition. • NPD revealed a magnetic structure consistent with a star-like moment arrangement. • INS measurements indicated four distinct temperature-dependent magnetic regimes.

  12. Hamming method for solving the delayed neutron precursor concentration for reactivity calculation

    International Nuclear Information System (INIS)

    Díaz, Daniel Suescún; Ospina, Juan Felipe Flórez; Sarasty, Jesús Andrés Rodríguez

    2012-01-01

    Highlights: ► We present a new formulation to calculate the reactivity using the Hamming method. ► This method shows better accuracy than existing methods for reactivity calculation. ► The reactivity is calculated without limitation of the nuclear power form. ► The method can be implemented in reactivity meters with time step of up to 0.1 s. - Abstract: We propose a new method for numerically solving the inverse point kinetic equation for a nuclear reactor using the Hamming method, without requiring the nuclear power history and without using the Laplace transform. This new method converges with accuracy of order h 5 , where h is the step in the computation time. The procedure is validated for different forms of the nuclear power and with different time steps. The results indicate that this method has a better accuracy and lower computational effort compared with other conventional methods that use the nuclear power history.

  13. Nanocrystalline Tin Oxide Nanofibers Deposited by a Novel Focused Electrospinning Method. Application to the Detection of TATP Precursors

    Directory of Open Access Journals (Sweden)

    José Pedro Santos

    2014-12-01

    Full Text Available A new method of depositing tin dioxide nanofibers in order to develop chemical sensors is presented. It involves an electrospinning process with in-plane electrostatic focusing over micromechanized substrates. It is a fast and reproducible method. After an annealing process, which can be performed by the substrate heaters, it is observed that the fibers are intertwined forming porous networks that are randomly distributed on the substrate. The fiber diameters oscillate from 100 nm to 200 nm and fiber lengths reach several tens of microns. Each fiber has a polycrystalline structure with multiple nano-grains. The sensors have been tested for the detection of acetone and hydrogen peroxide (precursors of the explosive triacetone triperoxide, TATP in air in the ppm range. High and fast responses to these gases have been obtained.

  14. Nanocrystalline tin oxide nanofibers deposited by a novel focused electrospinning method. Application to the detection of TATP precursors.

    Science.gov (United States)

    Santos, José Pedro; Fernández, Maria Jesús; Fontecha, José Luis; Matatagui, Daniel; Sayago, Isabel; Horrillo, Maria Carmen; Gracia, Isabel

    2014-12-16

    A new method of depositing tin dioxide nanofibers in order to develop chemical sensors is presented. It involves an electrospinning process with in-plane electrostatic focusing over micromechanized substrates. It is a fast and reproducible method. After an annealing process, which can be performed by the substrate heaters, it is observed that the fibers are intertwined forming porous networks that are randomly distributed on the substrate. The fiber diameters oscillate from 100 nm to 200 nm and fiber lengths reach several tens of microns. Each fiber has a polycrystalline structure with multiple nano-grains. The sensors have been tested for the detection of acetone and hydrogen peroxide (precursors of the explosive triacetone triperoxide, TATP) in air in the ppm range. High and fast responses to these gases have been obtained.

  15. Effect of the Precursor Solution Concentration of CuI Thin Film Deposited By Spin Coating Method

    International Nuclear Information System (INIS)

    Nur Amalina Muhmmad; Atiq, A.M.; Rusop, M.

    2011-01-01

    Copper (I) Iodide is a p-type semiconductor with bandgap of 3.1 eV. It is water insoluble solid with three crystalline phases α, β, γ. In this research, the effect of precursor concentration of CuI thin film deposited by spin coating method was studied. The wide band gap p type semiconductor CuI thin film was prepared by mixing the CuI powder (ALDRICH, 98 %) with 50 ml of acetonitrile as a solvent. The CuI concentration varies from 0.025 M to 0.5 M. The speed for spin coating is 1000 rpm for 60 seconds. After the deposition the CuI thin films were annealed at 150 degree Celsius. The electrical and optical properties were characterized by current-voltage (I-V) measurement using Solar Simulator (Bukoh Keiki EP-2000) and ultraviolet visible- near infrared (UV-VIS-NIR) measurement (Jasco V-670). The result shows the CuI thin film properties strongly depends on its precursor concentration. Thickness between 33.65 nm - 441.25 nm was obtained as the concentration increases. The increment of thickness affects the electrical properties which is the resistivity and conductivity of CuI thin film. For optical properties, the transmittance decreases with high concentration as high amount of CuI particle were observed in the thin films. From the transmittance, the absorption coefficient and optical band gap of CuI was determined using Taucs plot. (author)

  16. 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...

  17. 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...

  18. 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...

  19. ORIONR: A simple and effective method for systemic analysis of clinical events and precursors occurring in hospital practice

    International Nuclear Information System (INIS)

    Debouck, F.; Petit, H.; Ravinet, L.; Rieger, E.; Noel, G.

    2012-01-01

    Purpose. - Morbi-mortality review is now recommended by the French Health Authority (Haute Autorite de sante [HAS]) in all hospital settings. It could be completed by Comites de retour d'experience (CREX), making systemic analysis of event precursors which may potentially result in medical damage. As commonly captured by their current practice, medical teams may not favour systemic analysis of events occurring in their setting. They require an easy-to-use method, more or less intuitive and easy-to-learn. It is the reason why ORION R has been set up. Methods. - ORION R is based on experience acquired in aeronautics which is the main precursor in risk management since aircraft crashes are considered as unacceptable even though the mortality from aircraft crashes is extremely low compared to the mortality from medical errors in hospital settings. The systemic analysis is divided in six steps: (i) collecting data, (ii) rebuilding the chronology of facts, (iii) identifying the gaps, (iv) identifying contributing and influential factors, (v) proposing actions to put in place, (vi) writing the analysis report. When identifying contributing and influential factors, four kinds of factors favouring the event are considered: technical domain, working environment, organisation and procedures, human factors. Although they are essentials, human factors are not always considered correctly. The systemic analysis is done by a pilot, chosen among people trained to use the method, querying information from all categories of people acting in the setting. Results. - ORION R is now used in more than 400 French hospital settings for systemic analysis of either morbi-mortality cases or event precursors. It is used, in particular, in 145 radiotherapy centres for supporting CREX. Conclusion. - As very simple to use and quasi-intuitive, ORION R is an asset to reach the objectives defined by HAS: to set up effective morbi-mortality reviews (RMM) and CREX for improving the quality of care in

  20. [ORION®: a simple and effective method for systemic analysis of clinical events and precursors occurring in hospital practice].

    Science.gov (United States)

    Debouck, F; Rieger, E; Petit, H; Noël, G; Ravinet, L

    2012-05-01

    Morbimortality review is now recommended by the French Health Authority (Haute Autorité de santé [HAS]) in all hospital settings. It could be completed by Comités de retour d'expérience (CREX), making systemic analysis of event precursors which may potentially result in medical damage. As commonly captured by their current practice, medical teams may not favour systemic analysis of events occurring in their setting. They require an easy-to-use method, more or less intuitive and easy-to-learn. It is the reason why ORION(®) has been set up. ORION(®) is based on experience acquired in aeronautics which is the main precursor in risk management since aircraft crashes are considered as unacceptable even though the mortality from aircraft crashes is extremely low compared to the mortality from medical errors in hospital settings. The systemic analysis is divided in six steps: (i) collecting data, (ii) rebuilding the chronology of facts, (iii) identifying the gaps, (iv) identifying contributing and influential factors, (v) proposing actions to put in place, (vi) writing the analysis report. When identifying contributing and influential factors, four kinds of factors favouring the event are considered: technical domain, working environment, organisation and procedures, human factors. Although they are essentials, human factors are not always considered correctly. The systemic analysis is done by a pilot, chosen among people trained to use the method, querying information from all categories of people acting in the setting. ORION(®) is now used in more than 400 French hospital settings for systemic analysis of either morbimortality cases or event precursors. It is used, in particular, in 145 radiotherapy centres for supporting CREX. As very simple to use and quasi-intuitive, ORION(®) is an asset to reach the objectives defined by HAS: to set up effective morbi-mortality reviews (RMM) and CREX for improving the quality of care in hospital settings. By helping the

  1. Electrospray ionization mass spectrometric method for the determination of cannabinoid precursors

    DEFF Research Database (Denmark)

    Hansen, H.H.; Hansen, S.H.; Bøjrnsdottir, I.

    1999-01-01

    electrospray ionization mass spectrometry (ESI-MS). The procedure provides complete positioning of all acyl and alkenyl groups contained in each NAPE species. The calibration curve for standard NAPE was linear over the range 100 fmol-50 pmol (0.1-50 ng) per injection. The lower limit of detection (signal......-to-noise ratio of 3) was 100 fmol, implying that this method is superior to previous methods for the determination of NAPE. These results suggest that this ESI-MS method can be used to identify and quantify NAPE species in mammalian tissues and provide information on the corresponding NAEs to be released from...

  2. Structural and morphological characterization of TiO2-ZrO2 powders obtained by the polymeric precursors method

    International Nuclear Information System (INIS)

    Ribeiro, M.A.; Gama, L.; Bispo, A.; Neiva, L.S.; Bernardi, M.I.B.; Kiminami, R.H.G.A.

    2010-01-01

    This work aims to characterize the structure and morphology of TiO 2 -ZrO 2 powders obtained by polymeric precursor method. For this we studied the following compositions: 0.25, 0.5 and 0.75 moles of Zr and calcined at 800 deg C for one hour. The powders obtained were characterized by XRD, SEM and nitrogen adsorption (BET). The analysis of X-ray diffraction showed that the powders had a phase of TiO 2 in the anatase form and a tetragonal phase of ZrO 2 . The crystallite size was between 8, 13 and 11 nm respectively. The analysis of scanning electron microscopy showed the growth of ZrO 2 nanoparticles and that these comprise spherical agglomerates of less than 100 nm. Particle size determined by the BET ranging 28.1-29.5 nm, showing thereby the character of nanosized powders. (author)

  3. Effect of the calcining temperature on the porosity of the titanium dioxide powders obtained by Polymeric Precursor Method

    International Nuclear Information System (INIS)

    Silva, D.W.; Granado, S.R.; Ciola, R.A.; Cavalheiro, A.A.

    2011-01-01

    Ceramics materials obtained by Polymeric Precursor Method exhibit mechanisms of the pore formation and elimination dependents on the decomposition kinetics of the residual organic matter of the polyester. The mechanism of pore elimination seems to occur by disrupting of the wall among the pores because it leads to the consequent pore coalescence and increasing in pore volume, which posses higher pore diameters. In this case, it was observed that the porosity decreasing occurs by pore wall moving after that the residual organic matter is eliminated from the pore inside. The pore diameter associated to the highest volume desorption occurred for the material obtained after calcining at 450°C is approximately 1,7 nm, what seems to be related to the amorphous carbon accumulated inside the pores, once that the pore volume decreases more effectively for the material obtained by calcining at 550°C, making the maximum volume situates at 2,0 nm. (author)

  4. Extração de ferro de esmectita brasileira com emprego do método ditionito-citrato-bicarbonato Iron extraction from Brazilian smectite by dithionite-citrate-bicarbonate method

    Directory of Open Access Journals (Sweden)

    Sidnei Quezada M. Leite

    2000-06-01

    Full Text Available A natural clay from Campina Grande region (Paraíba, Brazil, with 8.57% of Fe2O3, was used to study the most appropriate condition to carry out the iron extraction, without altering the clay structure in a significant way. Samples were treated with the Dithionite-Citrate-Bicarbonate method (DCB for 30 and 120 minutes (pH=9.1, and also with citric acid (pH=1.8; time=15min, at 75°C. Conductivity measurements, X-ray fluorescence, X-ray diffraction, energy-dispersive spectrometry, electron-diffraction with transmission electron microscopy and textural evaluation by nitrogen adsorption were done. The treatment in a basic medium was more selective for iron removal than in acid condition. The time of 30 minutes, with 1.6 g Na2S2O4/10 g clay, was the best condition for the iron extraction.

  5. Synthesis of Nanoscale Lithium-Ion Battery Cathode Materials Using a Porous Polymer Precursor Method

    KAUST Repository

    Deshazer, H.D.

    2011-01-01

    Fine particles of metal oxides with carefully controlled compositions can be easily prepared by the thermal decomposition of porous polymers, such as cellulose, into which solutions containing salts of the desired cations have been dissolved. This is a simple and versatile method that can be used to produce a wide variety of materials with a range of particle sizes and carefully controlled chemical compositions. Examples of the use of this method to produce fine particles of LiCoO2 and Li(NiMnCo)1/3O2, which are used in the positive electrodes of lithium-ion batteries, are shown. Experiments have demonstrated that materials made using this method can have electrochemical properties comparable to those typically produced by more elaborate procedures. © 2011 The Electrochemical Society.

  6. Synthesis of Nanoscale Lithium-Ion Battery Cathode Materials Using a Porous Polymer Precursor Method

    KAUST Repository

    Deshazer, H.D.; Mantia, F. La; Wessells, C.; Huggins, R.A.; Cui, Y.

    2011-01-01

    (NiMnCo)1/3O2, which are used in the positive electrodes of lithium-ion batteries, are shown. Experiments have demonstrated that materials made using this method can have electrochemical properties comparable to those typically produced by more elaborate

  7. Aerobic method for the synthesis of nearly size-monodisperse bismuth nanoparticles from a redox non-innocent precursor

    Science.gov (United States)

    Winter, H.; Christopher-Allison, E.; Brown, A. L.; Goforth, A. M.

    2018-04-01

    Herein, we report an aerobic synthesis method to produce bismuth nanoparticles (Bi NPs) with average diameters in the range 40-80 nm using commercially available bismuth triiodide (BiI3) as the starting material; the method uses only readily available chemicals and conventional laboratory equipment. Furthermore, size data from replicates of the synthesis under standard reaction conditions indicate that this method is highly reproducible in achieving Bi NP populations with low standard deviations in the mean diameters. We also investigated the mechanism of the reaction, which we determined results from the reduction of a soluble alkylammonium iodobismuthate precursor species formed in situ. Under appropriate concentration conditions of iodobismuthate anion, we demonstrate that burst nucleation of Bi NPs results from reduction of Bi3+ by the coordinated, redox non-innocent iodide ligands when a threshold temperature is exceeded. Finally, we demonstrate phase transfer and silica coating of the Bi NPs, which results in stable aqueous colloids with retention of size, morphology, and colloidal stability. The resultant, high atomic number, hydrophilic Bi NPs prepared using this synthesis method have potential for application in emerging x-ray contrast and x-ray therapeutic applications.

  8. Effect of precursor concentration on the structural and optical properties of ZnO nanorods prepared by hydrothermal method

    International Nuclear Information System (INIS)

    Lestari, Amie; Iwan, S.; Djuhana, Dede; Imawan, Cuk; Harmoko, Adhi; Fauzia, Vivi

    2016-01-01

    Zinc oxide (ZnO) nanorods has attractive properties for nanoscale optoelectronic applications, such as optical sensors, ultraviolet laser diodes, and photodetectors. ZnO nanorods, can be fabricated by simple and low cost chemical approach, such as hydrothermal method. In this method, the morphology, microstructure, optical and electrical properties of ZnO nanorods are highly determined by process parameters such as solvent, deposition time, deposition temperature as well as annealing condition. In this paper we report the fabrication of ZnO nanorods that were grown on transparent conducting indium tin oxide coated glass substrates. Initially, ZnO seed layers were deposited on heated substrates with temperature of 450 °C using ultrasonic spray pyrolysis method with frequency of 1.7 MHz and then grown by hydrothermal method with three different precursor concentrations, namely 0.02 M, 0.06 M, and 0.1 M. The surface morphology and structure were investigated by field emission scanning electron microscope (FESEM) and x-ray diffraction (XRD), while the optical properties were observed by photoluminescence (PL) and and UV VIS reflectance spectroscopy.

  9. Effect of Precursor Concentration of MgO nanostructure by using Sol-Gel Method

    Directory of Open Access Journals (Sweden)

    V.T. Srisuvetha

    2017-04-01

    Full Text Available MgO thin flims have been prepared on substrates by a novel and simple sol-gel method using magnesium nitrate and collusion as starting material.The MgO nano catalyst with good sensor crystallization were obtained after annealing at 100°C Magnesium oxide was prepared by sol-gel method. The method involves the hydrolysis of magnesium alkoxide in the presence of acid or basic catalysts followed by a Oxalic acid reaction. The synthesized solids were characterized by IR spectroscopy X-ray diffraction electron microscopy. Ultraviolet visible absorbance measurement photoluminescence and Raman scattering spectra. X-ray diffraction (XRD characterization showed the formation of smaller particles after sol gel irradiation the structure and morphology of the MgO particles were analyzed byXRD. These articles were used for FTIR spectroscopic measurement and spectra were collected. In EDS we calculated the peak intensity the SEM the images of metal oxide.UV (Ultra Violet refers to adsorption spectroscopy optical properties of assorption, band gap energy.This means if use light in the visible and adjacent ranges.

  10. Structural features and electrochemical properties of nanostructured ZnCo2O4 synthesized by an oxalate precursor method

    International Nuclear Information System (INIS)

    Kang, Wenpei; Feng, Fan; Zhang, Miaomiao; Liu, Shaojie; Shen, Qiang

    2013-01-01

    As a Li-ion battery anode, the active substance with a porous nanostructure can be endowed with a high electrochemical performance because of its porosity and remarkable surface area. In this paper, the thermal decomposition of zinc–cobalt binary oxalate precursors, precipitated from a solvothermal medium of ethanol and water (75/25, v/v) at 100 °C, has been performed to synthesize phase-pure ZnCo 2 O 4 spinels, thoroughly giving porous and rod-like configurations with an average length of a few micrometers. Interestingly, each of the as-obtained porous microrods has been well characterized to consist of ∼35.2-nm single-crystalline nanoparticles with polydisperse interspaces. More interestingly, porous ZnCo 2 O 4 microrods can deliver an initial specific discharge capacity of 1,293.7 mAh g −1 with the coulombic efficiency of 76.8 % at 0.2 A g −1 , reaching a value of 937.3 mAh g −1 over 100 discharge–charge cycles. Even at a high current density of 2.0 A g −1 , the porous ZnCo 2 O 4 nanostructures can still possess a reversible discharge capacity of ∼925.0 mAh g −1 , further assigned to the synergistic effect of Zn- and Co-based oxide components. Anyway, the facile oxalate precursor method can realize the controlling synthesis of porous and rod-like ZnCo 2 O 4 nanostructures with a high electrochemical performance

  11. Effects of heating atmosphere on formation of crystalline citrate-derived LaAlO3 nanoparticles

    International Nuclear Information System (INIS)

    Yu, Hsuan-Fu; Guo, Yu-Man

    2011-01-01

    Research highlights: → LaAlO 3 can be crystallized at 550 deg. C in an oxygen-enriched atmosphere. → Calcining the citrate precursor in oxygen atmosphere lowers the reaction temperatures to form crystalline LaAlO 3 . → In oxygen atmosphere, pure citrate-derived LaAlO 3 nanoparticles can be produced at 700 deg. C. - Abstract: Crystalline LaAlO 3 nanoparticles were synthesized at relative low temperatures, using a citrate-precursor technique. La(NO 3 ) 3 , Al(NO 3 ) 3 , and C 3 H 4 (OH)(COOH) 3 , in a molar ratio of 1:1:1, were dissolved in deionized water. NH 4 OH was used to adjust the aqueous solution to pH 7. After drying, the citrate precursors were charred at 350 deg. C, followed by calcination at different temperatures, in air or oxygen atmosphere. The thermochemical properties of the resultant particles were analyzed using thermogravimetric and differential thermal analysis, X-ray diffractometry, infrared spectroscopy, scanning electron microscopy, and transmission electron microscopy. Effects of calcination temperature and heating atmosphere on the formation of crystalline LaAlO 3 nanoparticles were investigated. In O 2 atmosphere, clacining the citrate-derived charred solid precursor at 700 deg. C for 3 h can decompose all intermediates to produce pure LaAlO 3 nanoparticles (particle sizes ≤ 100 nm) with an average crystallite size of about 24 nm and possessing high sinterability.

  12. Electrochemical and mass variation behaviour of rhodium oxide electrodes prepared by the polymeric precursor method

    International Nuclear Information System (INIS)

    Santos, M.C.; Oliveira, R.T.S.; Pereira, E.C.; Bulhoes, L.O.S.

    2005-01-01

    This paper describes an investigation of the charging processes of Rh 2 O 3 electrodes in acidic medium using Electrochemical Quartz Crystal Microbalance. The Rh 2 O 3 was prepared by the Pechini method. The microstructural characterization of the rhodium oxide was performed using Scanning Electron Microscopy and the structure was determined by X-ray diffraction. The Rh 2 O 3 oxidizes at potentials higher than 0.8 V. A mass loss of 60 ng was observed during the anodic sweep. The same amount is gained during the cathodic sweep indicating that the process is reversible. From the mass versus charge plots a slope of 8.5 g mol -1 is calculated. Considering a process that involves a two-electron transfer, the oxidation of Rh 2 O 3 to RhO 2 with the loss of a water molecule (18 g mol -1 ) is proposed

  13. 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.

  14. 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.

  15. Synthesis of highly fluorescent hydrophobic carbon dots by hot injection method using Paraplast as precursor

    International Nuclear Information System (INIS)

    Talib, Abou; Pandey, Sunil; Thakur, Mukeshchand; Wu, Hui-Fen

    2015-01-01

    We have reported synthesis of bright blue colored hydrophobic carbon dots (hC-dots) using highly pure blend of polymers called Paraplast. We developed a hot injection method for making nearly monodispersed hC-dots with a diameter in a range: 5–30 nm as confirmed by high resolution transmission electron microscopy (HRTEM). The involvement of various functional groups was confirmed by Fourier transform infra-red (FTIR) spectroscopy. These hC-dots were incubated with breast cancer stem cells in order to check the entry as well as biological imaging. The cells were analyzed using epifluorescent microscopy. hC-dots showed concentration dependent cytotoxicity (LD 50 : 50 mg/ml) and could be used for bioimaging even at lower concentration (0.5 mg/ml). hC-dots were found to be versatile agents for peeping inside the cells which could also be used for delivery of water insoluble chemotherapeutic agents to variety of solid tumors. - Highlights: • Synthesis of hydrophobic carbon dots from polymer based Paraplast • Deep blue color under the influence of UV light • Typical optical properties used for biological imaging • Biological imaging of breast cancer stem cells revealing potential of carbon dots

  16. Methanol and ethanol electroxidation using Pt electrodes prepared by the polymeric precursor method

    Energy Technology Data Exchange (ETDEWEB)

    Freitas, R.G.; Santos, M.C.; Oliveira, R.T.S.; Bulhoes, L.O.S.; Pereira, E.C. [Laboratorio Interdisciplinar de Eletroquimica e Ceramica, Centro Multidisciplinar para o Desenvolvimento de Materiais Ceramicos, Departamento de Quimica. Universidade Federal de Sao Carlos, C.P. 676, CEP 13565-905, Sao Carlos, SP (Brazil)

    2006-07-14

    The results of methanol and ethanol oxidation in acidic medium on Pt electrodes deposited on Ti substrate using the Pechini method are presented. In this route the metallic salts were dissolved in a mixture of ethylene glycol (EG) and citric acid (CA) forming a polyester network, which is painted onto a Ti substrate and then heat treated at 600{sup o}C in order to obtain the metallic Pt thin films. The X-ray diffraction analysis showed the presence of Pt pattern peaks. The presence of the (420) plane in a higher amount compared to bulk Pt was observed and the peak position of the planes (200) and (420) were displaced by approximately -0.3{sup o}. The roughness data presented almost the same values for Ti and Ti/Pt. The electrochemical characterization of the electrodes in 0.1M HClO{sub 4} showed a typical Pt voltammetric profile. Although the voltammetric profiles of Ti/Pt and bulk Pt were the same, the electrocatalytical behavior for methanol oxidation showed an enhancement of the oxidation current density peak, which increased by 170% compared to bulk platinum. Although, the current density peak for ethanol oxidation on Ti/Pt is smaller than for Pt, it began at 0.11V less positive than the same process on bulk Pt. The chronoamperometric experiments for methanol and ethanol oxidation on Ti/Pt increased by almost 934% and 440%, respectively, compared with Pt bulk. (author)

  17. Methanol and ethanol electroxidation using Pt electrodes prepared by the polymeric precursor method

    Science.gov (United States)

    Freitas, R. G.; Santos, M. C.; Oliveira, R. T. S.; Bulhões, L. O. S.; Pereira, E. C.

    The results of methanol and ethanol oxidation in acidic medium on Pt electrodes deposited on Ti substrate using the Pechini method are presented. In this route the metallic salts were dissolved in a mixture of ethylene glycol (EG) and citric acid (CA) forming a polyester network, which is painted onto a Ti substrate and then heat treated at 600 °C in order to obtain the metallic Pt thin films. The X-ray diffraction analysis showed the presence of Pt pattern peaks. The presence of the (4 2 0) plane in a higher amount compared to bulk Pt was observed and the peak position of the planes (2 0 0) and (4 2 0) were displaced by approximately -0.3°. The roughness data presented almost the same values for Ti and Ti/Pt. The electrochemical characterization of the electrodes in 0.1 M HClO 4 showed a typical Pt voltammetric profile. Although the voltammetric profiles of Ti/Pt and bulk Pt were the same, the electrocatalytical behavior for methanol oxidation showed an enhancement of the oxidation current density peak, which increased by 170% compared to bulk platinum. Although, the current density peak for ethanol oxidation on Ti/Pt is smaller than for Pt, it began at 0.11 V less positive than the same process on bulk Pt. The chronoamperometric experiments for methanol and ethanol oxidation on Ti/Pt increased by almost 934% and 440%, respectively, compared with Pt bulk.

  18. Synthesis of Barium Titanate from Titanyl Acylate Precursor by Sol-precipitate Method

    International Nuclear Information System (INIS)

    Thandar Win; Kyaw Naing; Khin Mar Tun

    2008-03-01

    Nanometersize barium titanates (BaTiO3:BT) powders can be obtained by sol-precipitate method in the presence of polyoxyethylene (20) sorbiton monooleate (Tween-80) as a polymeric surface modifier in a strong alkaline solution (pH > 13). FT-IR, TG/DTA, SEM and XRD were used to investigate the effects of the surfactant influence on the morphology of the obtained BaTiO3 powders. With adding surfactant, a slower rate of hydrolyzation is observed and the rate of condensation is slower. The addition of Tween-80 surfactant in general leads to the formation of smaller particle size of BaTi)3 (70-100 nm). Without adding surfactant, larger particle size of BaTiO3 (100-200 nm) was obtained. The nanometersize BaTiO3 powders were readily sintered at 1000-1200C. Raman-active modes of tetragonal phase BT were detected from Raman spectra of BaTiO3 between 800 0 C to 1200 0 C.

  19. Synthesis of highly fluorescent hydrophobic carbon dots by hot injection method using Paraplast as precursor

    Energy Technology Data Exchange (ETDEWEB)

    Talib, Abou [Doctoral Degree Program in Marine Biotechnology, National Sun Yat-Sen University, Kaohsiung 80424, Taiwan (China); Pandey, Sunil [Department of Chemistry, National Sun Yat-Sen University, 70, Lien-Hai Road, Kaohsiung 80424, Taiwan (China); Center for Nanoscience and Nanotechnology, National Sun Yat-Sen University, 70, Lien-Hai Road, Kaohsiung 80424, Taiwan (China); Thakur, Mukeshchand [Department of Chemistry, National Sun Yat-Sen University, 70, Lien-Hai Road, Kaohsiung 80424, Taiwan (China); Wu, Hui-Fen, E-mail: hui@faculty.nsysu.edu.tw [Department of Chemistry, National Sun Yat-Sen University, 70, Lien-Hai Road, Kaohsiung 80424, Taiwan (China); Center for Nanoscience and Nanotechnology, National Sun Yat-Sen University, 70, Lien-Hai Road, Kaohsiung 80424, Taiwan (China); Doctoral Degree Program in Marine Biotechnology, National Sun Yat-Sen University, Kaohsiung 80424, Taiwan (China); School of Pharmacy, College of Pharmacy, Kaohsiung Medical University, Kaohsiung 800, Taiwan (China); Institute of Medical Science and Technology, National Sun Yat-Sen University, Kaohsiung, 80424, Taiwan (China)

    2015-03-01

    We have reported synthesis of bright blue colored hydrophobic carbon dots (hC-dots) using highly pure blend of polymers called Paraplast. We developed a hot injection method for making nearly monodispersed hC-dots with a diameter in a range: 5–30 nm as confirmed by high resolution transmission electron microscopy (HRTEM). The involvement of various functional groups was confirmed by Fourier transform infra-red (FTIR) spectroscopy. These hC-dots were incubated with breast cancer stem cells in order to check the entry as well as biological imaging. The cells were analyzed using epifluorescent microscopy. hC-dots showed concentration dependent cytotoxicity (LD{sub 50}: 50 mg/ml) and could be used for bioimaging even at lower concentration (0.5 mg/ml). hC-dots were found to be versatile agents for peeping inside the cells which could also be used for delivery of water insoluble chemotherapeutic agents to variety of solid tumors. - Highlights: • Synthesis of hydrophobic carbon dots from polymer based Paraplast • Deep blue color under the influence of UV light • Typical optical properties used for biological imaging • Biological imaging of breast cancer stem cells revealing potential of carbon dots.

  20. Phase pure synthesis of BiFeO3 nanopowders using diverse precursor via co-precipitation method

    International Nuclear Information System (INIS)

    Shami, M. Yasin; Awan, M.S.; Anis-ur-Rehman, M.

    2011-01-01

    Highlights: → Synthesized phase pure BiFeO 3 using diverse precursor by co-precipitation method. → Optimized synthesis and processing parameters. → Thermal behavior, structure and microstructure were analyzed. → Resistivity vs temperature and dielectric constant vs frequency were measured. → Multiferroicity at room temperature was confirmed by M-H and P-E loops. - Abstract: Amorphous powder of BiFeO 3 (BFO) was synthesized at low-temperature (80 deg. C) by co-precipitation method. Optimal synthesis conditions for phase pure BFO were obtained. Powders were calcined in the temperature range from 400 to 600 deg. C for 1 h. Iso-statically pressed powder was sintered at 500 deg. C for 2 h. Differential scanning calorimetric thermo-gram guided for phase transition, crystallization and melting temperatures. X-ray diffraction confirmed the amorphous nature of as synthesized powder and phase formation of calcined powders. Calcination at temperature ≥400 deg. C resulted in nano crystalline powders with perovskite structure. Average crystallite size increased with the increase in calcination temperature. Scanning electron microscopic studies revealed dense granular microstructure of the sintered samples. The sintered samples exhibited high dc resistivity at room temperature which decreased with the increase in temperature. Dielectric constant, dielectric loss tangent and ac conductivity measurements were carried out in the frequency range (10 Hz to 2 MHz). The samples responded weak electric and magnetic polarization at room temperature with unsaturated and hysteresis free loops, respectively.

  1. 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 ...

  2. 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...

  3. 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

  4. 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...

  5. Ethanol electrooxidation using Ti/(RuO2)(x) Pt(1-x) electrodes prepared by the polymeric precursor method

    Energy Technology Data Exchange (ETDEWEB)

    Freitas, R.G.; Marchesi, L.F.Q.P.; Forim, M.R.; Pereira, E.C. [Departamento de Quimica, Universidade Federal de Sao Carlos, Sao Carlos, SP (Brazil); Bulhoes, L.O.S [CENIP, Centro Universitario Central Paulista, Sao Carlos, SP (Brazil); Santos, M.C. [LEMN, Centro de Ciencias Naturais e Humanas, Universidade Federal do ABC, Santo Andre, SP (Brazil); Oliveira, R.T.S., E-mail: robson@icbn.uftm.edu.br [Instituto de Ciencias Biologicas e Naturais, Universidade Federal do Triangulo Mineiro, Uberaba, MG (Brazil)

    2011-09-15

    This work describes a detailed study of the ethanol electrooxidation on Ti/(RuO{sub 2}){sub (x)}Pt{sub (1-x)} electrodes using several compositions prepared by the polymeric precursor method. The results obtained using cyclic voltammetry and chronoamperometry showed that the best composition of Ti/(RuO{sub 2}){sub (x)}Pt{sub (1-x)} electrodes for CO and ethanol oxidation processes is Ti/(RuO{sub 2}){sub 0.50}Pt{sub 0.50}. On this electrode composition the onset of CO and the ethanol oxidation occurred at 380 mV and 220 mV more negative than on Ti/Pt, respectively. Besides, there was an increase of 2.5-fold in the current density for ethanol electrooxidation under constant potential polarization. The Ti/(RuO{sub 2}){sub 0.50}Pt{sub 0.50}. electrodes produced lower amount of acetic acid compared to Ti/Pt and polycrystalline Pt electrodes using in situ HPLC spectrometric analysis. Also, a non common product from ethanol oxidation could be observed on higher RuO{sub 2} loads: ethyl acetate. Finally, the impedance data showed that Ti/(RuO{sub 2}){sub 0.50}Pt{sub 0.50}. electrode composition had the smallest charge transfer resistance for ethanol oxidation among those compositions investigated. (author)

  6. 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

  7. 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.

  8. Does adding metformin to clomifene citrate lead to higher pregnancy rates in a subset of women with polycystic ovary syndrome?

    OpenAIRE

    Moll, E.; Korevaar, J.C.; Bossuyt, P.M.M.; van der Veen, F.

    2008-01-01

    BACKGROUND An RCT among newly diagnosed, therapy naive women with polycystic ovary syndrome (PCOS) showed no significant differences in ovulation rate, ongoing pregnancy rate or spontaneous abortion rate in favour of clomifene citrate plus metformin compared with clomifene citrate. We wanted to assess whether there are specific subgroups of women with PCOS in whom clomifene citrate plus metformin leads to higher pregnancy rates. METHODS Subgroup analysis based on clinical and biochemical para...

  9. An efficient sodium citrate-promoted synthetic method for the preparation of AuNPs@mesoSiO2 for surface enhanced Raman spectroscopy in the detection of diluted blood

    Directory of Open Access Journals (Sweden)

    Yun Zou

    2017-12-01

    Full Text Available We report on a novel, green, and efficient organically synthetic method for the preparation of gold nanoparticles embedded in mesoporous silica (AuNPs@mesoSiO2. AuNPs@mesoSiO2 prepared by one-pot synthesis method using sodium citrate as the key reactant was applied for surface enhanced Raman spectroscopy (SERS application in the analysis of diluted blood traces. The synthesized nanoparticles are of high quality, as characterized by use of X-ray diffraction, scanning electron microscopy and transmission electron microscopy. They exhibit high surface areas (170.18–883 m2/g and significant SERS enhancement. Detection of diluted blood (v/v, 1:50 traces through AuNPs@mesoSiO2 enhanced SERS is demonstrated, which has not been studied in previous literature. The combination of the SERS and AuNPs@mesoSiO2 would be a valuable tool for forensic investigation. Keywords: Gold nanoparticles, Mesoporous materials, Synthesis, SERS, Blood trace

  10. Low-temperature SiON films deposited by plasma-enhanced atomic layer deposition method using activated silicon precursor

    Energy Technology Data Exchange (ETDEWEB)

    Suh, Sungin; Kim, Jun-Rae; Kim, Seongkyung; Hwang, Cheol Seong; Kim, Hyeong Joon, E-mail: thinfilm@snu.ac.kr [Department of Materials Science and Engineering with Inter-University Semiconductor Research Center (ISRC), Seoul National University, 599 Gwanak-ro, Gwanak-gu, Seoul 08826 (Korea, Republic of); Ryu, Seung Wook, E-mail: tazryu78@gmail.com [Department of Electrical Engineering, Stanford University, Stanford, California 94305-2311 (United States); Cho, Seongjae [Department of Electronic Engineering and New Technology Component & Material Research Center (NCMRC), Gachon University, Seongnam-si, Gyeonggi-do 13120 (Korea, Republic of)

    2016-01-15

    It has not been an easy task to deposit SiN at low temperature by conventional plasma-enhanced atomic layer deposition (PE-ALD) since Si organic precursors generally have high activation energy for adsorption of the Si atoms on the Si-N networks. In this work, in order to achieve successful deposition of SiN film at low temperature, the plasma processing steps in the PE-ALD have been modified for easier activation of Si precursors. In this modification, the efficiency of chemisorption of Si precursor has been improved by additional plasma steps after purging of the Si precursor. As the result, the SiN films prepared by the modified PE-ALD processes demonstrated higher purity of Si and N atoms with unwanted impurities such as C and O having below 10 at. % and Si-rich films could be formed consequently. Also, a very high step coverage ratio of 97% was obtained. Furthermore, the process-optimized SiN film showed a permissible charge-trapping capability with a wide memory window of 3.1 V when a capacitor structure was fabricated and measured with an insertion of the SiN film as the charge-trap layer. The modified PE-ALD process using the activated Si precursor would be one of the most practical and promising solutions for SiN deposition with lower thermal budget and higher cost-effectiveness.

  11. Effects of copper precursor concentration on the growth of cupric oxide nanorods for photoelectrode using a modified chemical bath deposition method

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Hee-bong [Department of Nano Science and Engineering, High Safety Vehicle Core Technology Research Center, Inje University, Gimhae, Gyeongnam 621-749 (Korea, Republic of); Ryu, Hyukhyun, E-mail: hhryu@inje.ac.kr [Department of Nano Science and Engineering, High Safety Vehicle Core Technology Research Center, Inje University, Gimhae, Gyeongnam 621-749 (Korea, Republic of); Lee, Won-Jae [Department of Materials and Components Engineering, Dong-Eui University, Busan 614-714 (Korea, Republic of)

    2015-01-25

    Highlights: • CuO nanorod photoelectrodes were prepared by modified CBD method. • The CuO nanorods were vertically grown with a high growth rate. • Effects of precursor concentration on the CuO nanorods were investigated. - Abstract: In this study, vertically aligned CuO nanorods were grown using a modified chemical bath deposition method with various copper precursor concentrations. The morphological, structural, optical and photoelectrochemical properties of the synthesized CuO samples were characterized using a field-emission scanning electron microscope, an X-ray diffractometer, a UV–visible spectrometer and a three-electrode potentiostat, respectively. The growth rates of the samples varied from 4.3 to 500 nm/min with the varying precursor concentrations. The vertically well-grown CuO nanorods exhibited one-dimensional growth along the (0 2 0) plane. We obtained a maximum photocurrent density of −1.05 mA/cm{sup 2} at −0.6 V (vs. SCE) from the CuO nanorod photoelectrode grown using the 10 mM copper precursor concentration.

  12. Synthesis of BaTiO{sub 3} and SrTiO{sub 3} by microwave assisted hydrothermal method (MAH) using anatase as titanium precursor

    Energy Technology Data Exchange (ETDEWEB)

    Magalhães, Renata da Silva; Macedo Junior, Wagner Dias; Souza, Agda Eunice de; Teixeira, Silvio Rainho, E-mail: R.S.Magalhaes@hotmail.com [Universidade Estadual Paulista Julio de Mesquita Filho (FCT/UNESP), Presidente Prudente, SP (Brazil); Li, Maximo Siu [Universidade de Sao Paulo (USP), São Carlos, SP (Brazil). Instituto de Física; Longo, Elson [Universidade Estadual Paulista Julio de Mesquita Filho (UNESP), Araraquara, SP (Brazil). Instituto de Química

    2016-07-01

    Full text: Strontium and barium titanates (SrTiO{sub 3} (ST) and BaTiO{sub 3} (BT)) in their crystalline form belong to the perovskite (ABO{sub 3}) class. Both display a semiconductor behavior with many interesting properties. The method of synthesis employed and different precursors may influence the morphology and properties of ceramic materials [1,2]. Barium (BT) and strontium (St) titanates were produced using the Microwave Assisted Hydrothermal Method (MAH), different concentrations (1,3 and 6 molL{sup -1}) of mineralizer (KOH) and a different titanium precursor: a complex anatase-hydrogen peroxide. Barium and strontium chloride were used as the other metal precursors. The resulting material were characterized by different techniques such as: X-ray diffraction (XRD), Micro-Raman Spectroscopy (MR), UV-Vis, Scanning Electron microscopy (SEM) and finally their photoluminescent emissions (FL) were recorded at room temperature. The results show that there were differences in crystallinity, morphology, number of formed phases and photoluminescent emission, among the titanate produced with different concentrations of mineralizer. References: [1] A.E. Souza et al., Order–disorder degree of self-assembled clusters: Influence on photoluminescence emission and morphology of Ba{sub x}Sr{sub 1-x}TiO{sub 3} nanocrystals, Chemical Physics Letters 514 (2011) 301–306. [2] T. M. Mazzo et al., Influence of titanium precursor on photoluminescent emission of micro-cube-shaped CaTiO{sub 3}, Journal of Luminescence 165 (2015). (author)

  13. Synthesis of BaTiO3 and SrTiO3 by microwave assisted hydrothermal method (MAH) using anatase as titanium precursor

    International Nuclear Information System (INIS)

    Magalhães, Renata da Silva; Macedo Junior, Wagner Dias; Souza, Agda Eunice de; Teixeira, Silvio Rainho; Li, Maximo Siu; Longo, Elson

    2016-01-01

    Full text: Strontium and barium titanates (SrTiO 3 (ST) and BaTiO 3 (BT)) in their crystalline form belong to the perovskite (ABO 3 ) class. Both display a semiconductor behavior with many interesting properties. The method of synthesis employed and different precursors may influence the morphology and properties of ceramic materials [1,2]. Barium (BT) and strontium (St) titanates were produced using the Microwave Assisted Hydrothermal Method (MAH), different concentrations (1,3 and 6 molL -1 ) of mineralizer (KOH) and a different titanium precursor: a complex anatase-hydrogen peroxide. Barium and strontium chloride were used as the other metal precursors. The resulting material were characterized by different techniques such as: X-ray diffraction (XRD), Micro-Raman Spectroscopy (MR), UV-Vis, Scanning Electron microscopy (SEM) and finally their photoluminescent emissions (FL) were recorded at room temperature. The results show that there were differences in crystallinity, morphology, number of formed phases and photoluminescent emission, among the titanate produced with different concentrations of mineralizer. References: [1] A.E. Souza et al., Order–disorder degree of self-assembled clusters: Influence on photoluminescence emission and morphology of Ba x Sr 1-x TiO 3 nanocrystals, Chemical Physics Letters 514 (2011) 301–306. [2] T. M. Mazzo et al., Influence of titanium precursor on photoluminescent emission of micro-cube-shaped CaTiO 3 , Journal of Luminescence 165 (2015). (author)

  14. 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.

  15. TiO{sub 2} synthesized by the method of polymeric precursor (Pechini): structure of the intermediate resine; TiO{sub 2} sintetizado por el metodo de precursor polimerico (Pechini): estructura de la resina intermedia

    Energy Technology Data Exchange (ETDEWEB)

    Vargas, M. A.; Granco, Y.; Ochoa, Y.; Ortegon, Y.; Rodriguez Paez, J. E.

    2011-07-01

    In this work, the polymeric precursor method (Pechini method) was used to synthesize titanium dioxide. This process allowed a bigger control on the purity of the oxide and the crystalline phase present in the material. In this case, the principal phase was anatase. The resine obtained in this process was characterized using NMR and IR spectroscopy to determine their structure. With this information we proposed a resine structure model. To finish the process, the resin was thermally treated to obtain TiO{sub 2}. This oxide was characterized using different techniques: ray-X diffraction (RDX) and electron microscopy (TEM and SEM). The results indicated that the TiO{sub 2} anatase phase can be obtained at 450 degree centigrade with a particle size <100nm. (Author) 10 refs.

  16. Thermoset precursor

    International Nuclear Information System (INIS)

    Yamamoto, Y.

    1983-04-01

    This invention pertains to a distinctive thermoset precursor which is prepared by mixing a resin composition (A) which can be hardened by ionizing radiation, and a resin composition (B) which can be hardened by heat but cannot be hardened by, or is resistant to, ionizing radiation, and by coating or impregnating a molding or other substrate with a sheet or film of this mixture and irradiating this with an ionizing radiation. The principal components of composition (A) and (B) can be the following: (1) an acrylate or methacrylate and an epoxy resin and an epoxy resin hardener; (2) an unsaturated polyester resin and epoxy resin and an epoxy resin hardener; (3) a diacrylate or dimethacrylate or polyethylene glycol and an epoxy resin; (4) an epoxy acrylates or epoxy methacrylate obtained by the addition reaction of epoxy resin and acrylic or methacrylic acid

  17. Precursor analyses - The use of deterministic and PSA based methods in the event investigation process at nuclear power plants

    International Nuclear Information System (INIS)

    2004-09-01

    The efficient feedback of operating experience (OE) is a valuable source of information for improving the safety and reliability of nuclear power plants (NPPs). It is therefore essential to collect information on abnormal events from both internal and external sources. Internal operating experience is analysed to obtain a complete understanding of an event and of its safety implications. Corrective or improvement measures may then be developed, prioritized and implemented in the plant if considered appropriate. Information from external events may also be analysed in order to learn lessons from others' experience and prevent similar occurrences at our own plant. The traditional ways of investigating operational events have been predominantly qualitative. In recent years, a PSA-based method called probabilistic precursor event analysis has been developed, used and applied on a significant scale in many places for a number of plants. The method enables a quantitative estimation of the safety significance of operational events to be incorporated. The purpose of this report is to outline a synergistic process that makes more effective use of operating experience event information by combining the insights and knowledge gained from both approaches, traditional deterministic event investigation and PSA-based event analysis. The PSA-based view on operational events and PSA-based event analysis can support the process of operational event analysis at the following stages of the operational event investigation: (1) Initial screening stage. (It introduces an element of quantitative analysis into the selection process. Quantitative analysis of the safety significance of nuclear plant events can be a very useful measure when it comes to selecting internal and external operating experience information for its relevance.) (2) In-depth analysis. (PSA based event evaluation provides a quantitative measure for judging the significance of operational events, contributors to

  18. Effects of ZnO Seed Layers Prepared with Various Precursor Concentrations on Structural and Defect Emission Properties of ZnO Nanorods Grown by Hydrothermal Method

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Soaram; Nam, Giwoong; Leem, Jae-Young; Kim, Yangsoo [Inje University, Gimhae (Korea, Republic of); Kim, Ghun Sik; Yoon, Sung Pil [Korea Institute of Science and Technology, Seoul (Korea, Republic of)

    2013-07-15

    ZnO nanorods were grown by a hydrothermal method on ZnO seed layers that had previously been prepared from solutions containing various precursor concentrations. The effects of the ZnO seed layers prepared with various precursor concentrations on the structural and defect emissions of the ZnO nanorods were investigated by scanning electron microscopy (SEM), X-ray diffraction (XRD), and photoluminescence (PL) spectroscopy. The surface morphology of the ZnO seed layers changed with an increasing precursor concentration, and the diameters and densities of the ZnO nanorods depended on the morphologies of the ZnO seed layers. The ZnO seed layers prepared with various precursor concentrations affected the residual stress in the nanorods grown on the seed layers, the intensity and full widths at half maximum of the 2-theta angle in the XRD spectra for the nanorods, and the intensity and position of the defect emission peak in deep-level emission (DLE) PL spectra for the ZnO nanorods.

  19. 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)

  20. 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.

  1. [Application of precursor ion scanning method in rapid screening of illegally added phosphodiesterase-5 inhibitors and their unknown derivatives in Chinese traditional patent medicines and health foods].

    Science.gov (United States)

    Sun, Jing; Cao, Ling; Feng, Youlong; Tan, Li

    2014-11-01

    The compounds with similar structure often have similar pharmacological activities. So it is a trend for illegal addition that new derivatives of effective drugs are synthesized to avoid the statutory test. This bring challenges to crack down on illegal addition behavior, however, modified derivatives usually have similar product ions, which allow for precursor ion scanning. In this work, precursor ion scanning mode of a triple quadrupole mass spectrometer was first applied to screen illegally added drugs in complex matrix such as Chinese traditional patent medicines and healthy foods. Phosphodiesterase-5 inhibitors were used as experimental examples. Through the analysis of the structure and mass spectrum characteristics of the compounds, phosphodiesterase-5 inhibitors were classified, and their common product ions were screened by full scan of product ions of typical compounds. Then high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method with precursor ion scanning mode was established based on the optimization of MS parameters. The effect of mass parameters and the choice of fragment ions were also studied. The method was applied to determine actual samples and further refined. The results demonstrated that this method can meet the need of rapid screening of unknown derivatives of phosphodiesterase-5 inhibitors in complex matrix, and prevent unknown derivatives undetected. This method shows advantages in sensitivity, specificity and efficiency, and is worth to be further investigated.

  2. Effect of the calcining temperature on the porosity of the titanium dioxide powders obtained by Polymeric Precursor Method; Efeito da temperatura de calcinacao na porosidade de pos de dioxido de titanio obtidos pelo Metodo dos Precursores Polimericos

    Energy Technology Data Exchange (ETDEWEB)

    Silva, D.W.; Granado, S.R.; Ciola, R.A.; Cavalheiro, A.A., E-mail: douglas_levis@hotmail.com [Universidade Estadual de Mato Grosso do Sul (CPTREN/UEMS), Navirai, MS (Brazil). Centro de Pesquisas Tecnologicas em Recursos Naturais

    2011-07-01

    Ceramics materials obtained by Polymeric Precursor Method exhibit mechanisms of the pore formation and elimination dependents on the decomposition kinetics of the residual organic matter of the polyester. The mechanism of pore elimination seems to occur by disrupting of the wall among the pores because it leads to the consequent pore coalescence and increasing in pore volume, which posses higher pore diameters. In this case, it was observed that the porosity decreasing occurs by pore wall moving after that the residual organic matter is eliminated from the pore inside. The pore diameter associated to the highest volume desorption occurred for the material obtained after calcining at 450°C is approximately 1,7 nm, what seems to be related to the amorphous carbon accumulated inside the pores, once that the pore volume decreases more effectively for the material obtained by calcining at 550°C, making the maximum volume situates at 2,0 nm. (author)

  3. The influence of metronidazole resistance on the efficacy of ranitidine bismuth citrate triple therapy regimens for Helicobacter pylori infection

    NARCIS (Netherlands)

    Van der Wouden, EJ; Thijs, JC; Van Zwet, AA; Kooy, A; Kleibeuker, JH

    Aim: To assess the influence of metronidazole resistance on the efficacy of ranitidine bismuth citrate-based triple therapy regimens in two consecutive studies. Methods: In the first study, patients with a culture-proven Helicobacter pylori infection were treated with ranitidine bismuth citrate 400

  4. 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...

  5. Effects of precursor on the morphology and size of ZrO2 nanoparticles, synthesized by sol-gel method in non-aqueous medium

    International Nuclear Information System (INIS)

    Siddiqui, Mohammed Rafiq Hussain; Al-Wassil, Abdulaziz Ibrahim; Mahfouz, Refaat Mohamad; Al-Otaibi, Abdullah Mohmmed

    2012-01-01

    Pure zirconium oxide (ZrO 2 ) nanoparticles with diameters 10-25 nm were synthesized from ZrOCl 2 .8H 2 O and Zr(SO 4 )2.H 2 O with benzyl alcohol as non-aqueous solvent medium using sol-gel method. Sodium lauryl sulfate was added as surfactants to control the particle size. The synthesized ZrO 2 nanoparticles have a mixture of tetragonal and monoclinic structure. The XRD showed the purity of obtained ZrO 2 nanoparticles with tetragonal and monoclinic phase and the crystallite size for ZrOCl 2 .8H 2 O precursor was estimated to be 18.1 nm and that from Zr(SO 4 )2.H 2 O was 9.7 nm. The transmission electron microscopy and scanning electron microscopic studies also shows different sizes of nanoparticles and different morphology depending on the precursor used for the synthesis of ZrO 2 nanoparticles. (author)

  6. 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...

  7. 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.

  8. 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

  9. 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)

  10. 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...

  11. A 3D nodal mixed dual method for nuclear reactor kinetics with improved quasistatic model and a semi-implicit scheme to solve the precursor equations

    International Nuclear Information System (INIS)

    Dahmani, M.; Baudron, A.M.; Lautard, J.J.; Erradi, L.

    2001-01-01

    The mixed dual nodal method MINOS is used to solve the reactor kinetics equations with improved quasistatic IQS model and the θ method is used to solve the precursor equations. The speed of calculation which is the main advantage of the MINOS method and the possibility to use the large time step for shape flux calculation permitted by the IQS method, allow us to reduce considerably the computing time. The IQS/MINOS method is implemented in CRONOS 3D reactor code. Numerical tests on different transient benchmarks show that the results obtained with the IQS/MINOS method and the direct numerical method used to solve the kinetics equations, are very close and the total computing time is largely reduced

  12. MID Max: LC–MS/MS Method for Measuring the Precursor and Product Mass Isotopomer Distributions of Metabolic Intermediates and Cofactors for Metabolic Flux Analysis Applications

    DEFF Research Database (Denmark)

    McCloskey, Douglas; Young, Jamey D.; Xu, Sibei

    2016-01-01

    The analytical challenges to acquire accurate isotopic data of intracellular metabolic intermediates for stationary, nonstationary, and dynamic metabolic flux analysis (MFA) are numerous. This work presents MID Max, a novel LC–MS/MS workflow, acquisition, and isotopomer deconvolution method for MFA...... that takes advantage of additional scan types that maximizes the number of mass isotopomer distributions (MIDs) that can be acquired in a given experiment. The analytical method was found to measure the MIDs of 97 metabolites, corresponding to 74 unique metabolite-fragment pairs (32 precursor spectra and 42...

  13. Polymeric precursors method for obtaining pigments based on Inorganic oxides of chromium and iron deposited on TiO2

    International Nuclear Information System (INIS)

    Silva, Everlania M. da; Galvao, Sheila B.; Paskocimas, C.A.

    2011-01-01

    The case study was the use of chromium oxides and iron, as a precursor in the synthesis of inorganic pigments. The synthesis was based on the dissolution of citric acid as a complexing agent, addition of metal oxides, such as ion chromophores; polymerization with ethylene glycol and doping with titanium oxide. Going through pre-calcination, breakdown, calcination at different temperatures (700, 900 and 1100 deg C resulting in pigments: green for pigment and chromium deposited on TiO2, orange for iron on TiO2. The thermal analysis (TG and DTA), evaluated their thermal decompositions, the XRD revealed the formation of crystalline phases such as iron titanate and chrome titanate; SEM showed the formation of hexagonal particles for both oxides. Under the different analysis, one can see the potential stability of pigments and powders, can be proposed its use as pigments in polymers. (author)

  14. Recycling of LiCo0.59Mn0.26Ni0.15O2 cathodic material from spent Li-ion batteries by the method of the citrate gel combustion

    Directory of Open Access Journals (Sweden)

    Senćanski Jelena V.

    2017-01-01

    Full Text Available The Li-ion batteries are the main power source for the high technology devices, such as mobile phones and electric vehicles. Because of that, the number of spent Li-ion batteries significantly increases. Today, the number of active mobile phones crossed 7.19 billion. It is estimated that the mass of the spent lithium ion batteries in China will exceed 500,000 t by 2020. The trouble is in the ingredients of these batteries. They contain Li, Co, Mn, Ni, Cu, Al and toxic and flammable electrolytes which have a harmful affection to the environment. Because of that, the recycling procedure attracts raising attention of researches. Several commercial spent Li-ion batteries were recycled by the relatively fast, economic and simple procedure. The three ways of separating the cathode material from Al collector were examined after the manual dismantling of the components of batteries with the Li(Co–Mn–NiO2 as cathode material. These were: 1. dissolution of the Al collector in the alkali medium, 2. peeling off with N-methylpyrrolidone and 3. thermal decomposition of the adhesive at 700°C. The procedure with the highest yield was the one with the dissolution in alkali medium. The chemical analysis of the single batteries'' components (the crust, Al/Cu collector, cathode material were done by the atomic absorption spectrometry. The components, before the analysis, were dissolved. The re-synthesis of the cathode material by the method of the citrate gel combustion was done after the separating the cathode material and dissolving it in the nitric acid. The obtained product was, after annealing, characterized by the methods of X-ray diffraction and Raman spectroscopy. The recycled product was LiCo0.59Mn0.26Ni0.15O2 stoichiometry, with the hexagonal layered structure α-NaFeO2 type. The functionalization of the resynthesized material was examined in the 1 M solution LiClO4 in the propylene carbonate, by galvanostatic charging, with the current density of 0

  15. Influence of aging time of oleate precursor on the magnetic relaxation of cobalt ferrite nanoparticles synthesized by the thermal decomposition method

    International Nuclear Information System (INIS)

    Herrera, Adriana P.; Polo-Corrales, Liliana; Chavez, Ermides; Cabarcas-Bolivar, Jari; Uwakweh, Oswald N.C.; Rinaldi, Carlos

    2013-01-01

    Cobalt ferrite nanoparticles are of interest because of their room temperature coercivity and high magnetic anisotropy constant, which make them attractive in applications such as sensors based on the Brownian relaxation mechanism and probes to determine the mechanical properties of complex fluids at the nanoscale. These nanoparticles can be synthesized with a narrow size distribution by the thermal decomposition of an iron–cobalt oleate precursor in a high boiling point solvent. We studied the influence of aging time of the iron–cobalt oleate precursor on the structure, chemical composition, size, and magnetic relaxation of cobalt ferrite nanoparticles synthesized by the thermal decomposition method. The structure and thermal behavior of the iron–cobalt oleate was studied during the aging process. Infrared spectra indicated a shift in the coordination state of the oleate and iron/cobalt ions from bidentate to bridging coordination. Aging seemed to influence the thermal decomposition of the iron–cobalt oleate as determined from thermogravimmetric analysis and differential scanning calorimetry, where shifts in the temperatures corresponding to decomposition events and a narrowing of the endotherms associated with these events were observed. Aging promoted formation of the spinel crystal structure, as determined from X-ray diffraction, and influenced the nanoparticle magnetic properties, resulting in an increase in blocking temperature and magnetocrystalline anisotropy. Mossbauer spectra also indicated changes in the magnetic properties resulting from aging of the precursor oleate. Although all samples exhibited some degree of Brownian relaxation, as determined from complex susceptibility measurements in a liquid medium, aging of the iron–cobalt oleate precursor resulted in crossing of the in-phase χ′and out-of-phase χ″ components of the complex susceptibility at the frequency of the Brownian magnetic relaxation peak, as expected for nanoparticles

  16. Synthesis by the polymeric precursor method and characterization of undoped and Sn, Cr and V-doped ZrTiO4

    International Nuclear Information System (INIS)

    Rodrigues de Lucena, Poty; Pessoa-Neto, Osmundo Dantas; Garcia dos Santos, Ieda Maria; Souza, Antonio Gouveia; Longo, Elson; Varela, Jose Arana

    2005-01-01

    In this work, zirconium titanate doped with 0.1, 0.2, and 0.4-bar mole% of tin, chromium and vanadium was synthesized by the polymeric precursors method and characterized by thermal analysis (TG/DTA), X-ray diffraction (XRD), nitrogen adsorption and scanning electronic microscopy (SEM). The powder presented two mass losses attributed to the exit of water and to the pyrolysis of the organic material. The surface area reduction observed from 500-bar o C indicates the beginning of the sintering process. All the dopants led to changes in the lattice parameters and to the decrease of both crystallite size and particle size

  17. Microstructural study of Ce1-xGdxO2-δ (x = 0.1 and 0.2) nano crystallized powders synthesized by the polymeric precursor method

    International Nuclear Information System (INIS)

    Cela, B.; Macedo, D.A.; Souza, G.L.; Paskocimas, C.A.; Martinelli, A.E.; Nascimento, R.M.

    2009-01-01

    Gadolinia-doped ceria powders (Ce 1-x Gd x O 2-δ ) were prepared with substitution of 10 and 20% of the dopant element by the polymeric precursor method. This method makes possible the attainment of homogeny powder in molecular level, ideal to application in Solid Oxide Fuel Cell (SOFC) component. In this work, the particulated materials were calcinated in a range from 500 °C to 900 °C and structurally characterized by X-Ray Diffraction (XRD). The sintering behaviors of the compact samples were determined by dilatometric analyses. The results showed the method efficiency to attain monophasic nanopowder with cubic crystalline structure starting at 700 °C. The crystallite average size and crystalline parameter were determined by the Rietveld refinement method. (author)

  18. Multi-development-HPTLC method for quantitation of hyoscyamine, scopolamine and their biosynthetic precursors in selected solanaceae plants grown in natural conditions and as in vitro cultures.

    Science.gov (United States)

    Jaremicz, Zbigniew; Luczkiewicz, Maria; Kisiel, Mariusz; Zárate, Rafael; El Jaber-Vazdekis, Nabil; Migas, Piotr

    2014-01-01

    Hyoscyamine and scopolamine, anti-cholinergic agents widely used in medicine, are typically obtained from plants grown under natural conditions. Since field cultivation entails certain difficulties (changeable weather, pests, etc.), attempts have been made to develop a plant in vitro culture system as an alternative source for the production of these compounds. During experiments to locate the limiting steps in the biotechnological procedure, it is important to monitor not only the levels of the final products but also the changes in the concentration of their precursors. To develop a HPTLC method for the separation and quantitation of the main tropane alkaloids hyoscyamine and scopolamine, their respective direct precursors littorine and anisodamine, and cuscohygrine, a product of a parallel biosynthetic pathway that shares a common precursor (N-methyl-∆(1) -pyrrolium cation) with tropane alkaloids. Using alkaloid extracts from Atropa baetica hairy roots, different TLC chromatographic systems and developing procedures were investigated. Full separation of all compounds was obtained on HPTLC Si60 F254 plates preconditioned with mobile phase vapours (chloroform:methanol:acetone:25% ammonia ratios of 75:15:10:1.8, v/v/v/v). The chromatograms were developed twice (at distances of 4.0 and 3.0 cm) in a Camag twin trough chamber and visualised with Dragendorff's reagent. Densitometric detection (λ = 190 and 520 nm) was used for quantitative analyses of the different plant samples. This method can be recommended for quantitation of hyoscyamine, scopolamine, anisodamine, littorine and cuscohygrine in different plant material (field grown vs. in vitro cultures). Copyright © 2013 John Wiley & Sons, Ltd.

  19. 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

  20. The EM Earthquake Precursor

    Science.gov (United States)

    Jones, K. B., II; Saxton, P. T.

    2013-12-01

    Many attempts have been made to determine a sound forecasting method regarding earthquakes and warn the public in turn. Presently, the animal kingdom leads the precursor list alluding to a transmission related source. By applying the animal-based model to an electromagnetic (EM) wave model, various hypotheses were formed, but the most interesting one required the use of a magnetometer with a differing design and geometry. To date, numerous, high-end magnetometers have been in use in close proximity to fault zones for potential earthquake forecasting; however, something is still amiss. The problem still resides with what exactly is forecastable and the investigating direction of EM. After the 1989 Loma Prieta Earthquake, American earthquake investigators predetermined magnetometer use and a minimum earthquake magnitude necessary for EM detection. This action was set in motion, due to the extensive damage incurred and public outrage concerning earthquake forecasting; however, the magnetometers employed, grounded or buried, are completely subject to static and electric fields and have yet to correlate to an identifiable precursor. Secondly, there is neither a networked array for finding any epicentral locations, nor have there been any attempts to find even one. This methodology needs dismissal, because it is overly complicated, subject to continuous change, and provides no response time. As for the minimum magnitude threshold, which was set at M5, this is simply higher than what modern technological advances have gained. Detection can now be achieved at approximately M1, which greatly improves forecasting chances. A propagating precursor has now been detected in both the field and laboratory. Field antenna testing conducted outside the NE Texas town of Timpson in February, 2013, detected three strong EM sources along with numerous weaker signals. The antenna had mobility, and observations were noted for recurrence, duration, and frequency response. Next, two

  1. 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.

  2. A single-source solid-precursor method for making eco-friendly doped semiconductor nanoparticles emitting multi-color luminescence.

    Science.gov (United States)

    Manzoor, K; Aditya, V; Vadera, S R; Kumar, N; Kutty, T R N

    2007-02-01

    A novel synthesis method is presented for the preparation of eco-friendly, doped semiconductor nanocrystals encapsulated within oxide-shells, both formed sequentially from a single-source solid-precursor. Highly luminescent ZnS nanoparticles, in situ doped with Cu(+)-Al3+ pairs and encapsulated with ZnO shells are prepared by the thermal decomposition of a solid-precursor compound, zinc sulfato-thiourea-oxyhydroxide, showing layered crystal structure. The precursor compound is prepared by an aqueous wet-chemical reaction involving necessary chemical reagents required for the precipitation, doping and inorganic surface capping of the nanoparticles. The elemental analysis (C, H, N, S, O, Zn), quantitative estimation of different chemical groups (SO4(2-) and NH4(-)) and infrared studies suggested that the precursor compound is formed by the intercalation of thiourea, and/or its derivatives thiocarbamate (CSNH2(-)), dithiocarbamate (CS2NH2(-)), etc., and ammonia into the gallery space of zinc-sulfato-oxyhydroxide corbel where the Zn(II) ions are both in the octahedral as well as tetrahedral coordination in the ratio 3 : 2 and the dopant ions are incorporated within octahedral voids. The powder X-ray diffraction of precursor compound shows high intensity basal reflection corresponding to the large lattice-plane spacing of d = 11.23 angstroms and the Rietveld analysis suggested orthorhombic structure with a = 9.71 angstroms, b = 12.48 angstroms, c = 26.43 angstroms, and beta = 90 degrees. Transmission electron microscopy studies show the presence of micrometer sized acicular monocrystallites with prismatic platy morphology. Controlled thermolysis of the solid-precursor at 70-110 degrees C leads to the collapse of layered structure due to the hydrolysis of interlayer thiourea molecules or its derivatives and the S2- ions liberated thereby reacts with the tetrahedral Zn(II) atoms leading to the precipitation of ZnS nanoparticles at the gallery space. During this process

  3. Effects of precursor on the morphology and size of ZrO{sub 2} nanoparticles, synthesized by sol-gel method in non-aqueous medium

    Energy Technology Data Exchange (ETDEWEB)

    Siddiqui, Mohammed Rafiq Hussain; Al-Wassil, Abdulaziz Ibrahim; Mahfouz, Refaat Mohamad [King Saud University, Riyadh (Saudi Arabia). Department of Chemistry, College of Science; Al-Otaibi, Abdullah Mohmmed [King Abdulaziz City for Science and Technology (Saudi Arabia). The NationalProgram for Advanced Materials and Building Systems

    2012-11-15

    Pure zirconium oxide (ZrO{sub 2}) nanoparticles with diameters 10-25 nm were synthesized from ZrOCl{sub 2}.8H{sub 2}O and Zr(SO{sub 4})2.H{sub 2}O with benzyl alcohol as non-aqueous solvent medium using sol-gel method. Sodium lauryl sulfate was added as surfactants to control the particle size. The synthesized ZrO{sub 2} nanoparticles have a mixture of tetragonal and monoclinic structure. The XRD showed the purity of obtained ZrO{sub 2} nanoparticles with tetragonal and monoclinic phase and the crystallite size for ZrOCl{sub 2}.8H{sub 2}O precursor was estimated to be 18.1 nm and that from Zr(SO{sub 4})2.H{sub 2}O was 9.7 nm. The transmission electron microscopy and scanning electron microscopic studies also shows different sizes of nanoparticles and different morphology depending on the precursor used for the synthesis of ZrO{sub 2} nanoparticles. (author)

  4. Effects of precursor on the morphology and size of ZrO2 nanoparticles, synthesized by sol-gel method in non-aqueous medium

    Directory of Open Access Journals (Sweden)

    Mohammed Rafiq Hussain Siddiqui

    2012-12-01

    Full Text Available Pure zirconium oxide (ZrO2 nanoparticles with diameters 10-25 nm were synthesized from ZrOCl2.8H2O and Zr(SO42.H2O with benzyl alcohol as non-aqueous solvent medium using sol-gel method. Sodium lauryl sulfate was added as surfactants to control the particle size. The synthesized ZrO2 nanoparticles have a mixture of tetragonal and monoclinic structure. The XRD showed the purity of obtained ZrO2 nanoparticles with tetragonal and monoclinic phase and the crystallite size for ZrOCl2.8H2O precursor was estimated to be 18.1 nm and that from Zr(SO42.H2O was 9.7 nm. The transmission electron microscopy and scanning electron microscopic studies also shows different sizes of nanoparticles and different morphology depending on the precursor used for the synthesis of ZrO2 nanoparticles

  5. Synthesis, structural, morphological, optical and magnetic characterization of iron oxide (α-Fe2O3) nanoparticles by precipitation method: Effect of varying the nature of precursor

    Science.gov (United States)

    Lassoued, Abdelmajid; Lassoued, Mohamed Saber; Dkhil, Brahim; Ammar, Salah; Gadri, Abdellatif

    2018-03-01

    α-Fe2O3 nanoparticles were prepared via a precipitation method using each of three different precursors ((FeCl3, 6H2O), (Fe (C5H7O2)3) and (Fe (NO3)3, 9H2O)). The impact of varying the nature of the precursor on crystalline phase, size and magnetic parameters of α-Fe2O3 was examined. Powder X-ray diffraction pattern disclosed rhombohedral structure. The TEM and SEM results showed that the size of α-Fe2O3 nanocrystals was between 21 and 38 nm. FT-IR confirms the phase purity of prepared compounds. Raman studies showed the phonon modes. The TGA showed three mass losses, whereas DTA resulted in three endothermic peaks. The optical investigation exhibited that samples have an optical gap of 2.1 eV. The products exhibited the attractive magnetic properties with high saturation magnetization, which were examined by a vibrating sample magnetometer (VSM).

  6. 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

  7. 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...

  8. 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

  9. Synthesis and characterization of Al{sub 2}O{sub 3} obtained from the polymeric precursor method using glycerin as a poly alcohol; Sintese e caracterizacao de Al{sub 2}O{sub 3} obtida por meio do metodo dos precursores polimericos utilizando glicerina como polialcool

    Energy Technology Data Exchange (ETDEWEB)

    Elicker, C.; Gaier, M.; Almeida, S.R.; Vieiraaa, B.M.; Ratmann, C.W.R.; Pereira, C.M.P. de; Cava, S.S. [Universidade Federal de Pelotas (UFPel), Pelotas, RS (Brazil); Egea, J.J. [Consejo Superior de Investigaciones Cientificas, Madrid (Spain)

    2014-07-01

    In this study, calcium aluminate was synthesized using glycerin to replace ethylene glycol in the polymeric precursor method. The resulting resin was pre-calcined in a muffle at 300 °C for 2 h and the resulting material was calcined at 900 °C for 2 h. The powders were analyzed by XRD, SEM and EDX, TEM, Micro-Raman and IR. The results demonstrated the possibility of using glycerin as an alternative to ethylene glycol in the polymeric precursor method. (author)

  10. The structural studies of aluminosilicate gels and thin films synthesized by the sol-gel method using different Al2O3 and SiO2 precursors

    Directory of Open Access Journals (Sweden)

    Adamczyk Anna

    2015-12-01

    Full Text Available Aluminosilicate materials were obtained by sol-gel method, using different Al2O3 and SiO2 precursors in order to prepare sols based on water and organic solvents. As SiO2 precursors, Aerosil 200TM and tetraethoxysilane TEOS: Si(OC2H54 were applied, while DisperalTM and aluminium secondary butoxide ATSB: Al(OC4H93 were used for Al2O3 ones. Bulk samples were obtained by heating gels at 500 °C, 850 °C and at 1150 °C in air, while thin films were synthesized on carbon, steel and alundum (representing porous ceramics substrates by the dip coating method. Thin films were annealed in air (steel and alundum and in argon (carbon at different temperatures, depending on the substrate type. The samples were synthesized as gels and coatings of the composition corresponding the that of 3Al2O3·2SiO2 mullite because of the specific valuable properties of this material. The structure of the annealed bulk samples and coatings was studied by FT-IR spectroscopy and XRD method (in standard and GID configurations. Additionally, the electron microscopy (SEM together with EDS microanalysis were applied to describe the morphology and the chemical composition of thin films. The analysis of FT-IR spectra and X-ray diffraction patterns of bulk samples revealed the presence of γ-Al2O3 and δ-Al2O3 phases, together with the small amount of SiO2 in the particulate samples. This observation was confirmed by the bands due to vibrations of Al–O bonds occurring in γ-Al2O3 and δ-Al2O3 structures, in the range of 400 to 900 cm−1. The same phases (γ-Al2O3 and δ-Al2O were observed in the deposited coatings, but the presence of particulate ones strongly depended on the type of Al2O3 and SiO2 precursor and on the heat treatment temperature. All thin films contained considerable amounts of amorphous phase.

  11. 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.

  12. The role of tannic acid and sodium citrate in the synthesis of silver nanoparticles

    Science.gov (United States)

    Ranoszek-Soliwoda, Katarzyna; Tomaszewska, Emilia; Socha, Ewelina; Krzyczmonik, Pawel; Ignaczak, Anna; Orlowski, Piotr; Krzyzowska, Małgorzata; Celichowski, Grzegorz; Grobelny, Jaroslaw

    2017-08-01

    We describe herein the significance of a sodium citrate and tannic acid mixture in the synthesis of spherical silver nanoparticles (AgNPs). Monodisperse AgNPs were synthesized via reduction of silver nitrate using a mixture of two chemical agents: sodium citrate and tannic acid. The shape, size and size distribution of silver particles were determined by UV-Vis spectroscopy, dynamic light scattering (DLS) and scanning transmission electron microscopy (STEM). Special attention is given to understanding and experimentally confirming the exact role of the reagents (sodium citrate and tannic acid present in the reaction mixture) in AgNP synthesis. The oxidation and reduction potentials of silver, tannic acid and sodium citrate in their mixtures were determined using cyclic voltammetry. Possible structures of tannic acid and its adducts with citric acid were investigated in aqueous solution by performing computer simulations in conjunction with the semi-empirical PM7 method. The lowest energy structures found from the preliminary conformational search are shown, and the strength of the interaction between the two molecules was calculated. The compounds present on the surface of the AgNPs were identified using FT-IR spectroscopy, and the results are compared with the IR spectrum of tannic acid theoretically calculated using PM6 and PM7 methods. The obtained results clearly indicate that the combined use of sodium citrate and tannic acid produces monodisperse spherical AgNPs, as it allows control of the nucleation, growth and stabilization of the synthesis process. [Figure not available: see fulltext.

  13. 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.)

  14. 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.

  15. Ionospheric earthquake precursors

    International Nuclear Information System (INIS)

    Bulachenko, A.L.; Oraevskij, V.N.; Pokhotelov, O.A.; Sorokin, V.N.; Strakhov, V.N.; Chmyrev, V.M.

    1996-01-01

    Results of experimental study on ionospheric earthquake precursors, program development on processes in the earthquake focus and physical mechanisms of formation of various type precursors are considered. Composition of experimental cosmic system for earthquake precursors monitoring is determined. 36 refs., 5 figs

  16. Preparation of Cu{sub 2}ZnSnS{sub 4} thin films by sulfurizing stacked precursor thin films via successive ionic layer adsorption and reaction method

    Energy Technology Data Exchange (ETDEWEB)

    Su Zhenghua; Yan Chang; Sun Kaiwen; Han Zili [School of Metallurgical Science and Engineering, Central South University, Changsha 410083 (China); Liu Fangyang, E-mail: liufangyang@csu.edu.cn [School of Metallurgical Science and Engineering, Central South University, Changsha 410083 (China); Liu Jin [School of Metallurgical Science and Engineering, Central South University, Changsha 410083 (China); Lai Yanqing, E-mail: laiyanqingcsu@163.com [School of Metallurgical Science and Engineering, Central South University, Changsha 410083 (China); Li Jie; Liu Yexiang [School of Metallurgical Science and Engineering, Central South University, Changsha 410083 (China)

    2012-07-15

    Earth-abundant Cu{sub 2}ZnSnS{sub 4} is a promising alternative photovoltaic material which has been examined as absorber layer of thin film solar cells. In this study, Cu{sub 2}ZnSnS{sub 4} (CZTS) thin films have been successfully fabricated by sulfurizing stacked precursor thin films via successive ionic layer adsorption and reaction (SILAR) method. The prepared CZTS thin films have been characterized by X-ray diffraction, energy dispersive spectrometer, Raman spectroscopy, UV-vis spectroscopy, Hall effect measurements and photoelectrochemical tests. Results reveal that the thin films have kesterite structured Cu{sub 2}ZnSnS{sub 4} and the p-type conductivity with a carrier concentration in the order of 10{sup 18} cm{sup -3} and an optical band gap of 1.5 eV, which are suitable for applications in thin film solar cells.

  17. Structural and optical characterization of Eu3+ doped beta-Ga2O3 nanoparticles using a liquid-phase precursor method.

    Science.gov (United States)

    Kim, Moung-O; Kang, Bongkyun; Yoon, Daeho

    2013-08-01

    Eu3+ doped beta-Ga2O3 and non-doped beta-Ga2O3 nanoparticles were synthesized at 800 degrees C using a liquid-phase precursor (LPP) method, with different annealing times and Eu3+ ion concentrations. Eu3+ doped beta-Ga2O3 nanoparticles showed broad XRD peaks, revealing a second phase compared with the non-doped beta-Ga2O3 nanoparticles. The cathode luminescence (CL) spectra of beta-Ga2O3 and Eu3+ doped beta-Ga2O3 nanoparticles showed a broad band emission (300-500 nm) of imperfection and two component emissions. The luminescence quenching properties of Eu3+ dopant ion concentration appeared gradually beyond 5 mol% in our investigation.

  18. 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

  19. Catalytic oxidation of n-hexane promoted by Ce1−xCuxO2 catalysts prepared by one-step polymeric precursor method

    International Nuclear Information System (INIS)

    Araújo, Vinícius D.; Lima, Maurício M. de; Cantarero, Andrés; Bernardi, Maria I.B.; Bellido, Jorge D.A.; Assaf, Elisabete M.; Balzer, Rosana; Probst, Luiz F.D.; Fajardo, Humberto V.

    2013-01-01

    Ceria-supported copper catalysts (Ce 1−x Cu x O 2 , with x (mol) = 0, 0.01, 0.03, 0.05 and 0.10) were prepared in one step through the polymeric precursor method. The textural properties of the catalysts were investigated by X-ray diffraction (XRD), Rietveld refinement, N 2 -physisorption (BET surface area), electron paramagnetic resonance (EPR), UV–visible diffuse reflectance and photoluminescence spectroscopies and temperature-programmed reduction (TPR). In a previous study ceria-supported copper catalysts were found to be efficient in the preferential oxidation of CO. In this study, we extended the catalytic application of Ce 1−x Cu x O 2 systems to n-hexane oxidation and it was verified that the catalysts were highly efficient in the proposed reaction. The best performance (up to 95% conversion) was observed for the catalysts with low copper loads (Ce 0.97 Cu 0.03 O 2 and Ce 0.99 Cu 0.01 O 2 , respectively). The physicochemical characterizations revealed that these behaviors could be attributed to the copper species present in the catalysts and the interaction between CuO and CeO 2 , which vary according to the copper content. - Highlights: • Synthesis of CuO/CeO2 catalysts by the one-step polymeric precursor method. • 95% n-hexane conversion on Ce0.97Cu0.03O2 catalyst. • Redox properties play a key role in the catalytic performance

  20. Synthesis of flower-like LiMnPO4/C with precipitated NH4MnPO4·H2O as precursor

    International Nuclear Information System (INIS)

    Liu Jiali; Hu Dongge; Huang Tao; Yu Aishui

    2012-01-01

    Highlights: ► Flower-like NH 4 MnPO 4 ·H 2 O is obtained by novel precipitating method. ► It is used as the precursor to synthesize LiMnPO 4 /C. ► Subsequent heat treatment would not destroy the precursor morphology. ► As-prepared LiMnPO 4 /C showed discharge capacity of 85 mAh/g at 0.05 C. - Abstract: Ammonium magnesium phosphate monohydrate (NH 4 MnPO 4 ·H 2 O) precursor was prepared by a novel precipitating process with manganese citrate complexes as intermediate. The morphology of the precursor observed by Scanning Electron Microscope (SEM) was flower-like which was self-assembled by plate-like particles. Further analysis by X-ray diffraction (XRD) revealed that the lattice of the plate crystal was orientated along (0 1 0) plane. By solid-state reaction of the precursor, with lithium acetate and glucose as carbon source, pure olivine structured LiMnPO 4 /C composite was obtained and meanwhile, the original flower-like morphology could be retained.

  1. Electroluminescence of zinc oxide thin-films prepared via polymeric precursor and via sol-gel methods

    International Nuclear Information System (INIS)

    Lima, S.A.M.; Cremona, M.; Davolos, M.R.; Legnani, C.; Quirino, W.G.

    2007-01-01

    Zinc oxide (ZnO) is an electroluminescent (EL) material that can emit light in different regions of electromagnetic spectrum when electrically excited. Since ZnO is chemically stable, inexpensive and environmentally friendly material, its EL property can be useful to construct solid-state lamps for illumination or as UV emitter. We present here two wet chemical methods to prepare ZnO thin-films: the Pechini method and the sol-gel method, with both methods resulting in crystalline and transparent films with transmittance >85% at 550 nm. These films were used to make thin-film electroluminescent devices (TFELD) using two different insulator layers: lithium fluoride (LiF) or silica (SiO 2 ). All the devices exhibit at least two wide emission bands in the visible range centered at 420 nm and at 380 nm attributed to the electronic defects in the ZnO optical band gap. Besides these two bands, the device using SiO 2 and ZnO film obtained via sol-gel exhibits an additional band in the UV range centered at 350 nm which can be attributed to excitonic emission. These emission bands of ZnO can transfer their energy when a proper dopant is present. For the devices produced the voltage-current characteristics were measured in a specific range of applied voltage

  2. Effect of precursor and preparation method on manganese based activated carbon sorbents for removing H2S from hot coal gas.

    Science.gov (United States)

    Wang, Jiancheng; Qiu, Biao; Han, Lina; Feng, Gang; Hu, Yongfeng; Chang, Liping; Bao, Weiren

    2012-04-30

    Activated carbon (AC) supported manganese oxide sorbents were prepared by the supercritical water impregnation (SCWI) using two different precursor of Mn(NO(3))(2) (SCW(N)) and Mn(Ac)(2)·4H(2)O (SCW(A)). Their capacities of removing H(2)S from coal gas were evaluated and compared to the sorbents prepared by the pore volume impregnation (PVI) method. The structure and composition of different sorbents were characterized by XRD, SEM, TEM, XPS and XANES techniques. It is found that the precursor of active component plays the crucial role and SCW(N) sorbents show much better sulfidation performance than the SCW(A) sorbents. This is because the Mn(3)O(4) active phase of the SCW(N) sorbents are well dispersed on the AC support, while the Mn(2)SiO(4)-like species in the SCW(A) sorbent can be formed and seriously aggregated. The SCW(N) sorbents with 2.80% and 5.60% manganese are favorable for the sulfidation reaction, since the Mn species are better dispersed on the SCW(N) sorbents than those on the PV(N) sorbents and results in the better sulfidation performance of the SCW(N) sorbents. As the Mn content increases to 11.20%, the metal oxide particles on AC supports aggregate seriously, which leads to poorer sulfidation performance of the SCW(N)11.20% sorbents than that of the PV(N)11.20% sorbents. Copyright © 2012 Elsevier B.V. All rights reserved.

  3. Use of 67Ga citrate in the diagnosis of lung cancer

    International Nuclear Information System (INIS)

    Bogdasarov, Yu.B.; Zajtseva, T.I.; Gabuniya, R.I.; Abramov, V.F.

    1981-01-01

    A study was of the potentialities of 67 Ga citrate in the diagnosis of lung cancer, in differentiation from benign tumors and chronic inflammatory processes of the lungs. A total of 101 lung cancer patients were examined, of them 64 with central, and 37 with peripheral cancer. The results of radionuclide studies were correlated with those of surgery and with morphological findings. It has been established that in central cancer scintigraphy with 67 Ga citrate gives positive results in 87% of cases, and in peripheral cancer in 89%. This method is of great value for the diagnosis of cancer metastases to the mediastinal lymph nodes. No correlation between the intensity of 67 Ga citrate accumulation in lung tumors and their histological structure has been revealed [ru

  4. 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.

  5. 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

  6. 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.

  7. Methods to uncover an antibody epitope in the KPI domain of Alzheimer's amyloid precursor protein for immunohistochemistry in human brain.

    Science.gov (United States)

    Campbell, E; Pearson, R C; Parkinson, D

    1999-11-15

    A novel polyclonal antibody (Ab993), specific for a KPI domain epitope of APP, was characterised for use in immunoprecipitation, Western blotting and immunohistochemistry. Conditioned medium from NTera2/D1 cells was used for immunoprecipitation and Western blots. Paraffin-embedded human brain sections were used for immunohistochemistry. The antibody recognised KPI-containing APP on Western blots after standard solubilisation but immunoprecipitation of soluble APP required reduction with 2-mercaptoethanol followed by alkylation of reduced sulphydryl bonds with sodium iodoacetate. Immunohistochemical staining of human brain sections was significantly enhanced by this pre-treatment. Microwaving of sections also increased immunolabelling, by a mechanism that was additive to reduction and alkylation. Incubation in 80% formic acid did not confer any enhancement of immunoreactivity. Ab993, applied with the methods reported here, is expected to be valuable in investigations of the pathogenesis of Alzheimer's disease to determine the source of the beta-amyloid peptide.

  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. Differentiation of malignant and degenerative benign bone disease using 99mTc-citrate scintigraphy

    International Nuclear Information System (INIS)

    Guo Rui; Jin Jianhua; Li Sijin; Li Xianfeng; Zhang Xiaojuan; Ren Yuan

    2008-01-01

    Objective: To differentiate malignant and degenerative benign bone disease using 99m Tc- citrate scintigraphy. Methods: Thirty-nine patients (92 lesions) with confirmed malignant bone disease or degenerative benign bone disease were studied, for which the results of 99m Te-methylene diphosphonate( 99m Tc- MDP) scintigraphy were positive. 99m Tc-citrate scintigraphy was performed within a time interval of 2-7 days after 99m Tc-MDP scintigraphy. Visual analysis and semiquantitative analysis were applied. Each lesion was scored as malignant or benign, which was independently verified, using conventional techniques (histopathology, X-ray, CT, MRI and clinical follow up). Results: In visual analysis of 99m Tc-citrate imaging, most malignant lesions (35/48, 72.92%) clearly showed high radioactivity accumulation, while most benign lesions (39/44, 88.64%) had not obviously visible uptake of 99m Tc-citrate. In semiquantitative analysis of 99m Tc- citrate image, malignant lesions demonstrated a higher lesion-to-background radioisotope uptake ratio (RUR) than that of benign degenerative lesions (1.47 ± 0.42 vs. 1.09 ± 0.38, t=2.887, P 99m Tc-MDP in the two groups is of the same (1.96 ± 0.25 vs. 1.87 ± 0.21, t=1.178, P>0.20). Conclusion: 99m Tc- citrate scintigraphy is a promising method to differentiate malignant from benign degenerative lesions seen as areas of increased activity on 99m Tc-MDP bone scintigraphy. (authors)

  10. Capillary electrophoresis with indirect UV detection for the determination of stabilizers and citrates present in human albumin solutions.

    Science.gov (United States)

    Jaworska, Małgorzata; Cygan, Paulina; Wilk, Małgorzata; Anuszewska, Elzbieta

    2009-08-15

    Sodium caprylate and N-acetyltryptophan are the most frequently used stabilizers that protect the albumin from aggregation or heat induced denaturation. In turn citrates - excipients remaining after fractionation process - can be treated as by-product favoring leaching aluminum out of glass containers whilst albumin solution is stored. With ionic nature these substances have all the markings of a subject for capillary electrophoresis analysis. Thus CE methods were proposed as new approach for quality control of human albumin solution in terms of determination of stabilizers and citrates residue. Human albumin solutions both 5% and 20% from various manufacturers were tested. Indirect detection mode was set to provide sufficient detectability of analytes lacking of chromophores. As being anions analytes were separated with reversed electroosmotic flow. As a result of method optimization two background electrolytes based on p-hydroxybenzoic acid and 2,6-pyridinedicarboxylic acid were selected for stabilizers and citrates separation, respectively. The optimized methods were successfully validated. For citrates that require quantification below 100microM the method demonstrated the precision less than 4% and the limit of detection at 4microM. In order to check the new methods accuracy and applicability the samples were additionally tested with selected reference methods. The proposed methods allow reliable quantification of stabilizers and citrates in human albumin solution that was confirmed by method validation as well as result comparison with reference methods. The CE methods are considered to be suitable for quality control yet simplifying and reducing cost of analysis.

  11. Structural, morphological and thermal properties of La1-xSrxMnO3 (x = 0.15 and 0.22) prepared by the polymeric precursor method

    International Nuclear Information System (INIS)

    Macedo, D.A; Cela, B.; Carvalho, W.M.; Martinelli, A.E.; Nascimento, R.M.; Paskocimas, C.A.

    2009-01-01

    Strontium-doped lanthanum manganite (La1 -x Sr x MnO 3 or LSM) is traditionally the most used material for cathodes in high temperature solid oxide fuel cell (800 deg C). This material shows excellent electrocatalytic activity for oxygen reduction and is chemical and thermal stable with the yttria-stabilized zirconia electrolyte (YSZ). In this work La 0.85 Sr 0.15 MnO 3 (LSM 15) and La 0.78 Sr 0.22 MnO 3 (LSM 22) were prepared by the polymeric precursor method, calcinated at 700 deg C for 2 h and characterized by X-ray diffraction, particle size analysis, scanning electronic microscopy and compacts' dilatometry. The synthesis method used provided the attainment of nanopowders with perovskite structure and particles sizes below 100 nm. The thermal expansion coefficients of LSM 15 and LSM 22 were found to be 12.2 x 10 -6 deg C -1 and 11.7 x 10 -6 deg C -1 respectively, which are very close to that of the YSZ. (author)

  12. Synthesis and characterization of scandia ceria stabilized zirconia powders prepared by polymeric precursor method for integration into anode-supported solid oxide fuel cells

    Science.gov (United States)

    Tu, Hengyong; Liu, Xin; Yu, Qingchun

    2011-03-01

    Scandia ceria stabilized zirconia (10Sc1CeSZ) powders are synthesized by polymeric precursor method for use as the electrolyte of anode-supported solid oxide fuel cell (SOFC). The synthesized powders are characterized in terms of crystalline structure, particle shape and size distribution by X-ray diffraction (XRD), transmission electron microscopy (TEM) and photon correlation spectroscopy (PCS). 10Sc1CeSZ electrolyte films are deposited on green anode substrate by screen-printing method. Effects of 10Sc1CeSZ powder characteristics on sintered films are investigated regarding the integration process for application as the electrolytes in anode-supported SOFCs. It is found that the 10Sc1CeSZ films made from nano-sized powders with average size of 655 nm are very porous with many open pores. In comparison, the 10Sc1CeSZ films made from micron-sized powders with average size of 2.5 μm, which are obtained by calcination of nano-sized powders at higher temperatures, are much denser with a few closed pinholes. The cell performances are 911 mW cm-2 at the current density of 1.25 A cm-2 and 800 °C by application of Ce0.8Gd0.2O2 (CGO) barrier layer and La0.6Sr0.4CoO3 (LSC) cathode.

  13. Synthesis and characterization of a layered double hydroxide containing an intercalated nickel(II) citrate complex

    International Nuclear Information System (INIS)

    Wang Lianying; Wu Guoqing; Evans, David G.

    2007-01-01

    The nickel(II) citrate complex anion ([Ni(C 6 H 4 O 7 )] 2- ) may be intercalated into the interlayer galleries of a layered double hydroxide (LDH) host by a process involving ion-exchange with an Mg 2 Al-NO 3 LDH precursor. The powder X-ray diffraction (XRD) pattern confirms that the layered structure is maintained. The thermal decomposition process of the complex anion-intercalated material has been characterized by in situ high temperature powder XRD, thermogravimetry-differential thermal analysis (TG-DTA) and coupled with mass spectrometry (MS). The thermal stability of the nickel(II) citrate complex anion intercalated in LDHs in air is lower than that in the sodium salt. Calcination generates a high degree of nickel(II) oxide dispersion in a matrix of magnesium and aluminium oxide phases which should be an advantage if the materials are used as catalyst precursors. Based on the observed data, a structural model for the [Ni(C 6 H 4 O 7 )] 2- anion intercalated in the galleries of the LDH is proposed

  14. 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...

  15. Rapid synthesis of macrocycles from diol precursors

    DEFF Research Database (Denmark)

    Wingstrand, Magnus; Madsen, Charlotte Marie; Clausen, Mads Hartvig

    2009-01-01

    A method for the formation of synthetic macrocycles with different ring sizes from diols is presented. Reacting a simple diol precursor with electrophilic reagents leads to a cyclic carbonate, sulfite or phosphate in a single step in 25-60% yield. Converting the cyclization precursor to a bis-ele...

  16. Identified EM Earthquake Precursors

    Science.gov (United States)

    Jones, Kenneth, II; Saxton, Patrick

    2014-05-01

    Many attempts have been made to determine a sound forecasting method regarding earthquakes and warn the public in turn. Presently, the animal kingdom leads the precursor list alluding to a transmission related source. By applying the animal-based model to an electromagnetic (EM) wave model, various hypotheses were formed, but the most interesting one required the use of a magnetometer with a differing design and geometry. To date, numerous, high-end magnetometers have been in use in close proximity to fault zones for potential earthquake forecasting; however, something is still amiss. The problem still resides with what exactly is forecastable and the investigating direction of EM. After a number of custom rock experiments, two hypotheses were formed which could answer the EM wave model. The first hypothesis concerned a sufficient and continuous electron movement either by surface or penetrative flow, and the second regarded a novel approach to radio transmission. Electron flow along fracture surfaces was determined to be inadequate in creating strong EM fields, because rock has a very high electrical resistance making it a high quality insulator. Penetrative flow could not be corroborated as well, because it was discovered that rock was absorbing and confining electrons to a very thin skin depth. Radio wave transmission and detection worked with every single test administered. This hypothesis was reviewed for propagating, long-wave generation with sufficient amplitude, and the capability of penetrating solid rock. Additionally, fracture spaces, either air or ion-filled, can facilitate this concept from great depths and allow for surficial detection. A few propagating precursor signals have been detected in the field occurring with associated phases using custom-built loop antennae. Field testing was conducted in Southern California from 2006-2011, and outside the NE Texas town of Timpson in February, 2013. The antennae have mobility and observations were noted for

  17. 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

  18. 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)

  19. Sodium citrate assisted facile synthesis of AuPd alloy networks for ethanol electrooxidation with high activity and durability

    Science.gov (United States)

    Zhai, Yanling; Zhu, Zhijun; Lu, Xiaolin; Zhou, H. Susan

    2016-10-01

    The direct ethanol fuel cell is an emerging energy conversion device for which palladium is considered as the one of the most effective components for anode catalyst, however, its widespread application has been still limited by the activity and durability of the anode catalyst. In this work, AuPd alloy networks (NWs) are synthesized using H2PdCl4 and HAuCl4 as precursors reduced by NaBH4 in the presence of sodium citrate (SC). The results reveal that SC plays significant role in network structure, resulting in the enhanced electrocatalytic activity of the catalyst. This self-supported AuPd NWs catalyst exhibits much higher electrochemical catalytic activity than commercial Pd/C catalyst toward ethanol electrooxidation in alkaline solution. Significantly, AuPd NWs catalyst shows extremely high durability at the beginning of the chronoamperometry test, and as high as 49% of the mass current density (1.41 A/mgPd) remains after 4000 s current-time test at -0.3 V (vs. Ag/AgCl) in N2-saturated KOH-ethanol solution. This strategy provides a facile method for the preparation of alloy networks with high electrochemical activity, and can be potentially expanded to a variety of electrochemical applications.

  20. Mechanical performance and thermal stability of glass fiber reinforced silica aerogel composites based on co-precursor method by freeze drying

    Science.gov (United States)

    Zhou, Ting; Cheng, Xudong; Pan, Yuelei; Li, Congcong; Gong, Lunlun; Zhang, Heping

    2018-04-01

    In order to maintain the integrity, glass fiber (GF) reinforced silica aerogel composites were synthesized using methltrimethoxysilane (MTMS) and water glass co-precursor by freeze drying method. The composites were characterized by scanning electron microscopy, Brunauer-Emmett-Teller analysis, uniaxial compressive test, three-point bending test, thermal conductivity analysis, contact angle test, TG-DSC analysis. It was found that the molar ratio of MTMS/water glass could significantly affect the properties of composites. The bulk density and thermal conductivity first decreased and then increased with the increasing molar ratio. The composites showed remarkable mechanical strength and flexibility compared with pure silica aerogel. Moreover, when the molar ratio is 1.8, the composites showed high specific surface area (870.9 m2/g), high contact angle (150°), great thermal stability (560 °C) and low thermal conductivity (0.0248 W/m·K). These outstanding properties indicate that GF/aerogels have broad prospects in the field of thermal insulation.

  1. Bismuth-doped Cu(In,Ga)Se{sub 2} absorber prepared by multi-layer precursor method and its solar cell

    Energy Technology Data Exchange (ETDEWEB)

    Chantana, Jakapan; Hironiwa, Daisuke; Minemoto, Takashi [Department of Electrical and Electronic Engineering, Ritsumeikan University, 1-1-1 Nojihigashi, Kusatsu, Shiga 525-8577 (Japan); Watanabe, Taichi; Teraji, Seiki; Kawamura, Kazunori [Environment and Energy Research Center, Nitto Denko Corporation, 2-8 Yamadaoka, Suita, Osaka 565-0871 (Japan)

    2015-06-15

    Bismuth (Bi)-doped Cu(In,Ga)Se{sub 2} (CIGS) films were prepared by the so-called ''multi-layer precursor method'', obtained by depositing them onto Bi layers with various thicknesses on Mo-coated soda-lime glass (SLG) substrates. Material composition (Cu, In, Ga, and Se) profiles of the CIGS films are almost identical, whereas sodium (Na) is reduced, when Bi thickness is increased. Moreover, the incorporation of Bi into the CIGS film is enhanced with thicker Bi layer. With Bi thickness from 0 to 70 nm, the 2.4-μm-thick CIGS absorbers demonstrate the increase in CIGS grain size, carrier lifetime, and carrier concentration, thus improving their cell performances, especially open-circuit voltage (V{sub OC}). With further increase in Bi thickness of above 70 nm, the CIGS films show the deterioration of CIGS film quality owing to the formation of Bi compounds such as Bi, BiSe, and Bi{sub 4}Se{sub 3}. Consequently, Bi-doped CIGS absorber with thickness of 2.4 μm, prepared with the 70-nm-thick Bi layer on Mo-coated SLG substrate, gives rise to the improvement of photovoltaic performances, especially V{sub OC}. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  2. The usability of ark clam shell (Anadara granosa) as calcium precursor to produce hydroxyapatite nanoparticle via wet chemical precipitate method in various sintering temperature.

    Science.gov (United States)

    Khiri, Mohammad Zulhasif Ahmad; Matori, Khamirul Amin; Zainuddin, Norhazlin; Abdullah, Che Azurahanim Che; Alassan, Zarifah Nadakkavil; Baharuddin, Nur Fadilah; Zaid, Mohd Hafiz Mohd

    2016-01-01

    This paper reported the uses of ark clam shell calcium precursor in order to form hydroxyapatite (HA) via the wet chemical precipitation method. The main objective of this research is to acquire better understanding regarding the effect of sintering temperature in the fabrication of HA. Throughout experiment, the ratio of Ca:P were constantly controlled, between 1.67 and 2.00. The formation of HA at these ratio was confirmed by means of energy-dispersive X-ray spectroscopy analysis. In addition, the effect of sintering temperature on the formation of HA was observed using X-ray diffraction analysis, while the structural and morphology was determined by means of field emission scanning electron microscopy. The formation of HA nanoparticle was recorded (~35-69 nm) in the form of as-synthesize HA powder. The bonding compound appeared in the formation of HA was carried out using Fourier transform infrared spectroscopy such as biomaterials that are expected to find potential applications in orthopedic and biomedical industries .

  3. Bismuth-doped Cu(In,Ga)Se2 absorber prepared by multi-layer precursor method and its solar cell

    International Nuclear Information System (INIS)

    Chantana, Jakapan; Hironiwa, Daisuke; Minemoto, Takashi; Watanabe, Taichi; Teraji, Seiki; Kawamura, Kazunori

    2015-01-01

    Bismuth (Bi)-doped Cu(In,Ga)Se 2 (CIGS) films were prepared by the so-called ''multi-layer precursor method'', obtained by depositing them onto Bi layers with various thicknesses on Mo-coated soda-lime glass (SLG) substrates. Material composition (Cu, In, Ga, and Se) profiles of the CIGS films are almost identical, whereas sodium (Na) is reduced, when Bi thickness is increased. Moreover, the incorporation of Bi into the CIGS film is enhanced with thicker Bi layer. With Bi thickness from 0 to 70 nm, the 2.4-μm-thick CIGS absorbers demonstrate the increase in CIGS grain size, carrier lifetime, and carrier concentration, thus improving their cell performances, especially open-circuit voltage (V OC ). With further increase in Bi thickness of above 70 nm, the CIGS films show the deterioration of CIGS film quality owing to the formation of Bi compounds such as Bi, BiSe, and Bi 4 Se 3 . Consequently, Bi-doped CIGS absorber with thickness of 2.4 μm, prepared with the 70-nm-thick Bi layer on Mo-coated SLG substrate, gives rise to the improvement of photovoltaic performances, especially V OC . (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  4. Precursor incident program at EDF

    International Nuclear Information System (INIS)

    Fourest, B.; Maliverney, B.; Rozenholc, M.; Piovesan, C.

    1998-01-01

    The precursor program was started by EDF in 1994, after an investigation of the US NRC's Accident Sequence Precursor Program. Since then, reported operational events identified as Safety Outstanding Events have been analyzed whenever possible using probabilistic methods based on PSAs. Analysis provides an estimate of the remaining protection against core damage at the time the incident occurred. Measuring the incidents' severity enables to detect incidents important regarding safety. Moreover, the most efficient feedback actions can be derived from the main accident sequences identified through the analysis. Therefore, incident probabilistic analysis provides a way to assess priorities in terms of treatment and resource allocation, and so, to implement countermeasures preventing further occurrence and development of the most significant incidents. As some incidents cannot be analyzed using this method, probabilistic analysis can only be one among the methods used to assess the nuclear power plants' safety level. Nevertheless, it provides an interesting complement to classical methods of deterministic studies. (author)

  5. 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

  6. 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.

  7. Thermal-annealing effects on the structural and magnetic properties of 10% Fe-doped SnO{sub 2} nanoparticles synthetized by a polymer precursor method

    Energy Technology Data Exchange (ETDEWEB)

    Aragón, F.H., E-mail: fermin964@hotmail.com [Núcleo de Física Aplicada, Instituto de Física, Universidade de Brasília, Brasília DF 70910-900 (Brazil); Instituto de Ciências Biológicas, Pós-graduação em Nanociência e Nanobiotecnologia, Universidade de Brasília, Brasilia DF 70919-970 (Brazil); Coaquira, J.A.H. [Núcleo de Física Aplicada, Instituto de Física, Universidade de Brasília, Brasília DF 70910-900 (Brazil); Nagamine, L.C.C.M.; Cohen, R. [Instituto de Física, Universidade de São Paulo, São Paulo SP 05508-090 (Brazil); Silva, S.W. da [Núcleo de Física Aplicada, Instituto de Física, Universidade de Brasília, Brasília DF 70910-900 (Brazil); Instituto de Ciências Biológicas, Pós-graduação em Nanociência e Nanobiotecnologia, Universidade de Brasília, Brasilia DF 70919-970 (Brazil); and others

    2015-02-01

    In this work, we present the experimental results of Sn{sub 0.9}Fe{sub 0.1}O{sub 2} nanoparticles synthesized by a polymer precursor method. Studies were performed in the as-prepared (AP) and thermally-annealed (TA) samples. The X-ray diffraction (XRD) data analysis carried out using the Rietveld refinement method shows the formation of only the rutile-type structure in the AP sample and this phase remains stable for the TA sample. Additionally, the mean crystallite size shows an increase from ∼4 nm to ∼17 nm after the annealing and a clear reduction of the residual strain has also been determined. Micro-Raman spectroscopy measurements show the formation of an iron oxide phase (likely α-Fe{sub 2}O{sub 3}) after the thermal treatment. Magnetic measurements show a paramagnetic behavior for the AP sample and the coexistence of a weak ferromagnetism and paramagnetism for the TA sample. The magnetically-ordered contribution of the TA sample has been assigned to the formation of the hematite phase. DC and AC magnetic features of the TA sample are consistent with a cluster-glass behavior which seems to be related to the magnetic disorder of spins located at the particle surface. Those spins clusters seem to be formed due to the diffusion of iron ions from the core of the particle to the surface caused by the annealing process. - Highlights: • Thermal annealing effects in the 10% Fe-doped SnO{sub 2} nanoparticles have been studied. • XRD data analysis shows the formation of the rutile-type structure. • Raman measurements show the formation of small amount of α-Fe{sub 2}O{sub 3} after the annealing. • Paramagnetic and magnetically ordered phases were determined after the annealing. • Spin clusters likely at the particle surface have been formed after the annealing.

  8. 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

  9. 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 ...

  10. 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

  11. Layered double hydroxide supported gold nanoclusters by glutathione-capped Au nanoclusters precursor method for highly efficient aerobic oxidation of alcohols

    Science.gov (United States)

    Li, Lun; Dou, Liguang; Zhang, Hui

    2014-03-01

    M3Al-layered double hydroxide (LDH, M = Mg, Ni, Co) supported Au nanoclusters (AuNCs) catalysts have been prepared for the first time by using water-soluble glutathione-capped Au nanoclusters as precursor. Detailed characterizations show that the ultrafine Au nanoclusters (ca. 1.5 +/- 0.6 nm) were well dispersed on the surface of LDH with a loading of Au below ~0.23 wt% upon synergetic interaction between AuNCs and M3Al-LDH. AuNCs/Mg3Al-LDH-0.23 exhibits much higher catalytic performance for the oxidation of 1-phenylethanol in toluene than Au/Mg3Al-LDH(DP) by the conventional deposition precipitation method and can be applied for a wide range of alcohols without basic additives. This catalyst can also be reused without loss of activity or selectivity. The AuNCs/M(= Ni, Co)3Al-LDH catalysts present even higher alcohol oxidation activity than AuNCs/Mg3Al-LDH. Particularly, AuNCs/Ni3Al-LDH-0.22 exhibits the highest activity (46 500 h-1) for the aerobic oxidation of 1-phenylethanol under solvent-free conditions attributed to its strongest Au-support synergy. The excellent activity and stability of AuNCs/M3Al-LDH catalysts render these materials promising candidates for green base-free selective oxidation of alcohols by molecular oxygen.M3Al-layered double hydroxide (LDH, M = Mg, Ni, Co) supported Au nanoclusters (AuNCs) catalysts have been prepared for the first time by using water-soluble glutathione-capped Au nanoclusters as precursor. Detailed characterizations show that the ultrafine Au nanoclusters (ca. 1.5 +/- 0.6 nm) were well dispersed on the surface of LDH with a loading of Au below ~0.23 wt% upon synergetic interaction between AuNCs and M3Al-LDH. AuNCs/Mg3Al-LDH-0.23 exhibits much higher catalytic performance for the oxidation of 1-phenylethanol in toluene than Au/Mg3Al-LDH(DP) by the conventional deposition precipitation method and can be applied for a wide range of alcohols without basic additives. This catalyst can also be reused without loss of activity

  12. Methanol oxidation reaction on Ti/RuO{sub 2(x)}Pt{sub (1-x)} electrodes prepared by the polymeric precursor method

    Energy Technology Data Exchange (ETDEWEB)

    Freitas, R.G.; Marchesi, L.F.; Mattos-Costa, F.I.; Pereira, E.C. [Laboratorio Interdisciplinar de Eletroquimica e Ceramica, Centro Multidisciplinar para o Desenvolvimento de Materiais Ceramicos, Departamento de Quimica, Universidade Federal de Sao Carlos, Caixa Postal 676, 13560-905 Sao Carlos, SP (Brazil); Oliveira, R.T.S. [Laboratorio Interdisciplinar de Eletroquimica e Ceramica, Centro Multidisciplinar para o Desenvolvimento de Materiais Ceramicos, Departamento de Quimica, Universidade Federal de Sao Carlos, Caixa Postal 676, 13560-905 Sao Carlos, SP (Brazil); Grupo de Materiais Eletroquimicos e Metodos Eletroanaliticos, Instituto de Quimica de Sao Carlos, Universidade de Sao Paulo, Caixa Postal 780, 13566-590 Sao Carlos, SP (Brazil); LEMN, Laboratorio de Eletroquimica e Materiais Nanoestruturados, CCNH-Centro de Ciencias Naturais e Humanas, UFABC-Universidade Federal do ABC, CEP 09.210-170, Rua Santa Adelia 166, Bairro Bangu, Santo Andre, SP (Brazil); Bulhoes, L.O.S. [Laboratorio Interdisciplinar de Eletroquimica e Ceramica, Centro Multidisciplinar para o Desenvolvimento de Materiais Ceramicos, Departamento de Quimica, Universidade Federal de Sao Carlos, Caixa Postal 676, 13560-905 Sao Carlos, SP (Brazil); CENIP, Centro Universitario Central Paulista, UNICEP, Rua Miguel Petroni, 5111, CEP 13563-470, Sao Carlos, SP (Brazil); Santos, M.C. [Laboratorio Interdisciplinar de Eletroquimica e Ceramica, Centro Multidisciplinar para o Desenvolvimento de Materiais Ceramicos, Departamento de Quimica, Universidade Federal de Sao Carlos, Caixa Postal 676, 13560-905 Sao Carlos, SP (Brazil); LEMN, Laboratorio de Eletroquimica e Materiais Nanoestruturados, CCNH-Centro de Ciencias Naturais e Humanas, UFABC-Universidade Federal do ABC, CEP 09.210-170, Rua Santa Adelia 166, Bairro Bangu, Santo Andre, SP (Brazil)

    2007-09-27

    In this work, ruthenium oxide films containing platinum nanoparticles were prepared using the polymeric precursor method on Ti substrates with several molar ratios. This paper aims at presenting the characterization of the Pt content effect in the methanol electrochemical oxidation reaction. The films were physically characterized using X-ray diffraction and both Pt and RuO{sub 2} (rutile) phases were observed. The mean crystallite sizes were 6 nm for Pt and 25 nm for RuO{sub 2}. The X-ray photoelectronic results indicated that on the electrodes surfaces, depending on the substrate, there was RuO{sub 2}, Ru metal and Pt metal. Besides, it was not observed the formation of PtRu alloys. The atomic force microscopy images of the films showed highly rough surfaces. A decrease in the roughness mean square values is observed as the Pt content increases. These last results are similar to electroactive surface area values calculated by redox-couple (K{sub 4}FeCN{sub 6}/K{sub 3}FeCN{sub 6}). There was an increase in the globular size observed on the electrode surface and lower particle dispersion as the Pt content is increased from 12.5 to 75 mol%. Regarding the eletrode electrocatalytical behavior for methanol oxidation, it was observed that the onset oxidation overpotential is displaced towards more negative values as Pt content is decreased. Besides, an increase has been shown in the current density for methanol oxidation of 600% using a Ti/RuO{sub 2}-Pt (87.5:12.5) electrode compared to polycrystalline Pt. (author)

  13. Earthquakes: hydrogeochemical precursors

    Science.gov (United States)

    Ingebritsen, Steven E.; Manga, Michael

    2014-01-01

    Earthquake prediction is a long-sought goal. Changes in groundwater chemistry before earthquakes in Iceland highlight a potential hydrogeochemical precursor, but such signals must be evaluated in the context of long-term, multiparametric data sets.

  14. 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

  15. Determining the chemical exchange saturation transfer (CEST) behavior of citrate and spermine under in vivo conditions

    Science.gov (United States)

    Basharat, Meer; deSouza, Nandita M.; Parkes, Harold G.

    2015-01-01

    Purpose To estimate the exchange rates of labile 1H in citrate and spermine, metabolites present in prostatic secretions, to predict the size of the citrate and spermine CEST effects in vivo. Methods CEST z‐spectra were acquired at high‐field [11.7 Tesla (T)] from citrate and spermine solutions at physiological pH (6.5) using saturation power 6 μT. CEST was performed at different temperatures to determine exchange regimes (slow, intermediate or fast). For low pH solutions of spermine, exchange rates were estimated from resonance line width, fitting z‐spectra using the Bloch equations incorporating exchange, and using quantifying exchange using saturation time experiments (QUEST). These rates were extrapolated to physiological pH. Results Citrate showed little CEST effect at pH 6.5 and temperature (T) = 310 K (maximum 0.001% mM‐1), indicating fast exchange, whereas spermine showed greater CEST effects (maximum 0.2% mM‐1) indicating intermediate‐to‐fast exchange. Extrapolating data acquired from low pH spermine solutions predicts exchange rates at pH 6.5 and T of 310 K of at least 2 × 104s‐1. Conclusion Citrate and spermine show minimal CEST effects at 11.7T even using high saturation power. These effects would be much less than 2% at clinical field‐strengths due to relatively faster exchange and would be masked by CEST from proteins. Magn Reson Med 76:742–746, 2016. © 2015 The Authors. Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. PMID:26467055

  16. Metformin-letrozole in comparison with Metformin-clomiphene citrate in clomiphene-resistance PCOS patients undergoing IUI

    Directory of Open Access Journals (Sweden)

    Mohammad Hossein Fallahzadeh

    2011-01-01

    Full Text Available Background: Polycystic ovary syndrome (PCOS is associated with approximately 75% of women who suffer from infertility due to anovulation. Additionally, around 20– 25% of anovulatory women with PCOS do not respond at all to clomiphene citrate and are considered to be “clomiphene– resistant”. Aromatase inhibitors have been suggested as an alternative treatment to clomiphene as the discrepancy between ovulation and pregnancy rates with clomiphene citrate has been attributed to its anti-estrogenic action and estrogen receptor depletion. Objective: The aim of this study is to compare results of Metformin-letrozole with Metformin-clomiphene citrate in clomiphene resistance PCOS patients undergoing IUI.Materials and Methods: In this single blind randomized trial, ovarian cycles were studied in 100 clomiphene- resistant patients with PCOS. The inclusion criteria were patients who received 150mg clomiphene citrate daily for 3 cycles and failed to become pregnant. The patients were matched for their age, body mass index (BMI, and infertility period. They were randomly allocated to a metformin-letrozole group (n=50 and a metformin-clomiphene citrate group (n=50. Chemical and clinical pregnancies were assessed after IUI. Abortion rates were determined in both groups. Results: Regarding pregnancy rate, there was no significant difference between the two groups. One miscarriage (2% occurred in the metformin-clomiphene citrate group, whereas none was seen in the metformin-letrozole group. Conclusion: There is no significant difference in pregnancy rate between clomiphene citrate and letrozole groups although it has been 2% in the former and 5% in the latter.

  17. Lattice Constant Dependence on Particle Size for Ceria prepared from a Citrate Sol-Gel

    International Nuclear Information System (INIS)

    Morris, V N; Farrell, R A; Sexton, A M; Morris, M A

    2006-01-01

    High surface area ceria nanoparticles have been prepared using a citrate solgel precipitation method. Changes to the particle size have been made by calcining the ceria powders at different temperatures, and X-ray methods used to determine their lattice parameters. The particle sizes have been assessed using transmission electron microscopy (TEM) and the lattice parameter found to fall with decreasing particle size. The results are discussed in the light of the role played by surface tension effects

  18. 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.

  19. Whole-body retention studies of /sup 169/Yb-citrate. Estimation of radiation dose to humans from /sup 169/Yb-citrate

    Energy Technology Data Exchange (ETDEWEB)

    Ando, A; Hiraki, T [Kanazawa Univ. (Japan). School of Paramedicine; Mori, H; Ando, I; Hisada, K

    1977-09-01

    For purpose of the estimation of the radiation dose to humans from /sup 169/Yb-citrate, the whole-body retention studies using five rats were carried out. Following intravenous administration of /sup 169/Yb-citrate, the whole-body activity was monitored for 40 days by the animal counter. The whole-body retention curve consisted of three components: the first with a 3.6 hours effective half-time, the second with an 154 hours effective half-time and the third with a 29.9 days effective half-time. Therefore it was assumed that 32% of the administered /sup 169/Yb-citrate clears from the kidney with a short biologic half-time (3.6 hours), 18% remains in the liver and other soft tissues with a relatively long biologic half-time (194 hours) and 50% remains in the bone with a long biologic half-time (850 days). Based on these biological data and the MIRD Committee method, the average dose to the bone and whole-body were 20.8 rads/mCi and 4.5 rads/mCi respectively.

  20. A Retrospective Review of the Use of Regional Citrate Anticoagulation in Continuous Venovenous Hemofiltration for Critically Ill Patients

    Directory of Open Access Journals (Sweden)

    Anne Kit-Hung Leung

    2013-01-01

    Full Text Available Background. The emergence of a commercially prepared citrate solution has revolutionized the use of RCA in the intensive care unit (ICU. The aim of this study was to evaluate the safety profile of a commercially prepared citrate solution. Method. Predilution continuous venovenous hemofiltration (CVVH was performed using Prismocitrate 10/2 at 2500 mL/h and a blood flow rate of 150 mL/min. Calcium chloride solution was infused to maintain ionized calcium within 1.0–1.2 mmol/L. An 8.4% sodium bicarbonate solution was infused separately. Treatment was stopped when the predefined clinical target was reached or the filter clotted. Result. 58 sessions of citrate RCA were analyzed. The median circuit lifetime was 26.0 h (interquartile range IQR 21.2–44.3. The percentage of circuits lasting more than 12 h, 24 h, and 48 h was 94.6%, 58.9%, and 16.1%, respectively. There was no incidence of hypernatremia and median pH was 2.5, only four patients had evidence of citrate accumulation. Conclusion. The commercially prepared citrate solution could be used safely in critically ill patients who required CVVH with no major adverse events.

  1. 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.

  2. On the nature of citrate-derived surface species on Ag nanoparticles: Insights from X-ray photoelectron spectroscopy

    Science.gov (United States)

    Mikhlin, Yuri L.; Vorobyev, Sergey A.; Saikova, Svetlana V.; Vishnyakova, Elena A.; Romanchenko, Alexander S.; Zharkov, Sergey M.; Larichev, Yurii V.

    2018-01-01

    Citrate is an important stabilizing, reducing, and complexing reagent in the wet chemical synthesis of nanoparticles of silver and other metals, however, the exact nature of adsorbates, and its mechanism of action are still uncertain. Here, we applied X-ray photoelectron spectroscopy, soft X-ray absorption near-edge spectroscopy, and other techniques in order to determine the surface composition and to specify the citrate-related species at Ag nanoparticles immobilized from the dense hydrosol prepared using room-temperature reduction of aqueous Ag+ ions with ferrous ions and citrate as stabilizer (Carey Lea method). It was found that, contrary to the common view, the species adsorbed on the Ag nanoparticles are, in large part, products of citrate decomposition comprising an alcohol group and one or two carboxylate bound to the surface Ag, and minor unbound carboxylate group; these may also be mixtures of citrate with lower molecular weight anions. No ketone groups were specified, and very minor surface Ag(I) and Fe (mainly, ferric oxyhydroxides) species were detected. Moreover, the adsorbates were different at AgNPs having various size and shape. The relation between the capping and the particle growth, colloidal stability of the high-concentration sol and properties of AgNPs is briefly considered.

  3. Chemical synthesis of nanocrystalline magnesium aluminate spinel via nitrate-citrate combustion route

    International Nuclear Information System (INIS)

    Saberi, Ali; Golestani-Fard, Farhad; Sarpoolaky, Hosein; Willert-Porada, Monika; Gerdes, Thorsten; Simon, Reinhard

    2008-01-01

    Nanocrystalline magnesium aluminate spinel (MgAl 2 O 4 ) was synthesized using metal nitrates, citric acid and ammonium solutions. The precursor and the calcined powders at different temperatures were characterized by X-ray diffraction (XRD), simultaneous thermal analysis (STA), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The combustion mechanism was also studied by a quadrupole mass spectrometer (QMS) which coupled to STA. The generated heat through the combustion of the mixture of ammonium nitrate and citrate based complexes decreased the synthesis temperature of MgAl 2 O 4 spinel. The synthesized MgAl 2 O 4 spinel at 900 deg. C has faced shape with crystallite size in the range of 18-24 nm

  4. 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.

  5. Sodium citrate-assisted anion exchange strategy for construction of Bi2O2CO3/BiOI photocatalysts

    International Nuclear Information System (INIS)

    Song, Peng-Yuan; Xu, Ming; Zhang, Wei-De

    2015-01-01

    Highlights: • Heterostructured Bi 2 O 2 CO 3 /BiOI microspheres were prepared via anion exchange. • Sodium citrate-assisted anion exchange for construction of composite photocatalysts. • Bi 2 O 2 CO 3 /BiOI composites show high visible light photocatalytic activity. - Abstract: Bi 2 O 2 CO 3 /BiOI heterojuncted photocatalysts were constructed through a facile partial anion exchange strategy starting from BiOI microspheres and urea with the assistance of sodium citrate. The content of Bi 2 O 2 CO 3 in the catalysts was regulated by modulating the amount of urea as a precursor, which was decomposed to generate CO 3 2− in the hydrothermal process. Citrate anion plays a key role in controlling the morphology and composition of the products. The Bi 2 O 2 CO 3 /BiOI catalysts display much higher photocatalytic activity than pure BiOI and Bi 2 O 2 CO 3 towards the degradation of rhodamine B (RhB) and bisphenol A (BPA). The enhancement of photocatalytic activity of the heterojuncted catalysts is attributed to the formation of p–n junction between p-BiOI and n-Bi 2 O 2 CO 3 , which is favorable for retarding the recombination of photoinduced electron-hole pairs. Moreover, the holes are demonstrated to be the main active species for the degradation of RhB and BPA

  6. Controlling Citrate Synthase Expression by CRISPR/Cas9 Genome Editing for n-Butanol Production in Escherichia coli

    DEFF Research Database (Denmark)

    Heo, Min-Ji; Jung, Hwi-Min; Um, Jaeyong

    2017-01-01

    Genome editing using CRISPR/Cas9 was successfully demonstrated in Esherichia coli to effectively produce n-butanol in a defined medium under microaerobic condition. The butanol synthetic pathway genes including those encoding oxygen-tolerant alcohol dehydrogenase were overexpressed in metabolically...... prediction program, UTR designer, and modified using the CRISPR/Cas9 genome editing method to reduce its expression level. E. coli strains with decreased citrate synthase expression produced more butanol and the citrate synthase activity was correlated with butanol production. These results demonstrate...

  7. 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.

  8. 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

  9. 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

  10. Calcium citrate: a new biomaterial that can enhance bone formation in situ

    Directory of Open Access Journals (Sweden)

    WANG Li-ming

    2012-11-01

    Full Text Available 【Abstract】 Objective: To investigate the effect of a new biomaterial combining calcium citrate and recombinant human bone morphogenetic protein-2 (rhBMP-2 on bone regeneration in a bone defect rabbit model. Methods: Totally 30 male New Zealand white rabbits were randomly and equally divided into calcium citrate-rhBMP-2 (CC-rhBMP-2 group and rhBMP-2 only group. Two 10 mm-long and 5 mm-deep bone defects were respec-tively created in the left and right femoral condyles of the rabbits. Subsequently 5 pellets of calcium citrate (10 mg combined with rhBMP-2 (2 mg or rhBMP-2 alone were im-planted into the bone defects and compressed with cotton swab. Bone granules were obtained at 2, 4 and 6 weeks after procedure and received histological analysis. LSD t-test and a subsequent t-test were adopted for statistical analysis. Results: Histomorphometric analysis revealed newly formed bones, and calcium citrate has been absorbed in the treatment group. The percent of newly formed bone area in femoral condyle in control group and CC-rhBMP-2 group was respectively 31.73%±1.26% vs 48.21%±2.37% at 2 weeks; 43.40%±1.65% vs 57.32%±1.47% at 4 weeks, and 51.32%±7.80% vs 66.74%±4.05% at 6 weeks (P<0.05 for all. At 2 weeks, mature cancellous bone was observed to be already formed in the treatment group. Conclusion: From this study, it can be concluded that calcium citrate combined with rhBMP-2 signifcantly en-hances bone regeneration in bone defects. This synthetic gelatin matrix stimulates formation of new bone and bone marrow in the defect areas by releasing calcium ions. Key words: Bone morphogenetic protein-2; Biocompatible materials; Calcium citrate; Gelatin

  11. Ytterbium 169 citrate in the diagnosis of lung opacities of cancerous origin

    International Nuclear Information System (INIS)

    Peltier, Patrick.

    1976-01-01

    Lung scintigraphy for tumour exploration has been widely studied for some years, but unfortunately with the many radioisotopes used at present this examination is not entirely reliable. It seemed interesting therefore to investigate a new tracer, 169 Yb citrate, the properties of which were demonstrated recently by HISADA. To estimate the specificity of this tracer we chose 62 records of different bronchopulmonary diseases. After an introductory review of various diagnostic methods the physical and physiological characteristics of ytterbium citrate and its method of use are described, then the records examined are presented and our thoughts and conclusions discussed. 169 Yb citrate possesses excellent biophysical properties for tumour scintigraphy but this isotope, though causing no radioactive pollution, delivers an appreciable irradiation dose to the patient examined. It has a positive tropism for pathological lung images. The fixation index of the documents taken separately, apart from that of the 14th day, cannot distinguish between benign and malignant diseases. This is possible with the kinetic uptake curve and the index ratios for the 2nd and 14th days. With these diagnostic criteria the overall results are better than those obtained with other commonly used radioisotopes: true positives 70%, false negatives 11%, false positives 4.5% [fr

  12. Preparation of freeze dried kit of sodium citrate labeled with Tc-99m used as a new kidney functional agent

    International Nuclear Information System (INIS)

    Merzah, K. S.; Abdulkrim, H. M.; Resen, H. M.; Badi, J. M.

    2012-12-01

    A new freeze-dried kit of sodium citrate complex has been prepared, to be labeled with technetium-99m can be used for diagnosis of kidney function. The labeling conditions of Tc-99m citrate complex using stannous chloride as a reducing agent for pertechnetate have been described. The GCS method reveals that the labeling efficiency of Tc-99m citrate complex is promoted by raisinng the pH of the preparation to (pH=4) using 1 N NaOH. The optimal amounts of the reactants in the preparation to obtain labeled and stable complex with high kidney uptake were found to be not less than (1 mg) sodium citrate and not more than (100μg) SnCI 2 2HO. The results show that high labeling yield (≥95%) for the labeled complex (Tc-99 Sn- citrate) can be perform due to the suitable reactant materials. The data of biodistribution experiments in the laboratory animals (Mice), clear high radioactivity accumulation labeled complex in kidney at 5 minutes post injection. The results of the radiochemical purity and biodistribution studies of the lyophilized kit approved that it was stable for about more than seven moths under normal conditions (2-8 o C ). The results of biodistribution of labeled kit have shown a good biological behavior with low radioactivity accumulation in the non-target organs (blood, liver and other organs). the aim of this study was to evaluate the potential of Tc-99-citrate complex as a new kidney functional agents and the efficiency of the freeze dried kit in the diagnosis of kidney function. (Author)

  13. Electrodialytic removal of heavy metals from municipal solid waste incineration fly ash using ammonium citrate as assisting agent

    DEFF Research Database (Denmark)

    Pedersen, Anne Juul; Ottosen, Lisbeth M.; Villumsen, Arne

    2005-01-01

    Electrodialytic remediation, an electrochemically assisted separation method, has previ-ously shown potential for removal of heavy metals from municipal solid waste incineration (MSWI) fly ashes. In this work electrodialytic remediation of MSWI fly ash using ammonium citrate as assisting agent...

  14. 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

  15. 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

  16. Synthesis of aluminum oxide by the polymer precursor method (Pechini) in 4: 1 ratio of citric acid: metal cation: calcination temperature effect

    International Nuclear Information System (INIS)

    Silva, M.C.; Lira, H.L.; Ribeiro, P.C.; Freitas, N.L.

    2014-01-01

    The technology field is nanopowders prominent in science since these materials fall in various sectors regarding their applications. This work aims at the synthesis of aluminum oxide by polymeric precursors in 4:1 ratio of citric acid:metal cation and evaluate the influence of calcination temperature on their structural and morphological characteristics. The samples after reaction were characterized by XRD and thermal analysis. After calcination 500-1200°C the samples were characterized by XRD, SEM and particle size distribution. The results showed that the variation of the calcination temperature is sufficient to achieve a same material with different structural and morphological characteristics. The most stable phase aluminum oxide arose only after calcination at 1100°C, below 900°C, the amorphous material appeared. As regards the morphology, the change was not as significant as compared to the structure. (author)

  17. Flexible biodegradable citrate-based polymeric step-index optical fiber.

    Science.gov (United States)

    Shan, Dingying; Zhang, Chenji; Kalaba, Surge; Mehta, Nikhil; Kim, Gloria B; Liu, Zhiwen; Yang, Jian

    2017-10-01

    Implanting fiber optical waveguides into tissue or organs for light delivery and collection is among the most effective ways to overcome the issue of tissue turbidity, a long-standing obstacle for biomedical optical technologies. Here, we report a citrate-based material platform with engineerable opto-mechano-biological properties and demonstrate a new type of biodegradable, biocompatible, and low-loss step-index optical fiber for organ-scale light delivery and collection. By leveraging the rich designability and processibility of citrate-based biodegradable polymers, two exemplary biodegradable elastomers with a fine refractive index difference and yet matched mechanical properties and biodegradation profiles were developed. Furthermore, we developed a two-step fabrication method to fabricate flexible and low-loss (0.4 db/cm) optical fibers, and performed systematic characterizations to study optical, spectroscopic, mechanical, and biodegradable properties. In addition, we demonstrated the proof of concept of image transmission through the citrate-based polymeric optical fibers and conducted in vivo deep tissue light delivery and fluorescence sensing in a Sprague-Dawley (SD) rat, laying the groundwork for realizing future implantable devices for long-term implantation where deep-tissue light delivery, sensing and imaging are desired, such as cell, tissue, and scaffold imaging in regenerative medicine and in vivo optogenetic stimulation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Sildenafil citrate protects skeletal muscle of ischemia-reperfusion injury: immunohistochemical study in rat model

    Directory of Open Access Journals (Sweden)

    Dinani Matoso Fialho de Oliveira Armstrong

    2013-04-01

    Full Text Available PURPOSE: To investigate the effect of sildenafil citrate (SC on skeletal muscle ischemia-reperfusion (IR injury in rats. METHODS: Adult male Wistar rats were randomized into three groups: vehicle-treated control (CTG, sildenafil citrate-treated (SCG, and sham group (SG. CTG and SCG had femoral artery occluded for 6 hours. Saline or 1 mg/kg of SC was given 5.5 hours after occlusion. SG had a similar procedure without artery occlusion. Soleus muscle samples were acquired 4 or 24h after the reperfusion. Immunohistochemistry caspase-3 analysis was used to estimate apoptosis using the apoptotic ratio (computed as positive/negative cells. Wilcoxon rank-sum or Kruskal-Wallis tests were used to assess differences among groups. RESULTS: Eighteen animals were included in the 4h reperfusion groups and 21 animals in the 24h reperfusion groups. The mean apoptotic ratio was 0.18±0.1 for the total cohort; 0.14±0.06 for the 4h reperfusion groups and 0.19±0.08 for the 24h groups (p<0.05. The SCG had lower caspase-3 ratio compared to the control groups at the 24h reperfusion time point (p<0.05. CONCLUSION: Sildenafil citrate administration after the onset of the ischemic injury reduces IR-induced cellular damage in skeletal muscle in this rat hindlimb ischemia model.

  19. Tofacitinib Citrate for Ulcerative Keratitis in a Patient with Rheumatoid Arthritis

    Directory of Open Access Journals (Sweden)

    Philip B. Meadow

    2014-01-01

    Full Text Available Purpose. To report a case of a patient with rheumatoid arthritis (RA treated with tofacitinib citrate. Methods. Observational case report. Results. A 59-year-old patient, with a history of rheumatoid arthritis, on methotrexate 10 mg PO qwk and IV abatacept 750 mg/month, presented with photosensitivity, foreign body sensation, pain, redness, and blurry vision of her right eye (RE. Visual acuity of the RE was 20/200 and 20/20 of the left eye (LE. The slit lamp examination of the RE revealed dryness, 2+ injection of the conjunctiva, and pericentral ulceration of the cornea with 20–30% stromal thinning, pannus, and diffuse punctate epithelial erosions. The anterior chamber appeared normal. Laboratory values revealed elevated levels of rheumatoid factor, anticyclic citrullinated peptide antibodies, and C-reactive protein. The patient was switched to tofacitinib citrate 5 mg PO b.i.d, underwent corneal gluing, and was given prednisone acetate 1% gt TID, polytrim gt TID, neomycin-polymyxin-dexameth gt QD, FreshKote lubricant 1.8% gt QID, moxifloxacin 0.5% gt QID, and preservative free artificial tears Q1H. Within one week, laboratory values normalized, symptoms diminished, and the cornea reepithelialized. Conclusion. RA can present with ulcerative keratitis. Tofacitinib citrate, steroids, and corneal gluing were found to halt the progression of keratolysis and promote reepithelialization.

  20. Development of biodegradable polymer based tamoxifen citrate loaded nanoparticles and effect of some manufacturing process parameters on them: a physicochemical and in-vitro evaluation

    Directory of Open Access Journals (Sweden)

    Basudev Sahana

    2010-08-01

    Full Text Available Basudev Sahana, Kousik Santra, Sumit Basu, Biswajit MukherjeeDepartment of Pharmaceutical Technology, Jadavpur University, Kolkata, IndiaAbstract: The aim of the present study was to develop nanoparticles of tamoxifen citrate, a non-steroidal antiestrogenic drug used for the treatment of breast cancer. Biodegradable poly (D, L- lactide-co-glycolide-85:15 (PLGA was used to develop nanoparticles of tamoxifen citrate by multiple emulsification (w/o/w and solvent evaporation technique. Drug-polymer ratio, polyvinyl alcohol concentrations, and homogenizing speeds were varied at different stages of preparation to optimize the desired size and release profile of drug. The characterization of particle morphology and shape was performed by field emission scanning electron microscope (FE-SEM and particle size distribution patterns were studied by direct light scattering method using zeta sizer. In vitro drug release study showed that release profile of tamoxifen from biodegradable nanoparticles varied due to the change in speed of centrifugation for separation. Drug loading efficiency varied from 18.60% to 71.98%. The FE-SEM study showed that biodegradable nanoparticles were smooth and spherical in shape. The stability studies of tamoxifen citrate in the experimental nanoparticles showed the structural integrity of tamoxifen citrate in PLGA nanoparticles up to 60°C in the tested temperatures. Nanoparticles containing tamoxifen citrate could be useful for the controlled delivery of the drug for a prolonged period.Keywords: biodegradable, nanoparticles, PLGA, stability, tamoxifen citrate

  1. Thin film solar cells by selenization sulfurization using diethyl selenium as a selenium precursor

    Science.gov (United States)

    Dhere, Neelkanth G.; Kadam, Ankur A.

    2009-12-15

    A method of forming a CIGSS absorber layer includes the steps of providing a metal precursor, and selenizing the metal precursor using diethyl selenium to form a selenized metal precursor layer (CIGSS absorber layer). A high efficiency solar cell includes a CIGSS absorber layer formed by a process including selenizing a metal precursor using diethyl selenium to form the CIGSS absorber layer.

  2. 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.

  3. 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.

  4. Nanosized Ni-Mn Oxides Prepared by the Citrate Gel Process and Performances for Electrochemical Capacitors

    Institute of Scientific and Technical Information of China (English)

    Jianxin ZHOU; Xiangqian SHEN; Maoxiang JING

    2006-01-01

    Nanosized Ni-Mn oxide powders have been successfully prepared by thermal decomposition of the Ni-Mn citrate gel precursors. The powder materials derived from calcination of the gel precursors with various molar ratios of nickel and manganese at different temperatures and time were characterized using thermal analysis (TG-DSC), scanning electron microscopy (SEM), X-ray diffraction (XRD) and Brunauer-Emmet-Teller (BET).The optimized processing conditions of calcination at 400℃ for 1 h with Ni/Mn molar ratio 6 were proved to produce the nanosized Ni-Mn oxide powders with a high specific surface area of 109.62 m2/g and nanometer particle sizes of 15~30 nm. The capacitance characteristics of the nanosized Ni-Mn oxide electrode in various concentrations of KOH solutions were studied by the cyclic voltammetry (CV) and exhibited both a doublelayer capacitance and a Faradaic capacitance which could be attributed to the electrode consisting of Ni-Mn oxides and residual carbons from the organic gel thermal decomposition. A specific capacitance of 194.8 F/g was obtained for the electrode at the sweep rate of 10 mV/s in 4 mol/L KOH electrolyte and the capacitor showed quite high cyclic stability and is promising for advanced electrochemical capacitors.

  5. Influence of Cobalt Precursor on Efficient Production of Commercial Fuels over FTS Co/SiC Catalyst

    Directory of Open Access Journals (Sweden)

    Ana Raquel de la Osa

    2016-07-01

    Full Text Available β-SiC-supported cobalt catalysts have been prepared from nitrate, acetate, chloride and citrate salts to study the dependence of Fischer–Tropsch synthesis (FTS on the type of precursor. Com/SiC catalysts were synthetized by vacuum-assisted impregnation while N2 adsorption/desorption, XRD, TEM, TPR, O2 pulses and acid/base titrations were used as characterization techniques. FTS catalytic performance was carried out at 220 °C and 250 °C while keeping constant the pressure (20 bar, space velocity (6000 Ncm3/g·h and syngas composition (H2/CO:2. The nature of cobalt precursor was found to influence basic behavior, extent of reduction and metallic particle size. For β-SiC-supported catalysts, the use of cobalt nitrate resulted in big Co crystallites, an enhanced degree of reduction and higher basicity compared to acetate, chloride and citrate-based catalysts. Consequently, cobalt nitrate provided a better activity and selectivity to C5+ (less than 10% methane was formed, which was centered in kerosene-diesel fraction (α = 0.90. On the contrary, catalyst from cobalt citrate, characterized by the highest viscosity and acidity values, presented a highly dispersed distribution of Co nanoparticles leading to a lower reducibility. Therefore, a lower FTS activity was obtained and chain growth probability was shortened as observed from methane and gasoline-kerosene (α = 0.76 production when using cobalt citrate.

  6. Structural and morphological characterization of TiO{sub 2}-ZrO{sub 2} powders obtained by the polymeric precursors method; Caracterizacao estrutural e morfologica de pos de TiO{sub 2}-ZrO{sub 2} obtidos pelo metodo dos precursores polimericos

    Energy Technology Data Exchange (ETDEWEB)

    Ribeiro, M.A.; Gama, L.; Bispo, A.; Neiva, L.S., E-mail: m_aparecidaribeiro@yahoo.com.b [Universidade Federal de Campina Grande (DEMa/UFCG), PB (Brazil). Dept. de Engenharia de Materiais; Bernardi, M.I.B. [Universidade de Sao Paulo (IFSC/USP), Sao Carlos, SP (Brazil). Inst. de Fisica; Kiminami, R.H.G.A. [Universidade Federal de Sao Carlos (DEMa/UFSCar), SP (Brazil). Dept. de Engenharia de Materiais

    2010-07-01

    This work aims to characterize the structure and morphology of TiO{sub 2}-ZrO{sub 2} powders obtained by polymeric precursor method. For this we studied the following compositions: 0.25, 0.5 and 0.75 moles of Zr and calcined at 800 deg C for one hour. The powders obtained were characterized by XRD, SEM and nitrogen adsorption (BET). The analysis of X-ray diffraction showed that the powders had a phase of TiO{sub 2} in the anatase form and a tetragonal phase of ZrO{sub 2}. The crystallite size was between 8, 13 and 11 nm respectively. The analysis of scanning electron microscopy showed the growth of ZrO{sub 2} nanoparticles and that these comprise spherical agglomerates of less than 100 nm. Particle size determined by the BET ranging 28.1-29.5 nm, showing thereby the character of nanosized powders. (author)

  7. 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.

  8. Radiochemical Means of Investigating Delayed Neutron Precursors

    International Nuclear Information System (INIS)

    Marmol, P. del

    1968-01-01

    Fast radiochemical methods used now for the determination of delayed neutron precursors are classified and reviewed: precipitations, solvent extractions, range experiments, milking, gas sweeping, isotopic and ion exchange, hot atom reactions and diffusion loss. Advantages and limitations of irradiation systems with respect to fast separations are discussed: external beams which allow faster separations only have low neutron fluxes, internal beams which are mostly fit for gaseous reactions; and rabbits for solution irradiations. Future prospects of radiochemical procedures are presented; among these, studies should be mostly oriented towards gaseous reactions which offer possibilities of isolating very short-lived delayed neutron precursors. Chemical procedures for delayed neutron precursor detection are compared with mass spectrometric and isotope separator techniques; it is concluded that the methods are complementary. (author)

  9. Radiochemical Means of Investigating Delayed Neutron Precursors

    International Nuclear Information System (INIS)

    Marmol, P. del

    1968-01-01

    Fast radiochemical methods used now for the determination of delayed neutron precursors are classified and reviewed: precipitations, solvent extractions, range experiments, milking, gas sweeping, isotopic and ion exchange, hot-atom reactions and diffusion loss. Advantages and limitations of irradiation systems with respect to fast separations are discussed: external beams which allow faster separations only have low neutron fluxes, internal beams which are mostly fit for gaseous reactions; and rabbits for solution irradiations. Future prospects of radiochemical procedures are presented; among these, studies should be mostly oriented towards gaseous reactions which offer possibilities of isolating very short-lived delayed neutron precursors. Chemical procedures for delayed neutron precursor detection are compared with mass spectrometric and isotope-separator techniques; it is concluded that the methods are complementary. (author)

  10. Geometrizing configurations. Heinrich Hertz and his mathematical precursors

    DEFF Research Database (Denmark)

    Lützen, Jesper

    1999-01-01

    A comparison between the methods used by Heinrich hertz and his mathematician precursors such as Liouville, Lipschitz and Darboux in order to apply differential geometry in mechanics......A comparison between the methods used by Heinrich hertz and his mathematician precursors such as Liouville, Lipschitz and Darboux in order to apply differential geometry in mechanics...

  11. Citrate dialysate does not induce oxidative stress or inflammation in vitro as compared to acetate dialysate

    Directory of Open Access Journals (Sweden)

    Rafael Pérez-García

    2017-11-01

    Full Text Available Increased acetataemia during haemodialysis sessions has been associated with a number of abnormalities, including increased oxidative stress, pro-inflammatory cytokines and nitric oxide synthesis. Citric acid may play an alternative role to acetate as a dialysate stabilizer given that the effect of citrate on complement and leukocyte activation is different to that of acetate. The purpose of this study was to compare the inflammatory effect in immunocompetent blood cells of acetate dialysate and citrate dialysate. Materials and methods: The effect of acetate and/or citrate was investigated in the whole blood of uremic patients and in healthy in vitro samples. Four types of dialysate were tested: dialysate 1, acetate-free with 1 mmol/L of citrate; dialysate 2, with 0.8 mmol/L of citrate and 0.3 mmol/L of acetate; dialysate 3, citrate-free with 3 mmol/L of acetate; and dialysate 4, citrate-free with 4 mmol/L of acetate. The cell types used were: human monocyte culture (THP-1; and peripheral blood mononuclear cells (PBMCs from healthy subjects and uremic patients on haemodialysis. ICAM-1 was determined and levels of reactive oxygen species and total microvesicles were quantified. Results: Unlike the citrate dialysates, the dialysates with acetate (dialysate 3 and dialysate 4 induced increased ICAM-1 expression density in THP-1 cells; an increase in ICAM-1 expression was observed in the immunocompetent cells of healthy subjects with acetate dialysate (dialysate 3 and dialysate 4 but not with citrate dialysate (dialysate 1 and dialysate 2. No significant ICAM-1 differences were found between the different dialysates in the cells of haemodialysed patients. Reactive oxygen species expression and the number of microvesicles increased significantly with acetate dialysate but not with citrate dialysate in the cells of both healthy subjects and haemodialysed patients. Conclusion: At the concentrations in which it is generally used in clinical practice

  12. The impact of TEL-AML1 (ETV6-RUNX1) expression in precursor B cells and implications for leukaemia using three different genome-wide screening methods

    International Nuclear Information System (INIS)

    Linka, Y; Ginzel, S; Krüger, M; Novosel, A; Gombert, M; Kremmer, E; Harbott, J; Thiele, R; Borkhardt, A; Landgraf, P

    2013-01-01

    The reciprocal translocation t(12;21)(p13;q22), the most common structural genomic alteration in B-cell precursor acute lymphoblastic leukaemia in children, results in a chimeric transcription factor TEL-AML1 (ETV6-RUNX1). We identified directly and indirectly regulated target genes utilizing an inducible TEL-AML1 system derived from the murine pro B-cell line BA/F3 and a monoclonal antibody directed against TEL-AML1. By integration of promoter binding identified with chromatin immunoprecipitation (ChIP)-on-chip, gene expression and protein output through microarray technology and stable labelling of amino acids in cell culture, we identified 217 directly and 118 indirectly regulated targets of the TEL-AML1 fusion protein. Directly, but not indirectly, regulated promoters were enriched in AML1-binding sites. The majority of promoter regions were specific for the fusion protein and not bound by native AML1 or TEL. Comparison with gene expression profiles from TEL-AML1-positive patients identified 56 concordantly misregulated genes with negative effects on proliferation and cellular transport mechanisms and positive effects on cellular migration, and stress responses including immunological responses. In summary, this work for the first time gives a comprehensive insight into how TEL-AML1 expression may directly and indirectly contribute to alter cells to become prone for leukemic transformation

  13. A new method to measure muscle protein synthesis in humans by endogenously introduced d9-leucine and using blood for precursor enrichment determination

    Science.gov (United States)

    Tran, Lee; Masters, Haley; Roust, Lori R; Katsanos, Christos S

    2015-01-01

    Enrichment from the easily accessible blood amino acid pool is commonly used as precursor enrichment to calculate rates of muscle protein fractional synthesis in relevant human studies in lieu of the less accessible muscle fluid amino acid pool. However, the accuracy of this approach depends largely on the extent to which there is low discrepancy in free amino acid enrichment between blood and muscle. Steady-state gradient (i.e., ratio) of amino acid enrichment between blood and muscle fluid in the basal state and in response to amino acid infusion were determined in five healthy subjects, and in association with two separate tracers: d9-leucine, introduced endogenously by the metabolism of d10-leucine (i.e., l-[2,3,3,4,5,5,5,6,6,6-2H10]leucine) infused in blood, and 13C6-phenylalanine introduced/infused in blood. The blood-to-muscle fluid amino acid enrichment ratio was lower (P enrichment introduced endogenously by intravenous infusion of d10-leucine provides a closer estimate of the muscle fluid amino acid enrichment, and its associated changes, than blood phenylalanine enrichment to calculate rates of muscle protein synthesis in humans. PMID:26243214

  14. 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).

  15. Reduction of costs for anemia-management drugs associated with the use of ferric citrate

    Directory of Open Access Journals (Sweden)

    Thomas A

    2014-05-01

    Full Text Available Anila Thomas,1 Leif E Peterson2 1Clinical Pharmacy Services, Houston Methodist Hospital, Houston, TX, USA; 2Center for Biostatistics, Houston Methodist Research Institute, Houston, TX, USA Background: Ferric citrate is a novel phosphate binder which has the potential to reduce usage of erythropoietin-stimulating agents (ESAs and intravenous (IV iron used for anemia management during hemodialysis (HD among patients with end-stage renal disease (ESRD. Currently, the potential health care cost savings on a national scale due to the use of ferric citrate in ESRD are undetermined. Methods: Per-patient-per-year costs of ESAs (Epogen® and Aranesp® [Amgen Inc., CA, USA] and IV iron (Venofer® [American Regent, Inc., NY, USA] and Ferrlecit® [Sanofi US, Bridgewater, NJ, USA] were based on RED BOOK™ (Truven Health Analytics New York, NY, USA costs combined with the Centers for Medicare and Medicaid Services (CMS base rate and actual usage in 2011 for the four drugs. The annual number of outpatients undergoing HD in the US was based on frequencies reported by the USRDS (United States Renal Data System. Monte Carlo uncertainty analysis was performed to determine total annual costs and cost reduction based on ferric citrate usage. Results: Total annual cost of ESAs and IV iron for anemia management in ESRD determined by Monte Carlo analysis assuming CMS base rate value was 5.127 (3.664–6.260 billion USD. For actual utilization in 2011, total annual cost of ESAs and IV iron was 3.981 (2.780–4.930 billion USD. If ferric citrate usage reduced ESA utilization by 20% and IV iron by 40%, then total cost would be reduced by 21.2% to 4.038 (2.868–4.914 billion USD for the CMS base rate, and by 21.8% to 3.111 (2.148–3.845 billion USD, based on 2011 actual utilization. Conclusion: It is likely that US health care costs for anemia-management drugs associated with ESRD among HD patients can be reduced by using ferric citrate as a phosphate binder. Keywords

  16. Study of corrosion behavior on the addition of sodium citrate in nickel electroplating on SPCC steel using EIS

    Science.gov (United States)

    Riastuti, R.; Ramadini, C.; Siallagan, S. T.; Rifki, A.; Herdino, F.

    2018-04-01

    The addition of sodium citrate to nickel electroplating process as additive is useful for refining the grain size of nickel deposit. The refining of grain size in nickel deposit as coating layer can improve surface performance, one of which corrosion resistance. This paper aims to investigate the effect of sodium citrate addition as grain refiner to promote corrosion resistance on SPCC steel. This experiment used Watt’s Bath solution of NiSO4 300 g/L, NiCl4 45 g/L, H3BO3 60 g/L, wetting agent 0.2 cc/L. Sodium citrate was added in composition of 45g/L and 60g/L. Nickel were deposited by direct current using current density on 6 A/dm2 at the acidity level of 5 for 30 minutes by keeping the operating temperature stable at 50°C. The grain size of nickel deposit was observed through Optical Microscope and Atomic Force Microscope (AFM). The corrosion behavior of SPCC was observed by linear polarization and Electrochemical Impedance Spectroscopy (EIS) methods using 3% NaCl solution. Based on the research, the addition of sodium citrate as grain refiner will increasing corrosion resistance on SPCC steel from 0.35 to 0.05 mm/year.

  17. 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.

  18. 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.

  19. Lessons learned on probabilistic methodology for precursor analyses

    International Nuclear Information System (INIS)

    Babst, Siegfried; Wielenberg, Andreas; Gaenssmantel, Gerhard

    2016-01-01

    Based on its experience in precursor assessment of operating experience from German NPP and related international activities in the field, GRS has identified areas for enhancing probabilistic methodology. These are related to improving the completeness of PSA models, to insufficiencies in probabilistic assessment approaches, and to enhancements of precursor assessment methods. Three examples from the recent practice in precursor assessments illustrating relevant methodological insights are provided and discussed in more detail. Our experience reinforces the importance of having full scope, current PSA models up to Level 2 PSA and including hazard scenarios for precursor analysis. Our lessons learned include that PSA models should be regularly updated regarding CCF data and inclusion of newly discovered CCF mechanisms or groups. Moreover, precursor classification schemes should be extended to degradations and unavailabilities of the containment function. Finally, PSA and precursor assessments should put more emphasis on the consideration of passive provisions for safety, e. g. by sensitivity cases.

  20. Lessons learned on probabilistic methodology for precursor analyses

    Energy Technology Data Exchange (ETDEWEB)

    Babst, Siegfried [Gesellschaft fuer Anlagen- und Reaktorsicherheit (GRS) gGmbH, Berlin (Germany); Wielenberg, Andreas; Gaenssmantel, Gerhard [Gesellschaft fuer Anlagen- und Reaktorsicherheit (GRS) gGmbH, Garching (Germany)

    2016-11-15

    Based on its experience in precursor assessment of operating experience from German NPP and related international activities in the field, GRS has identified areas for enhancing probabilistic methodology. These are related to improving the completeness of PSA models, to insufficiencies in probabilistic assessment approaches, and to enhancements of precursor assessment methods. Three examples from the recent practice in precursor assessments illustrating relevant methodological insights are provided and discussed in more detail. Our experience reinforces the importance of having full scope, current PSA models up to Level 2 PSA and including hazard scenarios for precursor analysis. Our lessons learned include that PSA models should be regularly updated regarding CCF data and inclusion of newly discovered CCF mechanisms or groups. Moreover, precursor classification schemes should be extended to degradations and unavailabilities of the containment function. Finally, PSA and precursor assessments should put more emphasis on the consideration of passive provisions for safety, e. g. by sensitivity cases.

  1. 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...

  2. Enhanced electrochemical performance of different morphological C/LiMnPO4 nanoparticles from hollow-sphere Li3PO4 precursor via a delicate polyol-assisted hydrothermal method

    Science.gov (United States)

    Cui, Yu-Ting; Xu, Ning; Kou, Li-Qin; Wu, Meng-Tao; Chen, Li

    2014-03-01

    With the hollow-sphere Li3PO4 as precursor, a delicate polyol-assisted hydrothermal method is devised to synthesize high-performance LiMnPO4. Orthorhombic shaped, irregular flaky shaped and sphere-like LiMnPO4 are sequentially prepared by decreasing the water-diethylene glycol (DEG) ratio. The capacity, cycling stability and rate performance of all samples prepared by the new synthesis method are improved significantly. And the C/LiMnPO4 with irregular flaky shape exhibits a capacity of 154.1 mA h g-1 at C/20, 147.4 mA h g-1 at C/10 and 102.5 mA h g-1 at 2 C, which is the best performance ever reported for LiMnPO4 active material with similar carbon additives.

  3. 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...

  4. 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)

  5. 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...

  6. 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 ...

  7. 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.

  8. Comparison of equine platelet function and survival in whole blood collected in acid-citrate-dextrose solution or citrate-phosphate-dextrose-adenine solution.

    Science.gov (United States)

    Bozorgmanesh, Rana; Sutton-Burges, Julie W; Tablin, Fern

    2017-06-01

    Equine whole blood collection and storage methods have been evaluated to assess red blood cell viability; however, platelet (PLT) viability has not been comprehensively assessed. The purpose of the study was to compare viability of PLTs collected in whole blood into 2 different anticoagulants. Whole blood from 6 healthy adult Thoroughbred horses was collected into citrate-phosphate-dextrose-adenine (CPDA) or acid-citrate-dextrose (ACD). Platelet count, pH, and concentrations of glucose, lactate, carbon dioxide, oxygen, bicarbonate, sodium, potassium, and chloride were measured within 10 minutes of collection and then again one hour later at which time PLT aggregometry was performed to assess PLT function. Aggregometry mean amplitudes were significantly higher in CPDA compared to ACD. Blood glucose, pH, bicarbonate, sodium, and lactate concentrations were significantly higher in CPDA compared to ACD. Lactate concentration was higher following one hour in either anticoagulant. Potassium, oxygen, and carbon dioxide concentrations were significantly higher in ACD compared to CPDA at collection. Platelet aggregometry results suggest that CPDA is superior to ACD for maintaining PLT viability following whole blood collection. This may be associated with the higher, more neutral pH as well as an increase in glucose available for metabolism. Although lactate was increased in the CPDA samples it was not high enough to decrease pH and therefore may not have been high enough to cause morphologic lesions and loss of PLT viability. © 2017 American Society for Veterinary Clinical Pathology.

  9. A Comparative 68Ga-Citrate and 68Ga-Chloride PET/CT Imaging of Staphylococcus aureus Osteomyelitis in the Rat Tibia

    Directory of Open Access Journals (Sweden)

    Petteri Lankinen

    2018-01-01

    Full Text Available There may be some differences in the in vivo behavior of 68Ga-chloride and 68Ga-citrate leading to different accumulation profiles. This study compared 68Ga-citrate and 68Ga-chloride PET/CT imaging under standardized experimental models. Methods. Diffuse Staphylococcus aureus tibial osteomyelitis and uncomplicated bone healing rat models were used (n=32. Two weeks after surgery, PET/CT imaging was performed on consecutive days using 68Ga-citrate or 68Ga-chloride, and tissue accumulation was confirmed by ex vivo analysis. In addition, peripheral quantitative computed tomography and conventional radiography were performed. Osteomyelitis was verified by microbiological analysis and specimens were also processed for histomorphometry. Results. In PET/CT imaging, the SUVmax of 68Ga-chloride and 68Ga-citrate in the osteomyelitic tibias (3.6 ± 1.4 and 4.7 ± 1.5, resp. were significantly higher (P=0.0019 and P=0.0020, resp. than in the uncomplicated bone healing (2.7 ± 0.44 and 2.5 ± 0.49, resp.. In osteomyelitic tibias, the SUVmax of 68Ga-citrate was significantly higher than the uptake of 68Ga-chloride (P=0.0017. In animals with uncomplicated bone healing, no difference in the SUVmax of 68Ga-chloride or 68Ga-citrate was seen in the operated tibias. Conclusions. This study further corroborates the use of 68Ga-citrate for PET imaging of osteomyelitis.

  10. 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

  11. A liquid chromatography-tandem mass spectrometry method for simultaneous analysis of acrylamide and the precursors, asparagine and reducing sugars in bread

    DEFF Research Database (Denmark)

    Nielsen, N.J.; Granby, Kit; Hedegaard, Rikke Susanne Vingborg

    2006-01-01

    A LC-MS-MS method for simultaneous determination of acrylamide, asparagine, fructose, glucose and sucrose in bread was developed. The method is based on aqueous extraction by blending. After centrifugation the samples were cleaned up by solid phase extraction on C18 cartridges conditioned with 2 ...

  12. Effects of Citrate and Arginine on Sorption of Nickel to Yazd Sepiolite and Calcite

    Directory of Open Access Journals (Sweden)

    Ahmadreza Sheikhhosseini

    2017-03-01

    Full Text Available Introduction: Pollution of soil and water environment by release of heavy metals is of great concerns of the last decades. Sorption of heavy metals by low cost materials is considered as an inexpensive and efficient method used for removal of heavy metals from soil-water systems. The presence of different ligands with various complexing abilities can change the sorption properties of heavy metals and their fate in the environment as well. In order to assess the effect of citrate and arginine as natural organic ligands in soil environment, in a batch study we investigated the effects of these ligands on equilibrium sorption of nickel to sepiolite and calcite minerals and also kinetics of Ni sorption by these minerals. Materials and Methods: Minerals used in this study included sepiolite from Yazd (Iran and pure calcite (Analytical grade, Merck, Germany. Sepiolite was purified, saturated with Ca using 0.5 M CaCl2, powdered in a mortar and sieved by non-metal 230 mesh standard wire sieve. For equilibrium sorption study, in a 50-mL polyethylene centrifuge tube,0.3 g sample of each mineral was suspended in 30 mL of a 0.01 M CaCl2 solution containing 0, 5, 10, 20, 40, 60, 80 and 100 mg L-1 Ni (NiCl2 and containing zero (as control or 0.1mmol L-1 citrate or arginine ligands. The applied concentrationsfor each ligand can naturally occur in soils. Preparedtubes were shaken (180±2 rpm, 25±1oC for 24 h using an orbital shaker and centrifuged (4000×g for 10 min and the supernatants were analyzed for Ni concentration using an atomic absorption spectrophotometer (AAnalyst 200 Perkin-Elmer at a wavelength of 232 nm and a detection limit of 0.05 mg L-1. The quantity of Ni retained by each mineral at equilibrium was calculated using equation qe = (Ci - CeV/W where qe was the amount of nickel retained by mineral surface at equilibrium. Ci and Ce were the initial and the equilibrium concentrations (mg L-1 of Ni, respectively, V was the volume (L of the solution

  13. 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.

  14. Catalytic oxidation of n-hexane promoted by Ce{sub 1−x}Cu{sub x}O{sub 2} catalysts prepared by one-step polymeric precursor method

    Energy Technology Data Exchange (ETDEWEB)

    Araújo, Vinícius D., E-mail: dantas@ursa.ifsc.usp.br [Instituto de Física, Universidade de São Paulo – USP, 13560-970 São Carlos, SP (Brazil); Lima, Maurício M. de [Instituto de Ciencia de los Materiales, Universidad de Valencia, E-46071 Valencia (Spain); Fundación General, Universitat de Valencia, Valencia (Spain); Cantarero, Andrés [Instituto de Ciencia de los Materiales, Universidad de Valencia, E-46071 Valencia (Spain); Bernardi, Maria I.B. [Instituto de Física, Universidade de São Paulo – USP, 13560-970 São Carlos, SP (Brazil); Bellido, Jorge D.A. [CAP-Engenharia Química, Universidade Federal de São João Del-Rei – UFSJ, São João Del-Rei, MG (Brazil); Assaf, Elisabete M. [Instituto de Química, Universidade de São Paulo – USP, 13560-970 São Carlos, SP (Brazil); Balzer, Rosana; Probst, Luiz F.D. [Departamento de Química, Universidade Federal de Santa Catarina – UFSC, 88040-900 Florianópolis, SC (Brazil); Fajardo, Humberto V. [Departamento de Química, Universidade Federal de Ouro Preto – UFOP, 35400-000 Ouro Preto, MG (Brazil)

    2013-11-01

    Ceria-supported copper catalysts (Ce{sub 1−x}Cu{sub x}O{sub 2}, with x (mol) = 0, 0.01, 0.03, 0.05 and 0.10) were prepared in one step through the polymeric precursor method. The textural properties of the catalysts were investigated by X-ray diffraction (XRD), Rietveld refinement, N{sub 2}-physisorption (BET surface area), electron paramagnetic resonance (EPR), UV–visible diffuse reflectance and photoluminescence spectroscopies and temperature-programmed reduction (TPR). In a previous study ceria-supported copper catalysts were found to be efficient in the preferential oxidation of CO. In this study, we extended the catalytic application of Ce{sub 1−x}Cu{sub x}O{sub 2} systems to n-hexane oxidation and it was verified that the catalysts were highly efficient in the proposed reaction. The best performance (up to 95% conversion) was observed for the catalysts with low copper loads (Ce{sub 0.97}Cu{sub 0.03}O{sub 2} and Ce{sub 0.99}Cu{sub 0.01}O{sub 2}, respectively). The physicochemical characterizations revealed that these behaviors could be attributed to the copper species present in the catalysts and the interaction between CuO and CeO{sub 2}, which vary according to the copper content. - Highlights: • Synthesis of CuO/CeO2 catalysts by the one-step polymeric precursor method. • 95% n-hexane conversion on Ce0.97Cu0.03O2 catalyst. • Redox properties play a key role in the catalytic performance.

  15. Efeito do vapor d'água na síntese pelo método do precursor polimérico da alumina contendo aditivos Effect of water vapor on the synthesis by the polymeric precursor method of alumina doped powders

    Directory of Open Access Journals (Sweden)

    R. H. R. Castro

    2005-12-01

    Full Text Available A presença de H2O nos processos de síntese e transformação de fase da alumina tem usualmente função catalisadora, diminuindo as temperaturas dos processos e facilitando os possíveis rearranjos atômicos. Neste trabalho mostrou-se que o vapor de H2O durante a síntese pode não apenas acelerar os processos diminuindo as energias de ativação, mas também induzir diferentes formas de ação de aditivos. O estudo foi possível utilizando-se o método dos precursores poliméricos para a síntese dos pós, que permite um controle absoluto do teor de H2O na etapa de cristalização do material. Alumina contendo Mn ou Mg como aditivos foram sintetizadas na ausência de H2O e na presença de excesso controlado desta e fases diferentes para cada situação foram observadas. Uma explicação do fenômeno é descrita em função da dependência da cristalização da gama-Al2O3 na presença de H+ para compensação das vacâncias catiônicas.It is commonly accepted that the presence of H2O during the synthesis and phase transformation of alumina causes decreasing temperatures of these processes since it increases the atomic motilities. In addition to this general concept, in this work H2O vapor is also shown to play an important role on the influence of additives in alumina based systems. Alumina powders containing Mn or Mg were synthesized by the polymeric precursor method under H2O vapor or dry atmosphere during the crystallization stage. Each atmosphere promoted a different phase and an explanation for the phenomenon was given bases on the gamma-Al2O3 crystallization dependence on the H+ presence due to the required cationic vacancies compensations.

  16. Effect of sildenafil citrate on women affected by sexual dysfunction referred to health clinics

    Directory of Open Access Journals (Sweden)

    Sanaz Zeinalzadeh

    2017-06-01

    Full Text Available Background. Female sexual dysfunction is a serious, multifactorial problem which affects women’s quality of life. Objectives. This study aimed at assessing the effect of sildenafil citrate on sexual dysfunction among women of reproductive age. Materials and methods. The present randomized clinical trial was conducted on 84 married women between 18 and 40 years old who suffered from sexual dysfunction. The inclusion criteria of the study were being married and between 18–40 years old, obtaining scores ≥ 22 in FSFI, not having a history of hypothyroidism or hyperprolactinemia, and not suffering from dyspareunia or vaginismus. The intervention group was required to consume 50 mg sildenafil citrate 1 hour before sexual intercourse for 5 weeks, and the control group received placebo. FSFI was completed by both study groups before and 5 weeks after the treatment. The data were analyzed through SPSS (v. 18 and paired t-test and independent t-test. Results . Most of the women (67.2% were between 30 and 40 years old. The study results revealed a significant difference between the two groups regarding the mean scores of sexual desire (p = 0.011, sexual arousal (p = 0.001, lubrication (p = 0.026, orgasm and sexual satisfaction (p < 0.001, and the whole dimension (p < 0.001. Besides, total mean sexual function before and after for the intervention and control groups was 21.1 ± 3.28 vs. 17.22 ± 5.9 (p < 0.001. Conclusion . In this study, sildenafil citrate was effective in enhancing sexual desire, arousal, orgasm, and sexual satisfaction. Of course, more studies need to be conducted on this issue.

  17. Ferric ammonium citrate as a positive bowel contrast agent for MR imaging of the upper abdomen

    Energy Technology Data Exchange (ETDEWEB)

    Kivelitz, D.; Taupitz, M.; Hamm, B. [Universitaetsklinikum Charite, Berlin (Germany). Inst. fuer Radiologie; Gehl, H.B. [Medizinische Univ. Luebeck (Germany). Inst. fuer Radiologie; Heuck, A. [Muenchen Univ. (Germany). Radiologische Klinik; Krahe, T. [Koeln Univ. (Germany). Inst. fuer Radiologische Diagnostik; Lodemann, K.P. [Bracco-Byk Gulden GmbH, Konstanz (Germany)

    1999-07-01

    Purpose: To evaluate the safety and diagnostic efficacy of two different doses of ferric ammonium citrate as a paramagnetic oral contrast agent for MR imaging of the upper abdomen. Material and methods: Ninety-nine adult patients referred for MR imaging for a known or suspected upper abdominal pathology were included in this randomized multicenter double-blind clinical trial. Imaging was performed with spin-echo (T1- and T2-weighted) and gradient-echo (T1-weighted) techniques before and after administration of either 1200 mg or 2400 mg of ferric ammonium citrate dissolved in 600 ml of water. Safety analysis included monitoring of vital signs, assessment of adverse events, and laboratory testing. Efficacy with regard to organ distension, contrast distribution, bowel enhancement and delineation of adjacent structures was graded qualitatively. Results: No serious adverse events were reported for either of the two concentrations. A total of 31 minor side effects were noted, of which significantly more occurred in the higher dose group (p<0.01). The diagnostic confidence in defining or excluding disease was graded as better after contrast administration for 48% of all images. Marked or moderate enhancement of the upper gastrointestinal tract was achieved at both doses in 69.5% of cases with no evident difference between the two doses. The higher dose tended to show better results in terms of the contrast assessment parameters. Conclusion: Ferric ammonium citrate is a safe and effective oral contrast agent for MR imaging of the upper abdomen at two different dose levels. The higher dose showed a tendency toward better imaging results while the lower dose caused significantly fewer side effects. Therefore, the 1200 mg dose can be recommended in view of the risk-to-benefit ratio. (orig.)

  18. Report on Fukushima Daiichi NPP precursor events

    International Nuclear Information System (INIS)

    2014-01-01

    The main questions to be answered by this report were: The Fukushima Daiichi NPP accident, could it have been prevented? If there is a next severe accident, may it be prevented? To answer the first question, the report addressed several aspects. First, the report investigated whether precursors to the Fukushima Daiichi NPP accident existed in the operating experience; second, the reasons why these precursors did not evolve into a severe accident. Third, whether lessons learned from these precursor events were adequately considered by member countries; and finally, if the operating experience feedback system needs to be improved, based on the previous analysis. To address the second question which is much more challenging, the report considered precursor events identified through a search and analysis of the IRS database and also precursors events based on risk significance. Both methods can point out areas where further work may be needed, even if it depends heavily on design and site-specific factors. From the operating experience side, more efforts are needed to ensure timely and full implementation of lessons learnt from precursor events. Concerning risk considerations, a combined use of risk precursors and operating experience may drive to effective changes to plants to reduce risk. The report also contains a short description and evaluation of selected precursors that are related to the course of the Fukushima Daiichi NPP accident. The report addresses the question whether operating experience feedback can be effectively used to identify plant vulnerabilities and minimize potential for severe core damage accidents. Based on several of the precursor events national or international in-depth evaluations were started. The vulnerability of NPPs due to external and internal flooding has clearly been addressed. In addition to the IRS based investigation, the WGRISK was asked to identify important precursor events based on risk significance. These precursors have

  19. 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)

  20. An ultrasensitive and highly selective fluorescent and colorimetric chemosensor for citrate ions based on rhodamine B and its application as the first molecular security keypad lock based on phosphomolybdic acid and citrate inputs

    Energy Technology Data Exchange (ETDEWEB)

    Tavallali, Hossein, E-mail: Tavallali@pnu.ac.ir; Baezzat, Mohammad-Reza; Deilamy-Rad, Gohar; Parhami, Abolfath; Hasanli, Nahid

    2015-04-15

    Rhodamine B (Rh{sub B}) has been developed as novel and efficient colorimetric and fluorometric chemosensor for citrate ions (Cit{sup 3−}) in an absolutely aqueous media. The UV–vis absorption and fluorescent emission titrations experiments have been employed to study the sensing process. Rh{sub B} could act as an efficient “ON–OFF” fluorescent chemosensor for phosphomolybdic acid (PMA) based on an electron transfer (ET) process. Also (Rh{sub B}{sup +}){sub 3}.PMA{sup 3−} could operate as an “OFF–ON” fluorescent chemosensor for citrate ions based on a ligand substitution process. The chemosensor Rh{sub B} shows excellent fluorescence sensitivity and selectivity toward citrate in aqueous media, and displays ON–OFF–ON type fluorescence change with alternately adding PMA and citrate to the media along with reversible association–dissociation of the complex. The (Rh{sub B}{sup +}){sub 3}.PMA{sup 3−} can be applied to the quantification of citrate with a linear ranges covering from 0.053 to 0.83 and 0.08 to 1.6 µM by detection limits of 6.0 and 9.1 nM for fluorescence and colorimetric methods respectively. The keypad lock operation is particularly important, as the output of the system depends not only on the proper combination but also on the order of input signals, creating the correct password that can be used to “open” this molecular keypad lock through strong fluorescence emission at 575 nm. As a whole, its various logic gate properties may improve its impact for the development of new-generation “intelligence” digital devices. The ionic PMA and Cit{sup 3−} inputs to (Rh{sub B}{sup +}){sub 3}.PMA{sup 3−} have been mimicked as a superimposed electronic molecular keypad lock. Also indicates that Rh{sub B} is suitable for the detection of Cit{sup 3−} ions in the biological environment. - Highlights: • Our probe is commercially available with good photostability and high quantum yield. • Both color and fluorescence change

  1. Enumeration of minimal stoichiometric precursor sets in metabolic networks.

    Science.gov (United States)

    Andrade, Ricardo; Wannagat, Martin; Klein, Cecilia C; Acuña, Vicente; Marchetti-Spaccamela, Alberto; Milreu, Paulo V; Stougie, Leen; Sagot, Marie-France

    2016-01-01

    What an organism needs at least from its environment to produce a set of metabolites, e.g. target(s) of interest and/or biomass, has been called a minimal precursor set. Early approaches to enumerate all minimal precursor sets took into account only the topology of the metabolic network (topological precursor sets). Due to cycles and the stoichiometric values of the reactions, it is often not possible to produce the target(s) from a topological precursor set in the sense that there is no feasible flux. Although considering the stoichiometry makes the problem harder, it enables to obtain biologically reasonable precursor sets that we call stoichiometric. Recently a method to enumerate all minimal stoichiometric precursor sets was proposed in the literature. The relationship between topological and stoichiometric precursor sets had however not yet been studied. Such relationship between topological and stoichiometric precursor sets is highlighted. We also present two algorithms that enumerate all minimal stoichiometric precursor sets. The first one is of theoretical interest only and is based on the above mentioned relationship. The second approach solves a series of mixed integer linear programming problems. We compared the computed minimal precursor sets to experimentally obtained growth media of several Escherichia coli strains using genome-scale metabolic networks. The results show that the second approach efficiently enumerates minimal precursor sets taking stoichiometry into account, and allows for broad in silico studies of strains or species interactions that may help to understand e.g. pathotype and niche-specific metabolic capabilities. sasita is written in Java, uses cplex as LP solver and can be downloaded together with all networks and input files used in this paper at http://www.sasita.gforge.inria.fr.

  2. 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.

  3. 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.

  4. 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

  5. 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)

  6. 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

  7. 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

  8. 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)

  9. An efficient and ultrasensitive rhodamine B-based reversible colorimetric chemosensor for naked-eye recognition of molybdenum and citrate ions in aqueous solution: sensing behavior and logic operation.

    Science.gov (United States)

    Tavallali, Hossein; Deilamy-Rad, Gohar; Parhami, Abolfath; Hasanli, Nahid

    2015-03-15

    In this paper we manifest a novel rhodamine B (RhB) based colorimetric chemosensor for molybdenum and citrate ions (Cit(3-)) in an absolutely aqueous media. It has been identified as highly sensitive probe for Mo(6+) which responds at 4.0 nmol L(-1) concentration levels. RhB while combined with Mo(6+) in aqueous solution displays a color changing from pink to purple which could be quickly dissociated by the addition of citrate in this system so that reversible color changes from purple to pink can be achieved. The comparison of this method with some other methods for citrate indicates that this is the only method which can detect citrate in aqueous solution by color changes. This chemosensor can be applied for quantification of citrate with a linear range covering from 1.67×10(-7) to 1.22×10(-5) M and a detection limit of 2.0×10(-8) M. Moreover, the response of the chemosensor toward Mo(6+) and citrate is fast. In addition, based on above sensing mechanism, an IMPLICATION logic operation can be achieved using Mo(6+) ion and Cit(3-) as the inputs, making RhB a promising candidate for further applications in molecular logic devices and also indicates that RhB is suitable for the detection of Mo(6+) and Cit(3-) ions in real samples. Copyright © 2014 Elsevier B.V. All rights reserved.

  10. Advanced glycation end products, physico-chemical and sensory characteristics of cooked lamb loins affected by cooking method and addition of flavour precursors

    DEFF Research Database (Denmark)

    Roldan, Mar; Loebner, Jürgen; Degen, Julia

    2015-01-01

    The influence of the addition of a flavour enhancer solution (FES) (d-glucose, d-ribose, l-cysteine and thiamin) and of sous-vide cooking or roasting on moisture, cooking loss, instrumental colour, sensory characteristics and formation of Maillard reaction (MR) compounds in lamb loins was studied....... FES reduced cooking loss and increased water content in sous-vide samples. FES and cooking method showed a marked effect on browning development, both on the meat surface and within. FES led to tougher and chewier texture in sous-vide cooked lamb, and enhanced flavour scores of sous-vide samples more...

  11. Advanced glycation end products, physico-chemical and sensory characteristics of cooked lamb loins affected by cooking method and addition of flavour precursors.

    Science.gov (United States)

    Roldan, Mar; Loebner, Jürgen; Degen, Julia; Henle, Thomas; Antequera, Teresa; Ruiz-Carrascal, Jorge

    2015-02-01

    The influence of the addition of a flavour enhancer solution (FES) (d-glucose, d-ribose, l-cysteine and thiamin) and of sous-vide cooking or roasting on moisture, cooking loss, instrumental colour, sensory characteristics and formation of Maillard reaction (MR) compounds in lamb loins was studied. FES reduced cooking loss and increased water content in sous-vide samples. FES and cooking method showed a marked effect on browning development, both on the meat surface and within. FES led to tougher and chewier texture in sous-vide cooked lamb, and enhanced flavour scores of sous-vide samples more markedly than in roasted ones. FES added meat showed higher contents of furosine; 1,2-dicarbonyl compounds and 5-hydroxymethylfurfural did not reach detectable levels. N-ε-carboxymethyllysine amounts were rather low and not influenced by the studied factors. Cooked meat seems to be a minor dietary source of MR products, regardless the presence of reducing sugars and the cooking method. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. 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.

  13. Preparation of superconductor precursor powders

    Science.gov (United States)

    Bhattacharya, Raghunath

    1998-01-01

    A process for the preparation of a precursor metallic powder composition for use in the subsequent formation of a superconductor. The process comprises the steps of providing an electrodeposition bath comprising an electrolyte medium and a cathode substrate electrode, and providing to the bath one or more soluble salts of one or more respective metals which are capable of exhibiting superconductor properties upon subsequent appropriate treatment. The bath is continually energized to cause the metallic and/or reduced particles formed at the electrode to drop as a powder from the electrode into the bath, and this powder, which is a precursor powder for superconductor production, is recovered from the bath for subsequent treatment. The process permits direct inclusion of all metals in the preparation of the precursor powder, and yields an amorphous product mixed on an atomic scale to thereby impart inherent high reactivity. Superconductors which can be formed from the precursor powder include pellet and powder-in-tube products.

  14. Toward a theory of precursors

    International Nuclear Information System (INIS)

    Freivogel, Ben; Giddings, Steven B.; Lippert, Matthew

    2002-01-01

    To better understand the possible breakdown of locality in quantum gravitational systems, we pursue the identity of precursors in the context of the anti-de Sitter/conformal field theory correspondence. Holography implies a breakdown of standard bulk locality which we expect to occur only at extremely high energy. We consider precursors that encode bulk information causally disconnected from the boundary and whose measurement involves nonlocal bulk processes. We construct a toy model of holography which encapsulates the expected properties of precursors and compare it with previous such discussions. If these precursors can be identified in the gauge theory, they are almost certainly Wilson loops, perhaps with decorations, but the relevant information is encoded in the high-energy sector of the theory and should not be observable by low energy measurements. This would be in accord with the locality bound, which serves as a criterion for situations where breakdown of bulk locality is expected

  15. Functional Nanoporous Polymers from Block Copolymer Precursors

    DEFF Research Database (Denmark)

    Guo, Fengxiao

    Abstract Self-assembly of block copolymers provides well-defined morphologies with characteristic length scales in the nanometer range. Nanoporous polymers prepared by selective removal of one block from self-assembled block copolymers offer great technological promise due to their many potential...... functionalities remains a great challenge due to the limitation of available polymer synthesis and the nanoscale confinement of the porous cavities. The main topic of this thesis is to develop methods for fabrication of functional nanoporous polymers from block copolymer precursors. A method has been developed......, where living anionic polymerization and atom transfer radical polymerization (ATRP) are combined to synthesize a polydimethylsiloxane-b-poly(tert-butyl acrylate)-b-polystyrene (PDMS-b-PtBA-b-PS) triblock copolymer precursor. By using either anhydrous hydrogen fluoride or trifluoroacetic acid, PtBA block...

  16. SHORT COMMUNICATION SYNTHESIS OF TRIBUTYL CITRATE ...

    African Journals Online (AJOL)

    Preferred Customer

    hysteresis loop exhibits at high relative pressure corresponding to capillary condensation. From. BET method and BJH analysis, the mesoporous molecular sieve MCM-41 possesses a uniformly sized mesoporous with diameters 2.8 nm, larger surface area of more than 573 m2/g. Characterization of TBC. The structure of ...

  17. PRECURSORS OF EARTHQUAKES: VLF SIGNALSIONOSPHERE IONOSPHERE RELATION

    Directory of Open Access Journals (Sweden)

    Mustafa ULAS

    2013-01-01

    Full Text Available lot of people have died because of earthquakes every year. Therefore It is crucial to predict the time of the earthquakes reasonable time before it had happed. This paper presents recent information published in the literature about precursors of earthquakes. The relationships between earthquakes and ionosphere are targeted to guide new researches in order to study further to find novel prediction methods.

  18. Precursor systems analyses of automated highway systems. Knowledge based systems and learning methods for AHS. Volume 10. Final report, September 1993-February 1995

    Energy Technology Data Exchange (ETDEWEB)

    Schmoltz, J.; Blumer, A.; Noonan, J.; Shedd, D.; Twarog, J.

    1995-06-01

    Managing each AHS vehicle and the AHS system as a whole is an extremely complex yndertaking. The authors have investigated and now report on Artificial Intelligence (AI) approaches that can help. In particular, we focus on AI technologies known as Knowledge Based Systems (KBSs) and Learning Methods (LMs). Our primary purpose is to identify opportunities: we identify several problems in AHS and AI technologies that can solve them. Our secondary purpose is to examine in some detail a subset of these opportunities: we examine how KBSs and LMs can help in controlling the high level movements--e.g., keep in lane, change lanes, speed up, slow down--of an automated vehicle. This detailed examination includes the implementation of a prototype system having three primary components. The Tufts Automated Highway System Kit(TAHSK) discrete time micro-level traffic simulator is a generic AHS simulator. TAHSK interfaces with the Knowledge Based Controller (KBCon) knowledge based high level controller, which controls the high level actions of individual AHS vehicles. Finally, TAHSK also interfaces with a Reinforcement learning (RL) module that was used to explore the possibilities of RL techniques in an AHS environment.

  19. Synthesis of Alkanethiolate-Capped Metal Nanoparticles Using Alkyl Thiosulfate Ligand Precursors: A Method to Generate Promising Reagents for Selective Catalysis

    Directory of Open Access Journals (Sweden)

    Khin Aye San

    2018-05-01

    Full Text Available Evaluation of metal nanoparticle catalysts functionalized with well-defined thiolate ligands can be potentially important because such systems can provide a spatial control in the reactivity and selectivity of catalysts. A synthetic method utilizing Bunte salts (sodium S-alkylthiosulfates allows the formation of metal nanoparticles (Au, Ag, Pd, Pt, and Ir capped with alkanethiolate ligands. The catalysis studies on Pd nanoparticles show a strong correlation between the surface ligand structure/composition and the catalytic activity and selectivity for the hydrogenation/isomerization of alkenes, dienes, trienes, and allylic alcohols. The high selectivity of Pd nanoparticles is driven by the controlled electronic properties of the Pd surface limiting the formation of Pd–alkene adducts (or intermediates necessary for (additional hydrogenation. The synthesis of water soluble Pd nanoparticles using ω-carboxylate-S-alkanethiosulfate salts is successfully achieved and these Pd nanoparticles are examined for the hydrogenation of various unsaturated compounds in both homogeneous and heterogeneous environments. Alkanethiolate-capped Pt nanoparticles are also successfully synthesized and further investigated for the hydrogenation of various alkynes to understand their geometric and electronic surface properties. The high catalytic activity of activated terminal alkynes, but the significantly low activity of internal alkynes and unactivated terminal alkynes, are observed for Pt nanoparticles.

  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. Comparison of letrazole and Clomiphene Citrate in Women with Polycystic Ovaries Undergoing Ovarian Stimulation

    International Nuclear Information System (INIS)

    Sharief, M.; Nafee, N. R.

    2015-01-01

    Objective: To compare the efficacy of letrazole in the induction of ovulation with clomiphene citrate in patients with polycystic ovary syndrome and primary infertility. Methods: The prospective clinical trial was conducted at Basrah Maternity and Child Hospital, Basrah, Iraq, between January 2012 and April 2013, and comprised women with polycystic ovarian syndrome and primary infertility who were randomised into 2 groups. Group A received 100-200mg clomiphene citrate daily while group 2 received letrazole (2.5-5mg) daily. Both groups were followed by ultrasound until the dominant follicle reached a diameter >18mm, human chorionic gonadotropin10.000 U/L was given and timed intercourse was advised. Results: Of the 75 subjects in the study, 40(53.3 percent) were in group A and 35(46.6 percent) in group B. The mean age in group A was 25.3+2.1 years versus 26.1+1.3 years in group B (p=0.05). The number of mature follicles was significantly lower, but the endometrial thickness and ovulation were significantly higher in group B than in group A (p<0.05 each). There was no significant difference in pregnancy rate between the two groups (p>0.05). Conclusion: Letrazole may have a role as the first-line treatment for unovulatory patients with polycystic ovary syndrome. (author)

  2. Clomifene citrate or low-dose FSH for the first-line treatment of infertile women with anovulation associated with polycystic ovary syndrome: a prospective randomized multinational study

    NARCIS (Netherlands)

    Homburg, R.R.; Hendriks, M.L.; König, T.E.; Anderson, R.A.; Balen, A.H.; Brincat, M.; Child, T.; Davies, M.; D'Hooghe, T.; Martinez, A; Rajkhowa, M.; Rueda-Saenz, R.; Hompes, P.G.A.; Lambalk, C.B.

    2012-01-01

    BACKGROUND: Clomifene citrate (CC) is accepted as the first-line method for ovulation induction (OI) in patients with polycystic ovary syndrome (PCOS) associated with infertility owing to anovulation. Low-dose FSH has been reserved for women failing to conceive with CC. In this RCT, we tested the

  3. Synthesis of ZnS thin films from aqueous caustic of trisodium citrate and their properties

    Directory of Open Access Journals (Sweden)

    Martyn A. Sozanskyi

    2015-12-01

    Full Text Available Zinc sulfide (ZnS thin films due to their properties are widely used in various electronic optical devices. They are produced by several methods, among which – vacuum sublimation, high frequency sputtering method, quasiclosed volume method, sol-gel method, electrodeposition. These methods have high energy consumption which increases the price of ZnS thin films. Aim: The aim of this work is to establish the optimal parameters of the synthesis of ZnS thin films of the aqueous caustic and the correlation between content of zinc in the synthesized films determined by the method of stripping voltammetry and thickness, structural, morphological and optical parameters. Materials and Methods: The ZnS thin films were obtained from aqueous caustics of zinc-containing salt using chemical deposition. Fresh solution of zinc-containing salt, trisodium citrate (Na3C6H5O7 as a complexing agent, thiourea ((NH22CS and ammonium hydroxide (NH4OH was used for the synthesis of ZnS films by chemical deposition. The deposition was performed on prepared glass substrates with the area of 5,76 cm2. Results: The phase mixture of the films has been determined. It showed the presence of ZnS compounds in the cubic modification (sphalerite. Stripping voltammetry was used to determine the mass of zinc in the ZnS films on various conditions of synthesis, namely on the concentration of the initial zinc-containing salt, trisodium citrate, thiourea, deposition time and temperature. The surface morphology, optical properties, the thickness of the ZnS resulting films have been studied. Conclusions: The optimal conditions for the synthesis of ZnS films were found based on these data. Three-dimensional surface morphology of ZnS film studies showed its smoothness, uniformity, integrity and confirmed the correctness of determining the optimal synthesis parameters.

  4. 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.

  5. Gallium-67 citrate scan in extrapulmonary tuberculosis

    International Nuclear Information System (INIS)

    Lin Wanyu

    1999-01-01

    Aim: Whole-body gallium scan was performed to evaluate the usefulness of gallium scan for detecting extrapulmonary tuberculosis (TB) lesions. Methods: Thirty-seven patients with extrapulmonary TB were included in this study. Four patients were found to have two lesions. Totally, 41 lesions were identified, including 19 TB arthritis, 8 spinal TB, 5 TB meningitis, 3 TB lymphadenopathy, 2 TB pericarditis, 1 TB peritonitis, 1 intestinal TB, 1 skin TB and 1 renal TB. Results: Of the 41 extrapulmonary TB lesions, gallium scan detected 32 lesions with a sensitivity of 78%. All the patients with TB meningitis showed negative gallium scan. When the five cases of TB meningitis were excluded, the detection sensitivity of gallium scan increased to 88.9% (32/36). Conclusion: Our data revealed that gallium scan is a convenient and useful method for evaluating extrapulmonary TB lesions other than TB-meningitis. We suggest that gallium scan be included in the clinical routine for patients with suspected extrapulmonary TB. (orig.) [de

  6. Gallium-67 citrate scan in extrapulmonary tuberculosis

    Energy Technology Data Exchange (ETDEWEB)

    Lin Wanyu [Taichung Veterans General Hospital (Taiwan). Dept. of Nuclear Medicine; Hsieh Jihfang [Chi-Mei Foundation Hospital, Tainan (Taiwan)

    1999-07-01

    Aim: Whole-body gallium scan was performed to evaluate the usefulness of gallium scan for detecting extrapulmonary tuberculosis (TB) lesions. Methods: Thirty-seven patients with extrapulmonary TB were included in this study. Four patients were found to have two lesions. Totally, 41 lesions were identified, including 19 TB arthritis, 8 spinal TB, 5 TB meningitis, 3 TB lymphadenopathy, 2 TB pericarditis, 1 TB peritonitis, 1 intestinal TB, 1 skin TB and 1 renal TB. Results: Of the 41 extrapulmonary TB lesions, gallium scan detected 32 lesions with a sensitivity of 78%. All the patients with TB meningitis showed negative gallium scan. When the five cases of TB meningitis were excluded, the detection sensitivity of gallium scan increased to 88.9% (32/36). Conclusion: Our data revealed that gallium scan is a convenient and useful method for evaluating extrapulmonary TB lesions other than TB-meningitis. We suggest that gallium scan be included in the clinical routine for patients with suspected extrapulmonary TB. (orig.) [German] Ziel: Es wurden Ganzkoerper-Gallium-Szintigramme angefertigt, um den Nutzen der Gallium-Szintigraphie zur Erfassung von extrapulmonalen Tuberkuloseherden (TB) zu erfassen. Methoden: 37 Patienten mit extrapulmonaler TB wurden eingeschlossen. 4 Patienten hatten 2 Laesionen. Insgesamt wurden 41 Laesionen identifiziert, hierunter 19 TB-Arthritis, 8 spinale TB, 5 TB-Meningitis, 3 TB-Lymphadenopathie, 2 TB-Perikarditis, 1 TB-Peritonitis, 1 intestinale TB, 1 Haut-TB und eine Nieren-TB. Ergebnisse: Von den 41 extrapulmonalen TB-Herden erfasste die Gallium-Szintigraphie 32 Herde mit einer Sensitivitaet von 78%. Alle Patienten mit TB-Meningitis zeigten einen negativen Gallium-Scan. Wenn die 5 Faelle mit TB-Meningitis ausgeschlossen wurden, stieg die Sensitivititaet der Gallium-Szintigraphie auf 88,9% (32/36). Schlussfolgerung: Die Daten zeigen, dass die Gallium-Szintigraphie eine einfache und nuetzliche Methode zur Erfassung extrapulmonaler TB-Herde ist

  7. Metformin versus chromium picolinate in clomiphene citrate-resistant patients with PCOs: A double-blind randomized clinical trial

    Directory of Open Access Journals (Sweden)

    Sedigheh Amooee

    2013-01-01

    Full Text Available Background: Chromium picolinate could be effective in clomiphen citrate resistant PCOS patients. Objective: To compare the effects of chromium picolinate vs. metformin in clomiphen citrate resistant PCOS patients. Materials and Methods: The present randomized clinical trial was performed on 92 women with clomiphen citrate-resistant PCOS at the clinics which were affiliated to Shiraz University of Medical Sciences, Shiraz, Iran. The subjects were randomly assigned to two groups receiving either chromium picolinate (200μg daily or metformin (1500mg daily for 3 months. Anthropometric and hormonal profile were measured and compared both before and after the treatment. Ovulation and pregnancy rate was measured in the two study groups, as well. Results: Chromium picolinate significantly decreased fasting blood sugar (FBS after 3 months of treatment (p=0.042. In the same way, the serum levels of fasting insulin had significantly decreased leading to an increase in insulin sensitivity as measured by QUICKI index (p=0.014. In comparison to the patients who received chromium picolinate, those who received metformin had significantly lower levels of testosterone (p=0.001 and free testosterone (p=0.001 after 3 months of treatment. Nevertheless, no significant difference was found between the two study groups regarding ovulation (p=0.417 and pregnancy rates (p=0.500. Conclusion: Chromium picolinate decreased FBS and insulin levels and, thus, increased insulin sensitivity in clomiphene citrate-resistance PCOS women. These effects were comparable with metformin; however, metformin treatment was associated with decreased hyperandrogenism. Overall, chromium picolinate was better tolerated compared to metformin; nonetheless, the two study groups were not significantly different regarding ovulation and pregnancy rates.

  8. Stability of Fentanyl Citrate in Polyolefin Bags.

    Science.gov (United States)

    Donnelly, Ronald F

    2016-01-01

    Fentanyl is used to manage pain because it is a potent lipophilic opiate agonist. The stability of fentanyl in polyolefin bags when diluted to either 10 µg/mL or 50 µg/mL with sodium chloride 0.9% has not been studied. The chemical stability of fentanyl 50 µg/mL packaged in polyvinyl chloride bags has been studied, however, the stability in polyolefin bags is lacking. Polyolefin bags were aseptically filled with either 10-µg/mL or 50-µg/mL fentanyl solution. Containers were then stored at either 5°C and protected from light or 22°C and exposed to light for 93 days. Fentanyl peaks were monitored using a stability-indicatin high-performance liquid chromatographic method. Changes to color, clarity, and pH were also monitored. There were no signs of chemical degradation of fentanyl packaged in polyolefin bags at either 5°C or 22°C after storage for 93 days. Over the course of the study, all solutions remained colorless and clear. The pH showed a slight decrease during the 93 days of storage. The stability of both undiluted (50-µg/mL) and diluted (10-µg/mL) fentanyl solutions when packaged in polyolefin bags was 93 days when stored at either 5°C or 22°C. Copyright© by International Journal of Pharmaceutical Compounding, Inc.

  9. 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.

  10. 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.

  11. The significance of anthropometric and endocrine parameters in ovulation induction with clomiphene citrate in women with polycystic ovary syndrome.

    Science.gov (United States)

    Akpinar, Funda; Dilbaz, Berna; Cırık, Derya A; Yilmaz, Saynur; Kiykac, Sadiman; Karahanoglu, Ertugrul; Mollamahmutoglu, Leyla

    2016-11-01

    To investigate factors associated with the response to ovarian stimulation in patients with polycystic ovary syndrome. Methods: The records of patients with polycystic ovary syndrome and infertility who underwent ovulation induction with clomiphene citrate were reviwed between January 2011 and December 2014 in Etlik Zübeyde Hanim Women's Health Training and Research Hospital Ankara, Turkey. The anthropometric and endocrine factors of patients who were resistant to treatment at a dose of 150 mg/day (n=84) were compared with those who responded with growth of at least one graaffian follicle at a dose of 50 mg/day (n=342). Results: Of the parameters examined, body mass index, luteinizing hormone level, and luteinizing hormone/follicle stimulating hormone ratio were significantly higher in the clomiphene citrate-resistant group compared with the responsive group. Conclusion: Reproductive treatment in patients with polycystic ovary syndrome show different outcomes. Significantly higher body mass index, luteinizing hormone level, and luteinizing hormone/follicle stimulating hormone ratio observed in clomiphene citrate resistant group can be a possible explanation for this impedance.

  12. Effects of Sodium Citrate on the Ammonium Sulfate Recycled Leaching of Low-Grade Zinc Oxide Ores

    Science.gov (United States)

    Yang, Kun; Li, Shi-wei; Zhang, Li-bo; Peng, Jin-hui; Ma, Ai-yuan; Wang, Bao-bao

    2016-03-01

    The effects of sodium citrate on ammonium sulfate recycled leaching of low-grade zinc oxide ores were studied. By applying various kinds of detection and analysis techniques such as chemical composition analysis, chemical phase method, scanning electron microscopy and energy dispersive spectrum (SEM/EDS), X-ray diffraction (XRD) and Fourier-transforming infrared spectrum (FT-IR), zinc raw ore, its leaching slag and the functional mechanism of sodium citrate were investigated. Based on a comprehensive analysis, it can be concluded that in contrast to hemimorphite (Zn4Si2O7(OH)2 · H2O), amorphous smithsonite (ZnCO3) and zinc silicate (Zn2SiO4) prove to be refractory phases under ammonium sulfate leaching, while sodium citrate has a better chelating action with the refractory phases, resulting in a higher zinc leaching rate. Under conditions of [NH3]/[NH3]T molar ratio being 0.5, [NH3]T being 7.5 mol/L, [Na3C6H5O7] being 0.2 mol/L, S/L ratio being 1:5, temperature being 303 K, holding time being 1 h in each of the two stages, and stirring rate being 300 rpm, the leaching rate of zinc reached 93.4%. In this article, sulfate ammonium recycled technology also reveals its unique advantage in processing low-grade zinc oxide ores accompanied by high silicon and high alkaline gangue.

  13. Citrate content of bone for time since death estimation: results from burials with different physical characteristics and known PMI.

    Science.gov (United States)

    Kanz, Fabian; Reiter, Christian; Risser, Daniele U

    2014-05-01

    A recently introduced method to determine the postmortem interval (PMI) based on quantification of the citrate content in bone was applied on the temporal bones and femora of 20 individuals buried in wooden coffins (WO) and body bags (BB), respectively. Concerning known vs. calculated PMI, a significant difference between the temporal and the femur bone samples of the same individuals was observed in the BB group (p = 0.012). In contrast, differences were insignificant for the WO group (p = 0.400). Moreover, similar levels of underestimation of PMIs resulted from the analysis of the femora for both burial groups (p = 0.247). Also, there was consistently less citrate preserved in the flat temporal bones as compared to the femora, indicating that the cortical layer of the long bones should be preferentially employed for citrate-based PMI estimations. The results call for additional research on subsurface-buried and surface-deposited remains to enhance the accuracy of the published PMI equation. © 2014 American Academy of Forensic Sciences.

  14. 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

  15. 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.

  16. Preparation of YBa2Cu3O7-x superconducting solutions and films from alkoxide-based precursors using sol-gel method and investigation of their chemical reaction mechanisms

    International Nuclear Information System (INIS)

    Mutlu, Ibrahim Halil; Acun, Hediye; Celik, Erdal; Turkmen, Hasan

    2007-01-01

    In the development of coated superconductors sol-gel technique has been widely used as an effective processing method, especially in making long-length wires and tapes. However, one drawback associated with the deposition of YBa 2 Cu 3 O 7-x and Gd 2 O 3 buffer layer on Ni tape is the adhesion characteristic at interfaces YBCO-Gd 2 O 3 and Gd 2 O 3 -NiO and NiO-Ni substrate. In this paper, two strategies for adhesion enhancement of multilayered ceramic oxide coatings on Ni substrate were proposed: (1) formation of chemical bonds through surface condensation reactions, and development of ceramic networks through diffusion of alkoxide precursors. The current research has focused on the fabrication and adhesion of YBCO coatings on buffered Ni substrate using nine solutions prepared from Y, Ba and Cu alkoxides, solvent and chelating agent. Only two of YBCO solutions were successfully obtained while the rest of them were unsuccessful. Among these solutions we scrutinized chemical reaction mechanisms of a successful and an unsuccessful solution for comparison. How the chemical bonds and solubility were affected by the acids, base and solvents used in the solutions was demonstrated. It was shown that pH of the solution, homogeneity of the solution and gelation, steric affect of the chemicals in sol-gel solutions are significant issues to obtain high quality superconducting YBCO thin films. In addition, X-ray diffraction (XRD) was used to analyze phase structure of YBCO and compare results of chemical reactions obtained by a chemdraw programme. Scanning electron microscope (SEM) studies was carried out to examine microstructures of YBCO films produced from alkoxide precursors, solvent, chelating agent and modifying liquid chemical materials such as triethanolamine or ammonium hydroxide. It was found to be YBCO, Gd 2 O 3 , NiO and Ni phases in YBCO/Gd 2 O 3 /Ni sample from XRD analysis. That the solution prepared by using triethanolamine provided the best film quality and

  17. Synthesis and Characterization of TiO2(B Nanotubes Prepared by Hydrothermal Method Using [Ti8O12(H2O24]Cl8.HCl.7H2O as Precursor

    Directory of Open Access Journals (Sweden)

    Hari Sutrisno

    2010-04-01

    Full Text Available Low-dimension TiO2-related material has been synthesized by hydrothermal treatment of [Ti8O12(H2O24]Cl8.HCl.7H2O crystal as precursor in a 10 M NaOh aqueous solution at 150 C for 24 h. Characterization of the obtained product was carried out by a range of techniques including X-ray diffraction (XRD, high resolution scanning electron microscopy (HRSEM, high resolution transmission electron microscopy (HRTEM, Raman spectroscopy and nitrogen adsorption-desorption isotherm (Brunauer-Emmett-Teller (BET-Barret-Joyner-Halender (BJH. From HRTEM, XRD and Raman spectra showed that the obtained product has a TiO2(B structure. According to HRTEM observations, it was found that TiO2(B has nanotubular structure with approximately 5-8 nm in outer and 3-6 nm in inner diameter. The BET surface area of TiO2(B nanotubes is quiet large, values of 418.3163 m2/g being obtained. Pore structure analyisis by the BJH method showed that the average pore diameter of TiO2(B nanotubes has 5.5781 nm.

  18. 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.

  19. 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.

  20. CHEMICAL VAPOUR DEPOSITION FROM A RADIATION-SENSITIVE PRECURSOR

    DEFF Research Database (Denmark)

    2017-01-01

    The present invention relates in one aspect to a method of depositing a thin film on a substrate by chemical vapour deposition (CVD) from a radiation-sensitive precursor substance. The method comprises the steps of: (i) placing the substrate in a reaction chamber of a CVD system; (ii) heating...... heating pulse followed by an idle period; (iii) during at least one of the idle periods, providing a pressure pulse of precursor substance inside the reaction chamber by feeding at least one precursor substance to the reaction chamber so as to establish a reaction partial pressure for thin film deposition...... is formed. According to a further aspect, the invention relates to a chemical vapour deposition (CVD) system for depositing a thin film onto a substrate using precursor substances containing at least one radiation sensitive species....

  1. 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.

  2. 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.

  3. 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.

  4. 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

  5. Precursor Mediated Synthesis of Nanostructured Silicas: From Precursor-Surfactant Ion Pairs to Structured Materials.

    Science.gov (United States)

    Hesemann, Peter; Nguyen, Thy Phung; Hankari, Samir El

    2014-04-11

    The synthesis of nanostructured anionic-surfactant-templated mesoporous silica (AMS) recently appeared as a new strategy for the formation of nanostructured silica based materials. This method is based on the use of anionic surfactants together with a co-structure-directing agent (CSDA), mostly a silylated ammonium precursor. The presence of this CSDA is necessary in order to create ionic interactions between template and silica forming phases and to ensure sufficient affinity between the two phases. This synthetic strategy was for the first time applied in view of the synthesis of surface functionalized silica bearing ammonium groups and was then extended on the formation of materials functionalized with anionic carboxylate and bifunctional amine-carboxylate groups. In the field of silica hybrid materials, the "anionic templating" strategy has recently been applied for the synthesis of silica hybrid materials from cationic precursors. Starting from di- or oligosilylated imidazolium and ammonium precursors, only template directed hydrolysis-polycondensation reactions involving complementary anionic surfactants allowed accessing structured ionosilica hybrid materials. The mechanistic particularity of this approach resides in the formation of precursor-surfactant ion pairs in the hydrolysis-polycondensation mixture. This review gives a systematic overview over the various types of materials accessed from this cooperative ionic templating approach and highlights the high potential of this original strategy for the formation of nanostructured silica based materials which appears as a complementary strategy to conventional soft templating approaches.

  6. Precursor Mediated Synthesis of Nanostructured Silicas: From Precursor-Surfactant Ion Pairs to Structured Materials

    Directory of Open Access Journals (Sweden)

    Peter Hesemann

    2014-04-01

    Full Text Available The synthesis of nanostructured anionic-surfactant-templated mesoporous silica (AMS recently appeared as a new strategy for the formation of nanostructured silica based materials. This method is based on the use of anionic surfactants together with a co-structure-directing agent (CSDA, mostly a silylated ammonium precursor. The presence of this CSDA is necessary in order to create ionic interactions between template and silica forming phases and to ensure sufficient affinity between the two phases. This synthetic strategy was for the first time applied in view of the synthesis of surface functionalized silica bearing ammonium groups and was then extended on the formation of materials functionalized with anionic carboxylate and bifunctional amine-carboxylate groups. In the field of silica hybrid materials, the “anionic templating” strategy has recently been applied for the synthesis of silica hybrid materials from cationic precursors. Starting from di- or oligosilylated imidazolium and ammonium precursors, only template directed hydrolysis-polycondensation reactions involving complementary anionic surfactants allowed accessing structured ionosilica hybrid materials. The mechanistic particularity of this approach resides in the formation of precursor-surfactant ion pairs in the hydrolysis-polycondensation mixture. This review gives a systematic overview over the various types of materials accessed from this cooperative ionic templating approach and highlights the high potential of this original strategy for the formation of nanostructured silica based materials which appears as a complementary strategy to conventional soft templating approaches.

  7. Trending analysis of precursor events

    International Nuclear Information System (INIS)

    Watanabe, Norio

    1998-01-01

    The Accident Sequence Precursor (ASP) Program of United States Nuclear Regulatory Commission (U.S.NRC) identifies and categorizes operational events at nuclear power plants in terms of the potential for core damage. The ASP analysis has been performed on yearly basis and the results have been published in the annual reports. This paper describes the trends in initiating events and dominant sequences for 459 precursors identified in the ASP Program during the 1969-94 period and also discusses a comparison with dominant sequences predicted in the past Probabilistic Risk Assessment (PRA) studies. These trends were examined for three time periods, 1969-81, 1984-87 and 1988-94. Although the different models had been used in the ASP analyses for these three periods, the distribution of precursors by dominant sequences show similar trends to each other. For example, the sequences involving loss of both main and auxiliary feedwater were identified in many PWR events and those involving loss of both high and low coolant injection were found in many BWR events. Also, it was found that these dominant sequences were comparable to those determined to be dominant in the predictions by the past PRAs. As well, a list of the 459 precursors identified are provided in Appendix, indicating initiating event types, unavailable systems, dominant sequences, conditional core damage probabilities, and so on. (author)

  8. Synthesis of labelled ecdysone precursors

    International Nuclear Information System (INIS)

    Haag, T.; Hetru, C.; Nakatani, Y.; Luu, B.; Meister, M.; Pichat, L.; Audinot, M.

    1985-01-01

    High specific activity tritiated 3β,14α-dihydroxy-5β-cholest-7-en-6-one, has been prepared using a precursor which permits rapid and easy labelling. This compound is converted to ecdysone under in vitro conditions by insect prothoracic glands, a well known site of ecdysone biosynthesis. (author)

  9. 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.

  10. 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

  11. 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...

  12. 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...

  13. 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...

  14. 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.

  15. 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.

  16. Speciation of An(IV) (Pu, Np, U and Th) in citrate media

    Energy Technology Data Exchange (ETDEWEB)

    Bonin, L.; Moisy, P. [CEA Valrho, DEN/DRCP/SCPS/LCA, Bagnols sur Ceze (France); Cote, G. [Ecole Nationale Superieure de Chimie, 75 - Paris (France)

    2008-07-01

    The acquisition of additional data concerning actinide decorporation is planned under the French nuclear and environmental toxicology program. Citric acid is a fundamental biological constituent found at relatively high concentrations in blood plasma and is involved in many biological processes. Spectrophotometry was the primary method used to determine the speciation of An(IV)-citrate systems (Th, U, Np, Pu). Complexation phenomena were identified, especially the formation of complexes with 1:1 and 1:2 stoichiometries. The corresponding conditional constants were calculated according to the experimental conditions. Depending on the acid-base form of the ligand (H{sub 2}Cit{sup -}, HCit{sup 2-} or Cit{sup 3-}) the apparent stability constants were also calculated and compared for various tetravalent actinides. (orig.)

  17. The effects of creatine pyruvate and creatine citrate on performance during high intensity exercise

    Directory of Open Access Journals (Sweden)

    Purpura Martin

    2008-02-01

    Full Text Available Abstract Background A double-blind, placebo-controlled, randomized study was performed to evaluate the effect of oral creatine pyruvate (Cr-Pyr and creatine citrate (Cr-Cit supplementation on exercise performance in healthy young athletes. Methods Performance during intermittent handgrip exercise of maximal intensity was evaluated before (pretest and after (posttest 28 days of Cr-Pyr (5 g/d, n = 16, Cr-Cit (5 g/d, n = 16 or placebo (pla, 5 g/d, n = 17 intake. Subjects performed ten 15-sec exercise intervals, each followed by 45 sec rest periods. Results Cr-Pyr (p Conclusion It is concluded that four weeks of Cr-Pyr and Cr-Cit intake significantly improves performance during intermittent handgrip exercise of maximal intensity and that Cr-Pyr might benefit endurance, due to enhanced activity of the aerobic metabolism.

  18. The barley MATE gene, HvAACT1, increases citrate efflux and Al3+ tolerance when expressed in wheat and barley

    Science.gov (United States)

    Zhou, Gaofeng; Delhaize, Emmanuel; Zhou, Meixue; Ryan, Peter R.

    2013-01-01

    Background and Aims Aluminium is toxic in acid soils because the soluble Al3+ inhibits root growth. A mechanism of Al3+ tolerance discovered in many plant species involves the release of organic anions from root apices. The Al3+-activated release of citrate from the root apices of Al3+-tolerant genotypes of barley is controlled by a MATE gene named HvAACT1 that encodes a citrate transport protein located on the plasma membrane. The aim of this study was to investigate whether expressing HvAACT1 with a constitutive promoter in barley and wheat can increase citrate efflux and Al3+ tolerance of these important cereal species. Methods HvAACT1 was over-expressed in wheat (Triticum aestivum) and barley (Hordeum vulgare) using the maize ubiquitin promoter. Root apices of transgenic and control lines were analysed for HvAACT1 expression and organic acid efflux. The Al3+ tolerance of transgenic and control lines was assessed in both hydroponic solution and acid soil. Key Results and Conclusions Increased HvAACT1 expression in both cereal species was associated with increased citrate efflux from root apices and enhanced Al3+ tolerance, thus demonstrating that biotechnology can complement traditional breeding practices to increase the Al3+ tolerance of important crop plants. PMID:23798600

  19. [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.

  20. The proliferative human monocyte subpopulation contains osteoclast precursors

    Science.gov (United States)

    Lari, Roya; Kitchener, Peter D; Hamilton, John A

    2009-01-01

    Introduction Immediate precursors of bone-resorbing osteoclasts are cells of the monocyte/macrophage lineage. Particularly during clinical conditions showing bone loss, it would appear that osteoclast precursors are mobilized from bone marrow into the circulation prior to entering tissues undergoing such loss. The observed heterogeneity of peripheral blood monocytes has led to the notion that different monocyte subpopulations may have special or restricted functions, including as osteoclast precursors. Methods Human peripheral blood monocytes were sorted based upon their degree of proliferation and cultured in macrophage colony-stimulating factor (M-CSF or CSF-1) and receptor activator of nuclear factor-kappa-B ligand (RANKL). Results The monocyte subpopulation that is capable of proliferation gave rise to significantly more multinucleated, bone-resorbing osteoclasts than the bulk of the monocytes. Conclusions Human peripheral blood osteoclast precursors reside in the proliferative monocyte subpopulation. PMID:19222861

  1. 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

  2. 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

  3. 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...

  4. 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.

  5. The Innate Lymphoid Cell Precursor.

    Science.gov (United States)

    Ishizuka, Isabel E; Constantinides, Michael G; Gudjonson, Herman; Bendelac, Albert

    2016-05-20

    The discovery of tissue-resident innate lymphoid cell populations effecting different forms of type 1, 2, and 3 immunity; tissue repair; and immune regulation has transformed our understanding of mucosal immunity and allergy. The emerging complexity of these populations along with compounding issues of redundancy and plasticity raise intriguing questions about their precise lineage relationship. Here we review advances in mapping the emergence of these lineages from early lymphoid precursors. We discuss the identification of a common innate lymphoid cell precursor characterized by transient expression of the transcription factor PLZF, and the lineage relationships of innate lymphoid cells with conventional natural killer cells and lymphoid tissue inducer cells. We also review the rapidly growing understanding of the network of transcription factors that direct the development of these lineages.

  6. Precursor polymer compositions comprising polybenzimidazole

    Science.gov (United States)

    Klaehn, John R.; Peterson, Eric S.; Orme, Christopher J.

    2015-07-14

    Stable, high performance polymer compositions including polybenzimidazole (PBI) and a melamine-formaldehyde polymer, such as methylated, poly(melamine-co-formaldehyde), for forming structures such as films, fibers and bulky structures. The polymer compositions may be formed by combining polybenzimidazole with the melamine-formaldehyde polymer to form a precursor. The polybenzimidazole may be reacted and/or intertwined with the melamine-formaldehyde polymer to form the polymer composition. For example, a stable, free-standing film having a thickness of, for example, between about 5 .mu.m and about 30 .mu.m may be formed from the polymer composition. Such films may be used as gas separation membranes and may be submerged into water for extended periods without crazing and cracking. The polymer composition may also be used as a coating on substrates, such as metal and ceramics, or may be used for spinning fibers. Precursors for forming such polymer compositions are also disclosed.

  7. Clomiphene citrate versus high doses of gonadotropins for in vitro fertilisation in women with compromised ovarian reserve: a randomised controlled non-inferiority trial

    Directory of Open Access Journals (Sweden)

    Ragni Guido

    2012-12-01

    Full Text Available Abstract Background The aim of the present randomised controlled non-inferiority trial is to test whether in women with compromised ovarian reserve requiring in vitro fertilisation, a protocol of ovarian stimulation using exclusively clomiphene citrate performs similarly to a regimen with high doses of gonadotropins. Methods Women with day 3 serum FSH > 12 IU/ml on at least two occasions or previous poor response to hyper-stimulation were recruited at four Italian infertility units. Selected women were allocated to clomiphene citrate 150 mg/day from day 3 to day 7 of the cycle (n=145 or to a short protocol with GnRH agonist 0.1 mg and recombinant FSH 450 IU daily (n=146. They were randomised by means of a computer-generated list into two groups. The study was not blinded. The main outcome of the study was the delivery rate per started cycle. Results The study was interrupted after the scheduled two years of recruitment before reaching the sample size. 148 women were allocated to clomiphene citrate and 156 to the short protocol with high doses of gonadotropins; 124 and 125 participants were analysed in the groups, respectively. Women allocated to high doses of gonadotropins retrieved more oocytes and had a higher probability to perform embryo-transfer. However, the chances of success were similar. The delivery rate per started cycle in women receiving clomiphene citrate and high-dose gonadotropins was 3% (n=5 and 5% (n=7, respectively (p=0.77. The mean estimated cost per delivery in the two groups was 81,294 and 113,107 Euros, respectively. No side-effects or adverse events were observed. Conclusions In women with compromised ovarian reserve selected for in vitro fertilisation, ovarian stimulation with clomiphene citrate or high-dose gonadotropins led to similar chances of pregnancy but the former is less expensive. Trial registration Trial registered on http://www.clinicaltrials.gov (NCT01389713

  8. Comparison of pre-filter and post-filter ionised calcium monitoring in continuous veno-venous hemodiafiltration (CVVHD-F with citrate anti-coagulation.

    Directory of Open Access Journals (Sweden)

    Matthew J Brain

    Full Text Available It is widespread practice during citrate anticoagulated renal replacement therapy to monitor circuit ionised calcium (iCa2+ to evaluate the effectiveness of anticoagulation. Whether the optimal site to sample the blood path is before or after the haemofilter is a common question.Using a prospectively collected observational dataset from intensive care patients receiving pre-dilution continuous veno-venous haemodiafiltration (CVVHD-F with integrated citrate anticoagulation we compared paired samples of pre and post filter iCa2+ where the target range was 0.3-0.5 mmol.L-1 as well as concurrently collected arterial iCa2+. Two nested mixed methods linear models were fitted to the data describing post vs pre filter iCa2+, and the relationship of pre, post and arterial samples.An 11 bed general intensive care unit.450 grouped samples from 152 time periods in seven patients on CRRT with citrate anticoagulation.The relationship of post to pre-filter iCa2+ was not 1:1 with post = 0.082 + 0.751 x pre-filter iCa2+ (95% CI intercept: 0.015-0.152, slope 0.558-0.942. Variation was greatest between patients rather than between circuits within the same patient or citrate dose. Compared to arterial iCa2+ there was no significant difference between pre and post-filter sampling sites (F-value 0.047, p = 0.827.These results demonstrate that there is minimal difference between pre and post filter samples for iCa2+ monitoring of circuit anticoagulation in citrate patients relative to the arterial iCa2+ in CVVHD-F however compared to pre-filter sampling, post filter sampling has a flatter response and greater variation.

  9. Comparison of the therapeutic effects of sildenafil citrate, heparin and neuropeptides in a rat model of acetic acid-induced gastric ulcer.

    Science.gov (United States)

    Kalayci, Mehmet; Kocdor, Mehmet Ali; Kuloglu, Tuncay; Sahin, İbrahim; Sarac, Mehmet; Aksoy, Aziz; Yardim, Meltem; Dalkilic, Semih; Gursu, Onur; Aydin, Suna; Akkoc, Ramazan Fazil; Ugras, Meltem; Artas, Gokhan; Ozercan, İbrahim Hanifi; Ugur, Kader; Aydin, Suleyman

    2017-10-01

    The purpose of our investigative work has been to determine whether there can be therapeutic roles in the administration of sildenafil citrate, heparin and several neuropeptides on an animal model where gastric ulcers were induced with acetic acid, and to compare their efficacy. The animals were divided into 13 groups, with 4 animals in each. Gastric ulcers was induced in the animals of 12 groups with one untreated group being left as the control (Group I - control; given normal saline (NS)). The other groups were: Group II (ulcer+NS); Group III (5mg/kg sildenafil citrate, low dose); Group IV (10mg/kg sildenafil citrate, high dose); Group V (0.6mg/kg heparin, low dose); Group VI (6mg/kg heparin, high dose); Group VII (20nmol/kg des-acyl ghrelin); Group VIII (40nmol/kg des-acyl ghrelin); Group IX (4nmol/kg acyl ghrelin); Group X (8nmol/kg acly ghrelin); Group XI (20pmol/kg Nesfatin-1); Group XII (15nmol/kg Obestatin) and Group XIII (5nmol/kg Neuropeptide Y). Gastric neuropeptide expression was measured using an immunohistochemical method, and the amount in circulation was detected using ELISA. To compare with no treatment, the controls and other treatment groups, we recorded loss of the surface epithelium of the stomach, erosion, bleeding and inflammatory cell infiltration in the upper halves of the gastric glands. The muscularis and the layers beneath it were, however, apparently normal. The gastric mucosa healed with little or no inflammation when sildenafil citrate, low dose heparin, ghrelin, NUCB2/Nesfatin-1, obestatin, Neuropeptide Y were administered. Overall the data indicate that low dose heparin, and especially sildenafil citrate and neuropeptides, can be used clinically as an alternative approach in the treatment of the gastric ulcer. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. Follow-up of rheumatic carditis using 67Ga-citrate imaging

    International Nuclear Information System (INIS)

    Calegaro, J.U.M.; Bae, S.H.; Prado, E.S.; Gomes, E.F.

    2002-01-01

    Aim: This study reports the follow -up of 25 patients (pts) with rheumatic carditis (9 male, 16 females; 4-29 years, mean 12,12) using 67-gallium citrate. Materials and Methods: the pts were divided in 2 groups: I- first attack (7pts, 2 males, with a mean follow-up of 5,65 years); II- recurrence (18 pts, 7 males, with a mean follow-up of 5,27 years).Images of the thorax and semi quantitative indexes were obtained 72 hours after intravenous injection of 37-74 MBq (1-2 mCi) of 67-gallium citrate, using a LFOV scintillation camera. 67-gallium uptake in the cardiac area was graded as mild, moderate or severe using the tracer uptake in the lung as a reference (normal up to 130%). Results: all pts in group I (2 severe, 2 moderate, and 3 mild carditis) had normal gallium uptake in up to 9 weeks after the institution of cortico therapy, with a better outcome in follow-up.In group II, 8 pts presented moderately active carditis (2 had good and 6 had a poor outcome) and 10 mildly active carditis (7 had good and 3 had poor outcome). The evolution of the disease was better in 8 pts that the reduction of 67- gallium uptake to normal limits occurred in up to 9 weeks, than in 9 pts that the scintigraphy was only normal after 10 weeks of therapy. Conclusion: normal gallium uptake in up to 9 weeks of treatment seems to be a good predictor of evolution in rheumatic carditis first attack or recurrence; in recurrence, reduction of 67-gallium uptake only after 10 weeks or increasing uptake seems to be worse predictors

  11. Cardiac Ischemia Reperfusion Injury Following Instillation of 20 nm Citrate-capped Nanosilver

    Energy Technology Data Exchange (ETDEWEB)

    Becak DP, Holland NA; Shannahan, Jonathan H.

    2015-01-01

    Background: Silver nanoparticles (AgNP) have garnered much interest due to their antimicrobial properties, becoming one of the most utilized nano scale materials. However, any potential evocable cardiovascular injury associated with exposure has not been previously reported. We have previously demonstrated expansion of myocardial infarction after intratracheal (IT) instillation of other nanomaterials. We hypothesized that pulmonary exposure to Ag core AgNP induces persistent increase in circulating cytokines, expansion of cardiac ischemia-reperfusion (I/R) injury and associated with altered coronary vessel reactivity. Methods: Male Sprague-Dawley rats were exposed to 200 µg of 20 nm citrate capped Ag core AgNP, or a citrate vehicle intratracheally (IT). One and 7 days following IT instillation lungs were evaluated for inflammation and silver presence, serum was analyzed for concentrations of selected cytokines, and cardiac I/R injury and coronary artery reactivity was assessed. Results: AgNP instillation resulted in modest pulmonary injury with detection of silver in lung tissue and infiltrating cells, elevation of serum cytokines: G-CSF, MIP-1α, IL-1β, IL-2, IL-6, IL-13, IL-10, IL-18, IL-17, TNFα, and RANTES, expansion of I/R injury and depression of the coronary vessel reactivity at 1 day post IT compared to vehicle treated rats. Seven days post IT instillation was associated with persistent detection of silver in lungs, elevation in cytokines: IL-2, IL-13, and TNFα and expansion of I/R injury. Conclusions: Based on these data, IT instillation of AgNP increases circulating levels of several cytokines, which may contribute to persistent expansion of I/R injury possibly through an impaired vascular responsiveness.

  12. 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.

  13. [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.

  14. 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.

  15. 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

  16. 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...

  17. 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.

  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. Influence of current density on surface morphology and properties of pulse plated tin films from citrate electrolyte

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, Ashutosh; Bhattacharya, Sumit; Das, Siddhartha; Das, Karabi, E-mail: karabi@metal.iitkgp.ernet.in

    2014-01-30

    Bulk polycrystalline tin films have been processed by pulse electrodeposition technique from a simple solution containing triammonium citrate and stannous chloride. The cathodic investigations have been carried out by galvanostatic methods. As deposited samples are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). XRD analysis of the deposited films shows microcrystalline grains having β-Sn form. The surface morphology is very rough at lower current density, but becomes smooth at higher current density, and exhibits pyramid type morphology at all the current densities. The effect of current density on microhardness, melting behavior, and electrical resistivity are also reported here.

  20. Hydrokinetic simulations of nanoscopic precursor films in rough channels

    International Nuclear Information System (INIS)

    Chibbaro, S; Biferale, L; Binder, K; Milchev, A; Dimitrov, D; Diotallevi, F; Succi, S

    2009-01-01

    We report on simulations of capillary filling of highly wetting fluids in nanochannels with and without obstacles. We use atomistic (molecular dynamics) and hydrokinetic (lattice Boltzmann; LB) approaches which indicate clear evidence of the formation of thin precursor films, moving ahead of the main capillary front. The dynamics of the precursor films is found to obey a square-root law like that obeyed by the main capillary front, z 2 (t)∝t, although with a larger prefactor, which we find to take the same value for the different geometries (2D–3D) under inspection. The two methods show a quantitative agreement which indicates that the formation and propagation of thin precursors can be handled at a mesoscopic/hydrokinetic level. This can be considered as a validation of the LB method and opens the possibility of using hydrokinetic methods to explore space–time scales and complex geometries of direct experimental relevance. Then, the LB approach is used to study the fluid behaviour in a nanochannel when the precursor film encounters a square obstacle. A complete parametric analysis is performed which suggests that thin-film precursors may have an important influence on the efficiency of nanochannel-coating strategies

  1. Non radioactive precursor import into chloroplasts

    International Nuclear Information System (INIS)

    Lombardo, V.A.; Ottado, J.

    2003-01-01

    Full text: Eukaryotic cells have a subcellular organization based on organelles. Protein transport to these organelles is quantitatively important because the majority of cellular proteins are codified in nuclear genes and then delivered to their final destination. Most of the chloroplast proteins are translated on cytoplasmic ribosomes as larger precursors with an amino terminal transit peptide that is necessary and sufficient to direct the precursor to the chloroplast. Once inside the organelle the transit peptide is cleaved and the mature protein adopts its folded form. In this work we developed a system for the expression and purification of the pea ferredoxin-NADP + reductase precursor (preFNR) for its import into chloroplasts in non radioactive conditions. We constructed a preFNR fused in its carboxy terminus to a 6 histidines peptide (preFNR-6xHis) that allows its identification using a commercial specific antibody. The construction was expressed, purified, processed and precipitated, rendering a soluble and active preFNR-6xHis that was used in binding and import into chloroplasts experiments. The reisolated chloroplasts were analyzed by SDS-PAGE, electro-blotting and revealed by immuno-detection using either colorimetric or chemiluminescent reactive. We performed also import experiments labeling preFNR and preFNR-6xHis with radioactive methionine as controls. We conclude that preFNR-6xHis is bound and imported into chloroplasts as the wild type preFNR and that both colorimetric or chemiluminescent detection methods are useful to avoid the manipulation of radioactive material. (author)

  2. 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.

  3. 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%.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. Identification of residual leukemic cells by flow cytometry in childhood B-cell precursor acute lymphoblastic leukemia: verification of leukemic state by flow-sorting and molecular/cytogenetic methods

    DEFF Research Database (Denmark)

    Obro, Nina F; Ryder, Lars P; Madsen, Hans O

    2012-01-01

    Reduction in minimal residual disease, measured by real-time quantitative PCR or flow cytometry, predicts prognosis in childhood B-cell precursor acute lymphoblastic leukemia. We explored whether cells reported as minimal residual disease by flow cytometry represent the malignant clone harboring...... clone-specific genomic markers (53 follow-up bone marrow samples from 28 children with B-cell precursor acute lymphoblastic leukemia). Cell populations (presumed leukemic and non-leukemic) were flow-sorted during standard flow cytometry-based minimal residual disease monitoring and explored by PCR and....../or fluorescence in situ hybridization. We found good concordance between flow cytometry and genomic analyses in the individual flow-sorted leukemic (93% true positive) and normal (93% true negative) cell populations. Four cases with discrepant results had plausible explanations (e.g. partly informative...

  10. Polymeric precursors method for obtaining pigments based on Inorganic oxides of chromium and iron deposited on TiO{sub 2}; Metodo dos precursores polimericos para obtencao de pigmentos inorganicos a base de oxidos de cromo e de ferro, depositados sobre TiO{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2011-07-01

    The case study was the use of chromium oxides and iron, as a precursor in the synthesis of inorganic pigments. The synthesis was based on the dissolution of citric acid as a complexing agent, addition of metal oxides, such as ion chromophores; polymerization with ethylene glycol and doping with titanium oxide. Going through pre-calcination, breakdown, calcination at different temperatures (700, 900 and 1100 deg C resulting in pigments: green for pigment and chromium deposited on TiO2, orange for iron on TiO2. The thermal analysis (TG and DTA), evaluated their thermal decompositions, the XRD revealed the formation of crystalline phases such as iron titanate and chrome titanate; SEM showed the formation of hexagonal particles for both oxides. Under the different analysis, one can see the potential stability of pigments and powders, can be proposed its use as pigments in polymers. (author)

  11. Synthesis of aluminum oxide by the polymer precursor method (Pechini) in 4: 1 ratio of citric acid: metal cation: calcination temperature effect; Sintese do oxido de aluminio pelo metodo dos precursores polimericos (Pechini) na relacao 4:1 de acido citrico: cation metalico: efeito da temperatura de calcinacao

    Energy Technology Data Exchange (ETDEWEB)

    Silva, M.C.; Lira, H.L.; Ribeiro, P.C.; Freitas, N.L., E-mail: mirelecsilva@hotmail.com [Universidade Federal de Campina Grande (UFCG), PB (Brazil). Unidade Academica de Engenharia de Materiais

    2014-07-01

    The technology field is nanopowders prominent in science since these materials fall in various sectors regarding their applications. This work aims at the synthesis of aluminum oxide by polymeric precursors in 4:1 ratio of citric acid:metal cation and evaluate the influence of calcination temperature on their structural and morphological characteristics. The samples after reaction were characterized by XRD and thermal analysis. After calcination 500-1200°C the samples were characterized by XRD, SEM and particle size distribution. The results showed that the variation of the calcination temperature is sufficient to achieve a same material with different structural and morphological characteristics. The most stable phase aluminum oxide arose only after calcination at 1100°C, below 900°C, the amorphous material appeared. As regards the morphology, the change was not as significant as compared to the structure. (author)

  12. Radon as an earthquake precursor

    International Nuclear Information System (INIS)

    Planinic, J.; Radolic, V.; Vukovic, B.

    2004-01-01

    Radon concentrations in soil gas were continuously measured by the LR-115 nuclear track detectors during a four-year period. Seismic activities, as well as barometric pressure, rainfall and air temperature were also observed. The influence of meteorological parameters on temporal radon variations was investigated, and a respective equation of the multiple regression was derived. The earthquakes with magnitude ≥3 at epicentral distances ≤200 km were recognized by means of radon anomaly. Empirical equations between earthquake magnitude, epicentral distance and precursor time were examined, and respective constants were determined

  13. Radon as an earthquake precursor

    Energy Technology Data Exchange (ETDEWEB)

    Planinic, J. E-mail: planinic@pedos.hr; Radolic, V.; Vukovic, B

    2004-09-11

    Radon concentrations in soil gas were continuously measured by the LR-115 nuclear track detectors during a four-year period. Seismic activities, as well as barometric pressure, rainfall and air temperature were also observed. The influence of meteorological parameters on temporal radon variations was investigated, and a respective equation of the multiple regression was derived. The earthquakes with magnitude {>=}3 at epicentral distances {<=}200 km were recognized by means of radon anomaly. Empirical equations between earthquake magnitude, epicentral distance and precursor time were examined, and respective constants were determined.

  14. Identification of residual leukemic cells by flow cytometry in childhood B-cell precursor acute lymphoblastic leukemia: verification of leukemic state by flow-sorting and molecular/cytogenetic methods.

    Science.gov (United States)

    Øbro, Nina F; Ryder, Lars P; Madsen, Hans O; Andersen, Mette K; Lausen, Birgitte; Hasle, Henrik; Schmiegelow, Kjeld; Marquart, Hanne V

    2012-01-01

    Reduction in minimal residual disease, measured by real-time quantitative PCR or flow cytometry, predicts prognosis in childhood B-cell precursor acute lymphoblastic leukemia. We explored whether cells reported as minimal residual disease by flow cytometry represent the malignant clone harboring clone-specific genomic markers (53 follow-up bone marrow samples from 28 children with B-cell precursor acute lymphoblastic leukemia). Cell populations (presumed leukemic and non-leukemic) were flow-sorted during standard flow cytometry-based minimal residual disease monitoring and explored by PCR and/or fluorescence in situ hybridization. We found good concordance between flow cytometry and genomic analyses in the individual flow-sorted leukemic (93% true positive) and normal (93% true negative) cell populations. Four cases with discrepant results had plausible explanations (e.g. partly informative immunophenotype and antigen modulation) that highlight important methodological pitfalls. These findings demonstrate that with sufficient experience, flow cytometry is reliable for minimal residual disease monitoring in B-cell precursor acute lymphoblastic leukemia, although rare cases require supplementary PCR-based monitoring.

  15. Fluorinated Phenylalanine Precursor Resistance in Yeast

    Directory of Open Access Journals (Sweden)

    Ian S. Murdoch

    2018-06-01

    Full Text Available Development of a counter-selection method for phenylalanine auxotrophy could be a useful tool in the repertoire of yeast genetics. Fluorinated and sulfurated precursors of phenylalanine were tested for toxicity in Saccharomyces cerevisiae. One such precursor, 4-fluorophenylpyruvate (FPP, was found to be toxic to several strains from the Saccharomyces and Candida genera. Toxicity was partially dependent on ARO8 and ARO9, and correlated with a strain’s ability to convert FPP into 4-fluorophenylalanine (FPA. Thus, strains with deletions in ARO8 and ARO9, having a mild phenylalanine auxotrophy, could be separated from a culture of wild-type strains using FPP. Tetrad analysis suggests FPP resistance in one strain is due to two genes. Strains resistant to FPA have previously been shown to exhibit increased phenylethanol production. However, FPP resistant isolates did not follow this trend. These results suggest that FPP could effectively be used for counter-selection but not for enhanced phenylethanol production.

  16. Hair sheep blood, citrated or defibrinated, fulfills all requirements of blood agar for diagnostic microbiology laboratory tests.

    Directory of Open Access Journals (Sweden)

    Ellen Yeh

    Full Text Available BACKGROUND: Blood agar is used for the identification and antibiotic susceptibility testing of many bacterial pathogens. In the developing world, microbiologists use human blood agar because of the high cost and inhospitable conditions for raising wool sheep or horses to supply blood. Many pathogens either fail to grow entirely or exhibit morphologies and hemolytic patterns on human blood agar that confound colony recognition. Furthermore, human blood can be hazardous to handle due to HIV and hepatitis. This study investigated whether blood from hair sheep, a hardy, low-maintenance variety of sheep adapted for hot climates, was suitable for routine clinical microbiology studies. METHODS AND FINDINGS: Hair sheep blood obtained by jugular venipuncture was anticoagulated by either manual defibrination or collection in human blood bank bags containing citrate-phosphate-dextrose. Trypticase soy 5% blood agar was made from both forms of hair sheep blood and commercial defibrinated wool sheep blood. Growth characteristics, colony morphologies, and hemolytic patterns of selected human pathogens, including several streptococcal species, were evaluated. Specialized identification tests, including CAMP test, reverse CAMP test, and satellite colony formation with Haemophilus influenzae and Abiotrophia defectiva were also performed. Mueller-Hinton blood agar plates prepared from the three blood types were compared in antibiotic susceptibility tests by disk diffusion and E-test. CONCLUSIONS: The results of all studies showed that blood agar prepared from citrated hair sheep blood is suitable for microbiological tests used in routine identification and susceptibility profiling of human pathogens. The validation of citrated hair sheep blood eliminates the labor-intensive and equipment-requiring process of manual defibrination. Use of hair sheep blood, in lieu of human blood currently used by many developing world laboratories and as an alternative to cost

  17. In silico modeling and experimental evidence of coagulant protein interaction with precursors for nanoparticle functionalization.

    Science.gov (United States)

    Okoli, Chuka; Sengottaiyan, Selvaraj; Arul Murugan, N; Pavankumar, Asalapuram R; Agren, Hans; Kuttuva Rajarao, Gunaratna

    2013-10-01

    The design of novel protein-nanoparticle hybrid systems has applications in many fields of science ranging from biomedicine, catalysis, water treatment, etc. The main barrier in devising such tool is lack of adequate information or poor understanding of protein-ligand chemistry. Here, we establish a new strategy based on computational modeling for protein and precursor linkers that can decorate the nanoparticles. Moringa oleifera (MO2.1) seed protein that has coagulation and antimicrobial properties was used. Superparamagnetic nanoparticles (SPION) with precursor ligands were used for the protein-ligand interaction studies. The molecular docking studies reveal that there are two binding sites, one is located at the core binding site; tetraethoxysilane (TEOS) or 3-aminopropyl trimethoxysilane (APTES) binds to this site while the other one is located at the side chain residues where trisodium citrate (TSC) or Si60 binds to this site. The protein-ligand distance profile analysis explains the differences in functional activity of the decorated SPION. Experimentally, TSC-coated nanoparticles showed higher coagulation activity as compared to TEOS- and APTES-coated SPION. To our knowledge, this is the first report on in vitro experimental data, which endorses the computational modeling studies as a powerful tool to design novel precursors for functionalization of nanomaterials; and develop interface hybrid systems for various applications.

  18. Fluorescing macerals from wood precursors

    Energy Technology Data Exchange (ETDEWEB)

    Stout, S A; Bensley, D F

    1987-01-01

    A preliminary investigation into the origin of wood-derived macerals has established the existence of autofluorescent maceral precursors in the secondary xylem of swamp-inhabiting plant species. The optical character and fluorescent properties of microtomed thin-sections of modern woods from the Florida Everglades and Okefenokee Swamp, Georgia are compared to the character and properties of their peatified equivalents from various Everglades and Okefenokee peat horizons and their lignitic equivalents from the Brandon lignite of Vermont and the Trail Ridge lignitic peat from northern Florida. The inherent fluorescence of woody cell walls is believed to be caused by lignin though other cell wall components may contribute. The fluorescence spectra for several wood and cell types had a ..gamma../sub m//sub a//sub x/ of 452 nm and Q value of 0.00. The color as observed in blue light and the spectral geometry as measured in UV light of peatified and lignitic woody cell walls (potential textinites) may change progressively during early coalification. Cell wall-derived maceral material is shown to maintain its fluorescing properties after being converted to a structureless material, perhaps a corpohuminite or humodetrinite precursor. Fluorescing xylem cell contents, such as condensed tannins or essential oils, can maintain the fluorescent character through early coalification. Xylem cell walls and xylem cell contents are shown to provide fluorescing progenitor materials which would not require subsequent infusion with 'lipid' materials to account for their fluorescence as phytoclast material or as macerals in coal. 35 references.

  19. Preparation of Tc-99m human serum albumin using stannous citrate and stannous chloride

    International Nuclear Information System (INIS)

    El-Asrag, H.A.; El-Wetery, A.S.; El-Mohty, A.A.

    1988-01-01

    99mTc-albumin is widely used as radioactive indicator in the measurement of cardiac output by external counting techniques and in blood volume studies. The quality of 99mTc-albumin depends on the method of preparation. A comparative study had been carried out on the 99mTc-albumin preparation by the stannous chloride, stannous tartarate and stannous citrate method. The different parameters investigated for each method include: pH, albumin concentration, reductant concentration and ascorbic acid as antioxidant stabilizer. The biological distribution of 99mTc-albumin, prepared by different methods, were determined in mice and rats. A procedure was developed for the preparation of stannous human serum albumin (HSA) kit for human application the kit provides a freeze dried sterile formulation for reconstitution with sterile 99mTc pertechnetate solution to give 99mTc-Hsa, the effect of irradiation sterilization on the freeze dried kit was studied by spectrophotometric determination and biological distribution in mice and rats

  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. 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.

  4. Differentiation of malignant and degenerative benign bone disease using Tc-99m Citrate and Tc-99m MDP scintigraphy

    International Nuclear Information System (INIS)

    Jin, J.; Guo, R.; Li, S.-J.; Ren, Y.; Zhang, C.; Zhang, X.

    2007-01-01

    Full text: For the evaluation of bone metastases in patients (pts) with cancer, 99mTcMDP bone scintigraphy is an important tool, but some limitations exist. One of these is the differential diagnosis of malignant and degenerative benign bone disease. The aim of this study was to differentiate them using 99mTcCitrate and 99mTcMDP scintigraphy. Methods: 39 pts (92 lesions) with known malignant or degenerative benign bone disease were studied. 23 pts had malignant bone disease (48 lesions, group 1), the other 16 pts had degenerative benign bone disease (44 lesions, group2), for which the results of 99mTcMDP scintigraphy were positive. In both groups, 99mTcCitrate scintigraphy was performed within a time interval of 2-7 days after 99mTcMDP scintigraphy (555∼740MBq. static, 3hr, planar or SPECT i m a g e s w h e n r e q u i r e d ) . The 99mTccitrate/99mTcMDP lesion-to-background radioisotope uptake ratio (RUR) was calculated for each lesion. Conventional techniques (histopathology, X-ray, CT, MRI and clinical follow up) were considered to be proof of the presence of bone metastases and degenerative benign bone disease. Results: Uptake of 99mTcMDP in the two groups is the same (1.96±0.25 vs. 1.87±0.21; t=1.178, P>0.20), while in 99mTcCitrate image, malignant lesions demonstrated a higher uptake of lesion activity than that of benign degenerative lesions (1.47±0.42 vs. 1.09±0.38; t=2.887, P<0.01). The mean 99mTccitrate/99mTcMDP RUR in the malignant group was significantly higher than the mean in the benign group (0.78±0.21 vs. 0.54±0.19; t=3.646, P<0.001). Conclusions: The preliminary results of the study confirm the usefulness and feasibility of 99mTcCitrate scintigraphy for differentiating malignant from benign degenerative lesions seen as areas of increased activity on 99mTcMDP bone scintigraphy. (author)

  5. Pregnancy rate of gonadotrophin therapy and laparoscopic ovarian electrocautery in polycystic ovary syndrome resistant to clomiphene citrate: a comparative study

    Directory of Open Access Journals (Sweden)

    Ghafarnegad M

    2010-01-01

    Full Text Available "n Normal 0 false false false EN-US X-NONE AR-SA MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:Arial; mso-bidi-theme-font:minor-bidi;} Background: Polycystic ovary syndrome (PCOS is a common cause of ovulation insufficiency and then infertility. Therapeutic options to induce ovulation in anovulatory PCOS patients are clomiphene citrate, metformin, tamoxifen, dopamine agonists (bromocriptin, Gonadotrophin and laparoscopic ovarian electrocautery (LOE. Gonadotrophin and LOE are important options in anovulatory clomiphene citrate-resistant patients with PCOS. Literature data regarding compare of the efficacy of these two treatments are few. Therefore we aimed to study the pregnancy rates of these treatments in infertile clomiphene citrate-resistant patients with PCOS."n"nMethods: A randomized clinical trial study was carried out in infertile clomiphene citrate-resistant patients with PCOS, referred to infertility clinic of Mirza Koochackhan Hospital of Tehran University of Medical Science in Tehran, Iran, between 2003 and 2008."n"nResults: A total of 100 patients women were randomly allocated in two groups. There were no differences in age and pimary and secondary infertility duration. In LOE treatment group, eight cases (16% were pregnant and all delivered at term. in gonadotrophin treatment 14 cases (28% were pregnant, 10 cases (20% delivered at term

  6. Gas response properties of citrate gel synthesized nanocrystalline MgFe2O4: Effect of sintering temperature

    International Nuclear Information System (INIS)

    Patil, J.Y.; Mulla, I.S.; Suryavanshi, S.S.

    2013-01-01

    Graphical abstract: Display Omitted Highlights: ► Synthesis of nanocrystalline MgFe 2 O 4 by economical citrate gel combustion method. ► Structural, morphological, and gas response properties of MgFe 2 O 4 . ► Enhancement in selectivity of MgFe 2 O 4 towards LPG with sintering temperature. ► Use of MgFe 2 O 4 to detect different gases at different operating temperatures. -- Abstract: Spinel type MgFe 2 O 4 material was synthesized by citrate gel combustion method. The effect of sintering temperature on structural, morphological, and gas response properties was studied. The powder X-ray diffraction pattern and transmission electron microscope study confirms nanocrystalline spinel structure of the synthesized powder. The material was tested for response properties to various reducing gases like liquid petroleum gas (LPG), acetone, ethanol, and ammonia. The results demonstrated n-type semiconducting behavior of MgFe 2 O 4 material. It was revealed that MgFe 2 O 4 sintered at 973 K was most sensitive to LPG at 648 K and to acetone at 498 K. However MgFe 2 O 4 sintered at 1173 K exhibited higher response and selectivity to LPG with marginal increase in the operating temperature. Furthermore, the sensor exhibited a fast response and a good recovery. It was observed that the particles size, porosity, and surface activity of the sensor material is affected by the sintering temperature.

  7. 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.)

  8. 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.

  9. 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.

  10. Synthesis, sintering and dissolution of thorium and uranium (IV) mixed oxide solid solutions: influence of the method of precursor preparation; Synthese, frittage et caracterisation de solutions solides d'oxydes mixtes de thorium et d'uranium (IV): influence de la methode de preparation du precurseur

    Energy Technology Data Exchange (ETDEWEB)

    Hingant, N

    2008-12-15

    Mixed actinide dioxides are currently considered as potential fuels for the third and fourth generations of nuclear reactors. In this context, thorium-uranium (IV) dioxide solid solutions were studied as model compounds to underline the influence of the method of preparation on their physico-chemical properties. Two methods of synthesis, both based on the initial precipitation of oxalate precursors have been developed. The first consisted in the direct precipitation ('open' system) while the second involved hydrothermal conditions ('closed' system). The second method led to a significant improvement in the crystallization of the samples especially in the field of the increase of the grain size. In these conditions, the formation of a complete solid solution Th{sub 1-x}U{sub x}(C{sub 2}O{sub 4}){sub 2}.2H{sub 2}O was prepared between both end-members. Its crystal structure was also resolved. Whatever the initial method considered, these compounds led to the final dioxides after heating above 400 C. The various steps associated to this transformation, involving the dehydration of precursors then the decomposition of oxalate groups have been clarified. Moreover, the use of wet chemistry methods allowed to reduce the sintering temperature of the final thorium-uranium (IV) dioxide solid solutions. Whatever the method of preparation considered, dense samples (95% to 97% of the calculated value) were obtained after only 3 hours of heating at 1500 C. Additionally, the use of hydrothermal conditions significantly increased the grain size, leading to the reduction of the occurrence of the grain boundaries and of the global residual porosity. The significant improvement in the homogeneity of cations distribution in the samples was also highlighted. Finally, the chemical durability of thorium-uranium (IV) dioxide solid solutions was evaluated through the development of leaching tests in nitric acid. The optimized homogeneity especially in terms of the

  11. Fluid Mechanics of Lean Blowout Precursors in Gas Turbine Combustors

    Directory of Open Access Journals (Sweden)

    T. M. Muruganandam

    2012-03-01

    Full Text Available Understanding of lean blowout (LBO phenomenon, along with the sensing and control strategies could enable the gas turbine combustor designers to design combustors with wider operability regimes. Sensing of precursor events (temporary extinction-reignition events based on chemiluminescence emissions from the combustor, assessing the proximity to LBO and using that data for control of LBO has already been achieved. This work describes the fluid mechanic details of the precursor dynamics and the blowout process based on detailed analysis of near blowout flame behavior, using simultaneous chemiluminescence and droplet scatter observations. The droplet scatter method represents the regions of cold reactants and thus help track unburnt mixtures. During a precursor event, it was observed that the flow pattern changes significantly with a large region of unburnt mixture in the combustor, which subsequently vanishes when a double/single helical vortex structure brings back the hot products back to the inlet of the combustor. This helical pattern is shown to be the characteristic of the next stable mode of flame in the longer combustor, stabilized by double helical vortex breakdown (VBD mode. It is proposed that random heat release fluctuations near blowout causes VBD based stabilization to shift VBD modes, causing the observed precursor dynamics in the combustor. A complete description of the evolution of flame near the blowout limit is presented. The description is consistent with all the earlier observations by the authors about precursor and blowout events.

  12. 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.

  13. 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)

  14. 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

  15. Differentiation of Mouse Embryonic Stem Cells into Ventral Foregut Precursors

    DEFF Research Database (Denmark)

    Rothová, Michaela; Hölzenspies, Jurriaan J; Livigni, Alessandra

    2016-01-01

    Anterior definitive endoderm (ADE), the ventral foregut precursor, is both an important embryonic signaling center and a unique multipotent precursor of liver, pancreas, and other organs. Here, a method is described for the differentiation of mouse embryonic stem cells (mESCs) to definitive...... endoderm with pronounced anterior character. ADE-containing cultures can be produced in vitro by suspension (embryoid body) culture or in a serum-free adherent monolayer culture. ESC-derived ADE cells are committed to endodermal fates and can undergo further differentiation in vitro towards ventral foregut...

  16. Sequestration of Sr-90 Subsurface Contamination in the Hanford 100-N Area by Surface Infiltration of a Ca-Citrate-Phosphate Solution

    Energy Technology Data Exchange (ETDEWEB)

    Szecsody, James E.; Rockhold, Mark L.; Oostrom, Martinus; Moore, R. C.; Burns, Carolyn A.; Williams, Mark D.; Zhong, Lirong; Fruchter, Jonathan S.; McKinley, James P.; Vermeul, Vincent R.; Covert, Matthew A.; Wietsma, Thomas W.; Breshears, Andrew T.; Garcia, Ben J.

    2009-03-01

    The objective of this project is to develop a method to emplace apatite precipitate in the 100N vadose zone, which results in sorption and ultimately incorporation of Sr-90 into the apatite structure. The Ca-citrate-PO4 solution can be infiltrated into unsaturated sediments to result in apatite precipitate to provide effective treatment of Sr-90 contamination. Microbial redistribution during solution infiltration and a high rate of citrate biodegradation for river water microbes (water used for solution infiltration) results in a relatively even spatial distribution of the citrate biodegradation rate and ultimately apatite precipitate in the sediment. Manipulation of the Ca-citrate-PO4 solution infiltration strategy can be used to result in apatite precipitate in the lower half of the vadose zone (where most of the Sr-90 is located) and within low-K layers (which are hypothesized to have higher Sr-90 concentrations). The most effective infiltration strategy to precipitate apatite at depth (and with sufficient lateral spread) was to infiltrate a high concentration solution (6 mM Ca, 15 mM citrate, 60 mM PO4) at a rapid rate (near ponded conditions), followed by rapid, then slow water infiltration. Repeated infiltration events, with sufficient time between events to allow water drainage in the sediment profile can be used to buildup the mass of apatite precipitate at greater depth. Low-K heterogeneities were effectively treated, as the higher residual water content maintained in these zones resulted in higher apatite precipitate concentration. High-K zones did not receive sufficient treatment by infiltration, although an alternative strategy of air/surfactant (foam) was demonstrated effective for targeting high-K zones. The flow rate manipulation used in this study to treat specific depths and heterogeneities are not as easy to implement at field scale due to the lack of characterization of heterogeneities and difficulty tracking the wetting front over a large

  17. A study on 99Tcm-citrate and 99Tcm (V)-DMSA imaging in the diagnosis of acute purulent osteoarthritis

    International Nuclear Information System (INIS)

    Wu Zhaozhong; Lin Wei; Wu Hengfu; Wu Changwei; Yuan Gewen; Fan Ziwen; Wu Boyi

    2003-01-01

    Objective: To assess the clinical diagnostic value of 99 Tc m -citrate and 99 Tc m (1/2ae)-dimercaptosuccinic acid (DMSA) imaging in the acute purulent osteoarthritis. Methods: Seventeen patients with confirmed acute purulent osteoarthritis and nineteen patients with non-purulent osteoarthritis were studied. In all patients, 99 Tc m -methylene diphosphonic acid (MDP), 99 Tc m -citrate and 99 Tc m (1/2ae)-DMSA imaging were sequentially performed and the images were analyzed semiquantitatively. Results: In the acute purulent osteoarthritis group, there were positive bonetactic accumulations at certain areas on the three kinds of imaging. In the non-purulent osteoarthritis group, 99 Tc m -MDP and 99 Tc m (1/2ae)-DMSA imaging showed clear bonetactic accumulation, but 99 Tc m -citrate imaging showed only light bonetactic accumulation in addition to the accumulations in soft tissue at certain areas. Lesion to nonlesion ratio (L/N=2.300±0.094) of acute purulent osteoarthritis was greater than that in non-purulent osteoarthritis group (1.298±0.054, P 99 Tc m -citrate imaging, and there was no significant difference between two groups on 99 Tc m (1/2ae)-DMSA imaging (L/N ratio of acute purulent osteoarthritis group was 3.495±0.180, and L/N ratio of non-purulent osteoarthritis group was 3.091±0.091, P>0.05). Conclusions: To diagnose the bone inflammation, 99 Tc m -citrate imaging coalesced with 99 Tc m -MDP or 99 Tc m (1/2ae)-DMSA imaging can help to evaluate the pathologic and physiologic progresses in bone inflammatory areas, at the same time , the information by 99 Tc m -citrate imaging is telling the actual inflammation areas, and that by 99 Tc m (1/2ae)-DMSA and 99 Tc m -MDP imaging is about the response to the increase of bone metabolism

  18. Early postradiation recovery of precursor cells of hemopoietic stroma

    International Nuclear Information System (INIS)

    Todriya, T.V.

    1984-01-01

    Ability of stroma precursor cells to early postradiation recovery was studied in male mices using the method of fraction irradiation of bone marrow. Donor mices of bone marrow were irradiated in vivo once by the total dose (nonfraction irradiation) and fractionally with 6 h interval between two irradiation doses. The cumulative irradiation doses equal to 10, 12, 14, 16 Gr were investigated. Irradiation was carried out using gamma facility. Bone marrow of the femur was implanted immediately after irradiation under kidney capsule of nonirradiated syngeneic recipient. The ability of stroma precursor cells to intracellular repair (repair index) was evaluated according to the ratio of the number of hemopoietic cells formed in heterotropic transplants in groups with fraction irradiation to the same one in groups with nonfraction irradiation. The obtained results testify to the fact that slowly regenerated highly radioresistant population of precursor cells of hemopoietic stroma is capable to early postradiation recovery

  19. Precursors to suicidality and violence on antidepressants

    DEFF Research Database (Denmark)

    Bielefeldt, Andreas Ø; Danborg, Pia B; Gøtzsche, Peter C

    2016-01-01

    OBJECTIVE: To quantify the risk of suicidality and violence when selective serotonin and serotonin-norepinephrine reuptake inhibitors are given to adult healthy volunteers with no signs of a mental disorder. DESIGN: Systematic review and meta-analysis. MAIN OUTCOME MEASURE: Harms related...... to suicidality, hostility, activation events, psychotic events and mood disturbances. SETTING: Published trials identified by searching PubMed and Embase and clinical study reports obtained from the European and UK drug regulators. PARTICIPANTS: Double-blind, placebo-controlled trials in adult healthy volunteers...... that reported on suicidality or violence or precursor events to suicidality or violence. RESULTS: A total of 5787 publications were screened and 130 trials fulfilled our inclusion criteria. The trials were generally uninformative; 97 trials did not report the randomisation method, 75 trials did not report any...

  20. Cell differentiation during sexual development of the fungus Sordaria macrospora requires ATP citrate lyase activity.

    Science.gov (United States)

    Nowrousian, M; Masloff, S; Pöggeler, S; Kück, U

    1999-01-01

    During sexual development, mycelial cells from most filamentous fungi differentiate into typical fruiting bodies. Here, we describe the isolation and characterization of the Sordaria macrospora developmental mutant per5, which exhibits a sterile phenotype with defects in fruiting body maturation. Cytological investigations revealed that the mutant strain forms only ascus precursors without any mature spores. Using an indexed cosmid library, we were able to complement the mutant to fertility by DNA-mediated transformation. A single cosmid clone, carrying a 3.5-kb region able to complement the mutant phenotype, has been identified. Sequencing of the 3.5-kb region revealed an open reading frame of 2.1 kb interrupted by a 66-bp intron. The predicted polypeptide (674 amino acids) shows significant homology to eukaryotic ATP citrate lyases (ACLs), with 62 to 65% amino acid identity, and the gene was named acl1. The molecular mass of the S. macrospora ACL1 polypeptide is 73 kDa, as was verified by Western blot analysis with a hemagglutinin (HA) epitope-tagged ACL1 polypeptide. Immunological in situ detection of the HA-tagged polypeptide demonstrated that ACL is located within the cytosol. Sequencing of the mutant acl1 gene revealed a 1-nucleotide transition within the coding region, resulting in an amino acid substitution within the predicted polypeptide. Further evidence that ACL1 is essential for fruiting body maturation comes from experiments in which truncated and mutated versions of the acl1 gene were used for transformation. None of these copies was able to reconstitute the fertile phenotype in transformed per5 recipient strains. ACLs are usually involved in the formation of cytosolic acetyl coenzyme A (acetyl-CoA), which is used for the biosynthesis of fatty acids and sterols. Protein extracts from the mutant strain showed a drastic reduction in enzymatic activity compared to values obtained from the wild-type strain. Investigation of the time course of ACL

  1. The laparoscopic ovarian electrocautery versus gonadotropin therapy in infertile women with clomiphene citrate-resistant polycystic ovary syndrome; a randomized controlled trial.

    Science.gov (United States)

    Mehrabian, Ferdous; Eessaei, Fatemeh

    2012-03-01

    This study aimed to compare two methods of treatment of infertility with gonadotropin with laparoscopic ovarian electrocauterization in patients with clomiphene citrate-resistant polycystic ovary syndrome (PCOS). A number of 104 nulipara patients with polycystic ovary syndrome, who were resistant to clomiphene citrate were randomly assigned to two groups. One group received gonadotropin; after the bleeding withdrawal and from the third day of the cycle, the injection of human menopausal gonadotropin (HMG) was started with 10 mg medroxy progesterone. The patients were followed with serial trans-vaginal sonographies. When the diameter of follicles reached to 18 mm, human chorionic gonadotropin (HCG) was prescribed. The other group was treated with laparoscopic ovarian electrocauterization under general anesthesia. If after 3 cycles, the anovulation was established with progesterone measurement, the clomiphene citrate was prescribed. Gonadotropin was administered, if the lack of ovulation persisted. No significant difference was documented between the two groups in terms of the obesity indexes, duration of infertility, age, sonographic and laboratory findings. In the gonadotropin group, 37 cases (71%) of pregnancy occurred. The rate of pregnancy was the same in the other group consisting of 18 cases treated by electrocautery, 9 cases with cautery + clomiphene, and 10 cases with clomiphene + cautery + gonadotropin. In the group treated with gonadotropin, there were 1 triple and 4 twins pregnancies. In the group treated with ovarian electrocautery, one twin pregnancy was observed. In the group treated with gonadotropin, 2 cases of ovarian hyperstimulation syndrome, 1 case of ectopic pregnancy and 6 cases of miscarriage occurred; the corresponding figure in the ovarian electrocautery group consisted of 5 cases of miscarriage. Our findings suggest that ovarian electrocauterization is an appropriate method with good efficacy and low complication rate for infertility

  2. Biochemistry of fluoroacetate poisoning: the isolation and some properties of the fluorotricarboxylic acid inhibitor of citrate metabolism

    Energy Technology Data Exchange (ETDEWEB)

    Peters, R; Wakelin, R W

    1953-01-01

    It has been suggested that the toxicity of fluoroacetate is due to the enzymic synthesis of a fluorotricarboxylic acid, which 'jams' the tricarboxylic acid cycle at the citrate stage. This communication presents the proof of this hypothesis. The inhibitory substance for citrate metabolism synthesized by enzymic action from fluoroacetate has been isolated as a compouud in crystalline form of great potency. Under the conditions of test it inhibits the disappearance of approximately 300 times its weight of citric acid in 30 min. The final isolation involved a separation from citric acid by the use of ion-exchange resin, and fractional extraction with ether. It is a monofluorotricarboxylic acid, as shown by its migration on a paper chromatogram, by its fluorine content (estimated spectrochemically), and by its titration curve. It does not give the colour reaction with sodium sulphide for pentabromacetone produced from citric acid by the usual methods. It gives an infra-red band which may be expected from a C-F bond. By a process of exclusion, it is considered to be a fluorocitric acid; a final decision must await synthesis.

  3. A prospective comparison of topical feracrylum citrate versus adrenaline as haemostatic agent in hypospadias surgery in children

    Directory of Open Access Journals (Sweden)

    Ashok Kumar Laddha

    2014-01-01

    Full Text Available Background: A comparative study of topical feracrylum citrate versus adrenaline to minimise haemorrhage-related complications in paediatric hypospadiac patients. Patients and Methods: A total of 108 consecutive paediatric hypospadiac patients (48 in the study group and 60 control - random allocation were studied. In the study group, 1% feracrylum citrate solution was used and adrenaline (1:100,000 in controls. Results: Among the study group, average number of blood-soaked gauge pieces were 2.95/patient, correlating with average intraoperative blood loss of 14.74 ml. In controls, average blood-soaked gauge pieces were 4.83/patient corresponding to an average blood loss of 24.13 ml. The average amount of blood loss during surgery in the <5 years was 13.70 ml/patient in the feracrylum group, while the same in the adrenaline group was 23.45 ml. Average duration of surgery was 79 min in the study group, while the same in controls was 94 min/patient. Average number of cauterisations was 0.255/patient in the study group and 0.583/patient among controls. Postoperative haematoma was seen in 8% study group compared with 18% controls. Wound oedema appeared in 4.17% study group and 11.67% controls. Postoperative complications were higher among controls. Conclusions: Feracrylum is more efficient and safer topical haemostatic agent than adrenaline. It reduced the frequency of cauterisation and tissue damage, intraoperative blood loss, and postoperative complications.

  4. Effect of regional citrate anticoagulation on critical patients with continuous renal replacement therapy

    Directory of Open Access Journals (Sweden)

    Li-Li You

    2016-12-01

    Full Text Available Objective: To investigate the efficacy and safety of regional citrate anticoagulation (RCA in continuous renal replacement therapy (CRRT for critical patients. Methods: A total of 83 critical patients need CRRT in the intensive care units of our hospital from July 2012 to June 2016 were recruited in the study, and the patients were divided into two groups randomly, the patients in observation group received the RCA treatment, and the patients in control group received traditional low molecular heparin anticoagulation. The difference of safety indicators, biochemical indicators, extracorporeal circulation blood coagulation condition and complications in patients were determined between two groups. Results: Compared with control group, the patients in observation group had an elevated level of iCa2+, the level of chloride ion reduced, the use time of filter increased, the bleeding cases reduced, the concentrations of urea nitrogen, creatinine TNF-α , IL-1β, IL-8 and NO were all significantly downregulated, the data have a significant difference (P < 0.05. Conclusions: RCA is a safe and effective method for CRRT in patients with a high risk of bleeding.

  5. Platelet concentrates stored in plasma for 72 hours at 22 degrees C prepared from buffycoats of citrate-phosphate-dextrose blood collected in a quadruple-bag saline-adenine-glucose-mannitol system

    NARCIS (Netherlands)

    Pietersz, R. N.; Loos, J. A.; Reesink, H. W.

    1985-01-01

    A method is described to prepare platelet concentrates from the buffycoat of citrate-phosphate-dextrose (CPD) blood in a closed four-bag system and to store the platelets in autologous plasma under sterile conditions. After separation of the blood into plasma, buffycoat and leukocyte- and

  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. Clinical usefulness of subtraction scintigraphy of the liver with Ga-67-citrate and Tc-99m-colloid

    International Nuclear Information System (INIS)

    Oyamada, H.; Terui, S.; Nagaiwa, K.; Kawai, H.; Fukukita, H.

    1983-01-01

    Subtraction scintigraphy of the liver with Ga-67-citrate and Tc-99m-colloid was performed for the radionuclide image diagnosis of intrahepatic masses, especially hepatoma. In this method the Tc-99m image was subtracted from the Ga-67 image. After normalizing both images, 4 different factors (0.6, 0.8, 1.0, and 1.2) were applied to the Tc-99m image before the subtraction. Finally, 4 subtraction images with different contrasts were obtained in one X-ray film. This method was found to be very useful in the assessment of intrahepatic focal accumulation of Ga-67, especially in cases with hepatoma, because it eliminated the uncertainty in the former method in which only visual judgment was done

  9. The theory of planned behavior: Precursors of marijuana use in early adolescence?

    NARCIS (Netherlands)

    Malmberg, M.; Overbeek, G.J.; Vermulst, A.A.; Monshouwer, K.; Vollebergh, W.A.M.; Engels, R.C.M.E.

    2012-01-01

    Background: Precursors of marijuana use in early adolescence are largely unknown because studies generally focus on marijuana use among older adolescents or adults. Methods: In this study, we examined precursors of marijuana use in a sample of 1023 Dutch early adolescents (aged 11-14 at Time 1) who

  10. Effect of clomiphene citrate on uterine hemodynamics in women with unexplained infertility

    Directory of Open Access Journals (Sweden)

    Omran E

    2018-04-01

    Full Text Available Eman Omran, Mohamed El-Sharkawy, Akmal El-Mazny, Mohamed Hammam, Wafaa Ramadan, Dina Latif, Dalia Samir, Sherine Sobh Department of Obstetrics and Gynecology, Kasr Al-Ainy Hospital, Cairo University, Cairo, Egypt Purpose: The aim of the study was to evaluate the effect of clomiphene citrate on uterine artery blood flow using pulsed Doppler and endometrial and subendometrial micro vascularization using 3D power Doppler in unexplained infertility. Patients and methods: In a prospective observational study at a university teaching hospital, the mid-luteal (peri-implantation endometrial thickness and volume, uterine artery pulsatility index (PI and resistance index (RI, endometrial and subendometrial vascularization index (VI, flow index (FI, and vascularization flow index (VFI, and serum estradiol and progesterone levels were compared between natural and clomiphene citrate stimulated cycles in the same group of 50 patients with unexplained infertility. Statistical analysis was done using paired t-test to compare different study variables. Results: The primary outcome, which was the endometrial flow index, was significantly lower in the stimulated cycles (mean ± SD: 23.89±7.96 vs 27.49±8.73, mean difference (95% CI: -3.6 (-2, -5.9; P=0.03. The mean ± SD of endometrial thickness (10.92±3.04 vs 12.46±3.08 mm; P=0.01, volume (4.57±1.28 vs 5.26±1.32 cm3; P=0.009, endometrial VI (0.86±0.15 vs 0.95%±0.21%; P=0.02, VFI (0.25±0.08 vs 0.31±0.12; P=0.004, subendometrial VI (1.93±0.68 vs 2.26%±0.75%; P=0.02, FI (26.81±9.16 vs 30.73±9.87; P=0.04, and VFI (0.68±0.18 vs 0.79±0.21; P=0.006 were significantly lower in the stimulated cycles. However, there were no significant differences in the uterine artery PI (P=0.12 and RI (P=0.08 or serum estradiol (P=0.54 and progesterone (P=0.37 levels between natural and stimulated cycles. Conclusion: Peri-implantation endometrial perfusion is significantly lower in clomiphene citrate stimulated

  11. The efficacy of metformin and clomiphene citrate combination compared with clomiphene citrate alone for ovulation induction in infertile patients with PCOS

    Directory of Open Access Journals (Sweden)

    Papa Dasari

    2009-01-01

    Full Text Available Context: Low ovulatory and pregnancy rates with clomiphene citrate (CC in anovulatory polycystic ovarian syndrome (PCOS. Aim: To find out the ovulatory and pregnancy rates in infertile PCOS subjects who receive CC alone and a combination of metformin and CC. Setting and Design: A prospective controlled clinical trial conducted in the outpatient department from August 2003 to August 2005. Materials and Methods: Twenty-four infertile PCOS women received CC alone at incremental doses of 50 mg up to 150 mg for three cycles and then at a dose of 150 mg for another three cycles (control group. The study group (16 PCOS received the same dose of CC along with 1500mg of metformin. Ovulation was monitored by transvaginal sonography up to six cycles or till pregnancy occurred. Statistical Analysis: This was carried out using software SSPS, version 10. Fisher′s exact test was used to calculate the ovulatory rates. Nine subjects of the control group who failed to conceive with CC had opted for CC and metformin and their ovulatory rate was calculated using statistical software, namely SPSS 15.0, Stata 8.0, MedCalc 9.0.1 and Systat 11.0 using Fischer′s exact test. Results: The metformin and clomiphene combination resulted in a significantly higher rate of ovulation ( P = 0.0016. The pregnancy rate was 8% with CC and 24% with metformin and CC. The CC failure group also ovulated at a similar rate as that of the study group. Conclusions: The ovulatory rate and the pregnancy rate with the metformin-CC combination was found to be higher when compared with CC alone. Metformin increased the ovulatory rate in CC failures, also implying increased sensitivity to CC.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Kumahor, Samuel K., E-mail: samuel.kumahor@ufz.de [Department of Soil Physics, Helmholtz Centre for Environmental Research–UFZ, Theodor-Lieser-Strasse 4, 06120 Halle-Saale (Germany); Hron, Pavel, E-mail: pavel.hron@iwr.uni-heidelberg.de [Interdisciplinary Center for Scientific Computing, University of Heidelberg, Im Neuenheimer Feld 368, Raum 422, 69120 Heidelberg (Germany); Metreveli, George, E-mail: metreveli@uni-landau.de [Universität Koblenz-Landau, Institute for Environmental Sciences, Group of Environmental and Soil Chemistry, Fortstr. 7, D-76829 Landau (Germany); Schaumann, Gabriele E., E-mail: schaumann@uni-landau.de [Universität Koblenz-Landau, Institute for Environmental Sciences, Group of Environmental and Soil Chemistry, Fortstr. 7, D-76829 Landau (Germany); Vogel, Hans-Jörg, E-mail: hans-joerg.vogel@ufz.de [Department of Soil Physics, Helmholtz Centre for Environmental Research–UFZ, Theodor-Lieser-Strasse 4, 06120 Halle-Saale (Germany); Institute of Soil Science and Plant Nutrition, Martin-Luther-University Halle-Wittenberg, Von-Seckendorff-Platz 3, 06120 Halle-Saale (Germany)

    2015-12-01

    Chemical factors and physical constraints lead to coupled effects during particle transport in unsaturated porous media. Studies on unsaturated transport as typical for soils are currently scarce. In unsaturated porous media, particle mobility is determined by the existence of an air–water interface in addition to a solid–water interface. To this end, we measured breakthrough curves and retention profiles of citrate-coated Ag nanoparticles in unsaturated sand at two pH values (5 and 9) and three different flow rates corresponding to different water contents with 1 mM KNO{sub 3} as background electrolyte. The classical DLVO theory suggests unfavorable deposition conditions at the air–water and solid–water interfaces. The breakthrough curves indicate modification in curve shapes and retardation of nanoparticles compared to inert solute. Retention profiles show sensitivity to flow rate and pH and this ranged from almost no retention for the highest flow rate at pH = 9 to almost complete retention for the lowest flow rate at pH = 5. Modeling of the breakthrough curves, thus, required coupling two parallel processes: a kinetically controlled attachment process far from equilibrium, responsible for the shape modification, and an equilibrium sorption, responsible for particle retardation. The non-equilibrium process and equilibrium sorption are suggested to relate to the solid–water and air–water interfaces, respectively. This is supported by the DLVO model extended for hydrophobic interactions which suggests reversible attachment, characterized by a secondary minimum (depth 3–5 kT) and a repulsive barrier at the air–water interface. In contrast, the solid–water interface is characterized by a significant repulsive barrier and the absence of a secondary minimum suggesting kinetically controlled and non-equilibrium interaction. This study provides new insights into particle transport in unsaturated porous media and offers a model concept representing the

  17. Dry Process for Manufacturing Hybridized Boron Fiber/Carbon Fiber Thermoplastic Composite Materials from a Solution Coated Precursor

    Science.gov (United States)

    Belvin, Harry L. (Inventor); Cano, Roberto J. (Inventor)

    2003-01-01

    An apparatus for producing a hybrid boron reinforced polymer matrix composite from precursor tape and a linear array of boron fibers. The boron fibers are applied onto the precursor tapes and the precursor tape processed within a processing component having an impregnation bar assembly. After passing through variable-dimension forming nip-rollers, the precursor tape with the boron fibers becomes a hybrid boron reinforced polymer matrix composite. A driving mechanism is used to pulled the precursor tape through the method and a take-up spool is used to collect the formed hybrid boron reinforced polymer matrix composite.

  18. Precursors in photonic crystals - art. no. 618218

    NARCIS (Netherlands)

    Uitham, R.; Hoenders, B. J.; DeLaRue, RM; Viktorovitch, P; Lopez, C; Midrio, M

    2006-01-01

    We derive the Sommerfeld precursor and present the first calculations for the Brillouin precursor that result from the transmission of a pulse through a photonic crystal. The photonic crystal is modelled by a one-dimensional N-layer medium and the pulse is a generic electromagnetic plane wave packet

  19. The Sommerfeld precursor in photonic crystals

    NARCIS (Netherlands)

    Uitham, R; Hoenders, BJ

    2006-01-01

    We calculate the Sommerfeld precursor that results after transmission of a generic electromagnetic plane wave pulse with transverse electric polarization, through a one-dimensional rectangular N-layer photonic crystal with two slabs per layer. The shape of this precursor equals the shape of the

  20. Bioinspired magnetite synthesis via solid precursor phases

    NARCIS (Netherlands)

    Lenders, J.J.M.; Mirabello, G.; Sommerdijk, N.A.J.M.

    2016-01-01

    Living organisms often exploit solid but poorly ordered mineral phases as precursors in the biomineralization of their inorganic body parts. Generally speaking, such precursor-based approaches allow the organisms-without the need of high supersaturation levels-to accumulate significant quantities of

  1. Boron nitride ceramics from molecular precursors: synthesis, properties and applications.

    Science.gov (United States)

    Bernard, Samuel; Salameh, Chrystelle; Miele, Philippe

    2016-01-21

    Hexagonal boron nitride (h-BN) attracts considerable interest because its structure is similar to that of carbon graphite while it displays different properties which are of interest for environmental and green technologies. The polar nature of the B-N bond in sp(2)-bonded BN makes it a wide band gap insulator with different chemistry on its surface and particular physical and chemical properties such as a high thermal conductivity, a high temperature stability, a high resistance to corrosion and oxidation and a strong UV emission. It is chemically inert and nontoxic and has good environmental compatibility. h-BN also has enhanced physisorption properties due to the dipolar fields near its surface. Such properties are closely dependent on the processing method. Bottom-up approaches consist of transforming molecular precursors into non-oxide ceramics with retention of the structural units inherent to the precursor molecule. The purpose of the present review is to give an up-to-date overview on the most recent achievements in the preparation of h-BN from borazine-based molecular single-source precursors including borazine and 2,4,6-trichloroborazine through both vapor phase syntheses and methods in the liquid/solid state involving polymeric intermediates, called the Polymer-Derived Ceramics (PDCs) route. In particular, the effect of the chemistry, composition and architecture of the borazine-based precursors and derived polymers on the shaping ability as well as the properties of h-BN is particularly highlighted.

  2. The interrelationships of mathematical precursors in kindergarten.

    Science.gov (United States)

    Cirino, Paul T

    2011-04-01

    This study evaluated the interrelations among cognitive precursors across quantitative, linguistic, and spatial attention domains that have been implicated for math achievement in young children. The dimensionality of the quantity precursors was evaluated in 286 kindergarteners via latent variable techniques, and the contribution of precursors from each domain was established for small sums addition. Results showed a five-factor structure for the quantity precursors, with the major distinction being between nonsymbolic and symbolic tasks. The overall model demonstrated good fit and strong predictive power (R(2)=55%) for addition number combinations. Linguistic and spatial attention domains showed indirect relationships with outcomes, with their effects mediated by symbolic quantity measures. These results have implications for the measurement of mathematical precursors and yield promise for predicting future math performance. Copyright © 2010 Elsevier Inc. All rights reserved.

  3. Citrate mediated synthesis and tuning of luminescence in Eu3+ incorporated Gd2O3 nanophosphors

    Science.gov (United States)

    Abhilash Kumar, R. G.; Gopchandran, K. G.

    2015-02-01

    Gd1.9Eu0.1O3 nanophosphors were prepared successfully by a large-scale facile solution based citrate-metal complex controlled combustion method and was systematically studied by varying the citric acid to metal cation ratio. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), photoluminescence (PL) measurements and radiative properties were done to evaluate the crystal structure, phase formation, phase composition, surface morphology, radiative and luminescent properties of the prepared nanophosphors. Photoluminescent emission intensity of the samples can be correlated with the amount of citric acid, improved crystallinity, uniform morphology, particle size, reduced defects, and proper diffusion of Eu3+ in to the crystal structure of Gd2O3. Higher asymmetricity results in intense red emission (612 nm) due to 5D0-7F2 forced electric dipole transition and found that photoluminescence intensity is highest for the sample prepared with citric acid to metal cation ratio of 2:1. The existence of strong red emission from Gd1.9Eu0.1O3 nanophosphor corresponding to 5D0-7F2 transition (612 nm) of Eu3+ under UV light excitation make it a promising candidate for applications in bio assays, magnetic resonance imaging, deep uv LED's, solid state lighting, fluorescent lamps and flat panel displays.

  4. Subcutaneous injection of thallium-201 chloride and gallium-67 citrate at acupuncture point K-3

    International Nuclear Information System (INIS)

    Johg, Shiang-Bin; Wu, Chung-Chieng; Chen, Ming-Feng; Wu, Sheng-Nan

    1992-01-01

    Subcutaneous (SC) injection of 99m Tc pertechnetate ( 99m Tc) at acupuncture points K-3 is a new method of lower-limb radionuclide venography. To investigate the mechanism of absorption of 99m Tc from SC injected sites into vascular system, various radioisotopes such as 201 Tl chloride ( 201 Tl) and 67 Ga citrate ( 67 Ga) were SC injected at K-3 points in animal and human-beings experiments. It was found that 99m Tc and 201 Tl were absorbed rapidly from K-3 points through venous system and into whole body soft tissue. However, 67 Ga with a larger effective ionic radius than 201 Tl was not absorbed throughout the observation of 5 minutes. Furthermore, intravenous administration of digitalis, a Na + -K + pump blocker, did not inhibit the absorption of 99m Tc and 201 Tl after SC injection at K-3 points. These results suggest that absorption of radionuclides on SC injection at K-3 points is mainly through the passive pathway of diffusion rather than the active transport, and the effective ionic radius may be a major factor influencing the absorption rate of the radionuclides. (author)

  5. Thallium Labeled Citrate-Coated Prussian Blue Nanoparticles as Potential Imaging Agent

    Directory of Open Access Journals (Sweden)

    Krisztián Szigeti

    2018-01-01

    Full Text Available Background. The aim of this study was to develop and characterize a nanoparticle-based image-contrast platform which is biocompatible, chemically stable, and accessible for radiolabeling with 201Tl. We explored whether this nanoparticle enhanced the T1 signal which might make it an MRI contrast agent as well. Methods. The physical properties of citrate-coated Prussian blue nanoparticles (PBNPs (iron(II;iron(III;octadecacyanide doped with 201Tl isotope were characterized with atomic force microscopy, dynamic light scattering, and zeta potential measurement. PBNP biodistribution was determined by using SPECT and MRI following intravenous administration into C57BL6 mice. Activity concentrations (MBq/cm3 were calculated from the SPECT scans for each dedicated volume of interest (VOI of liver, kidneys, salivary glands, heart, lungs, and brain. Results. PBNP accumulation peaked at 2 hours after injection predominantly in the kidneys and the liver followed by a gradual decrease in activity in later time points. Conclusion. We synthetized, characterized, and radiolabeled a Prussian blue-based nanoparticle platform for contrast material applications. Its in vivo radiochemical stability and biodistribution open up the way for further diagnostic applications.

  6. 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.

  7. 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

  8. Nitrate Protects Cucumber Plants Against Fusarium oxysporum by Regulating Citrate Exudation.

    Science.gov (United States)

    Wang, Min; Sun, Yuming; Gu, Zechen; Wang, Ruirui; Sun, Guomei; Zhu, Chen; Guo, Shiwei; Shen, Qirong

    2016-09-01

    Fusarium wilt causes severe yield losses in cash crops. Nitrogen plays a critical role in the management of plant disease; however, the regulating mechanism is poorly understood. Using biochemical, physiological, bioinformatic and transcriptome approaches, we analyzed how nitrogen forms regulate the interactions between cucumber plants and Fusarium oxysporum f. sp. cucumerinum (FOC). Nitrate significantly suppressed Fusarium wilt compared with ammonium in both pot and hydroponic experiments. Fewer FOC colonized the roots and stems under nitrate compared with ammonium supply. Cucumber grown with nitrate accumulated less fusaric acid (FA) after FOC infection and exhibited increased tolerance to chemical FA by decreasing FA absorption and transportation in shoots. A lower citrate concentration was observed in nitrate-grown cucumbers, which was associated with lower MATE (multidrug and toxin compound extrusion) family gene and citrate synthase (CS) gene expression, as well as lower CS activity. Citrate enhanced FOC spore germination and infection, and increased disease incidence and the FOC population in ammonium-treated plants. Our study provides evidence that nitrate protects cucumber plants against F. oxysporum by decreasing root citrate exudation and FOC infection. Citrate exudation is essential for regulating disease development of Fusarium wilt in cucumber plants. © The Author 2016. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  9. Bio-inspired citrate functionalized apatite coating on rapid prototyped titanium scaffold

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Peng [National engineering research center for tissue restoration and reconstruction, South China University of Technology, Guangzhou 510641 (China); Lu, Fang [School of Chinese Materia Medica, Guangzhou University of Chinese Medicine, Guangzhou 510006 (China); Zhu, Wenjun [Department of Prosthodontics, Guanghua School of Stomatology, Guang Dong Key Laboratory of Stomatology, Sun Yat-sen University, Guangzhou 510055 (China); Wang, Di [National engineering research center for tissue restoration and reconstruction, South China University of Technology, Guangzhou 510641 (China); Zhu, Xiaojing [Department of Prosthodontics, Guanghua School of Stomatology, Guang Dong Key Laboratory of Stomatology, Sun Yat-sen University, Guangzhou 510055 (China); Tan, Guoxin, E-mail: tanguoxin@126.com [Institute of Chemical Engineering and Light Industry, Guangdong University of Technology, Guangzhou 510006 (China); Wang, Xiaolan [National engineering research center for tissue restoration and reconstruction, South China University of Technology, Guangzhou 510641 (China); Zhang, Yu; Li, Lihua [General Hospital of Guangzhou Military Command of PLA, Guangzhou 510010 (China); Ning, Chengyun, E-mail: imcyning@scut.edu.cn [National engineering research center for tissue restoration and reconstruction, South China University of Technology, Guangzhou 510641 (China)

    2014-09-15

    Highlights: • Designed and reproducible porous titanium scaffolds were produced. • Hydrophilic nanoporous film was built on scaffold. • Apatite coating was deposited on scaffold under the modulation of citrate ions. • Citrate ions could affect CO{sub 3}{sup 2−} incorporation in apatite coatings. - Abstract: Scaffold functionalized with appropriate osteogenic coatings can significantly improve implant-bone response. In this study, with designed model and optimized manufacture parameters, reproducible and precise titanium scaffolds were produced. Reconstructed three-dimensional image and sectional structure of the scaffold were examined by micro-computed tomography and relative software. Alkali treatment was carried out on these manufactured porous scaffolds to produce nanoporous hydrophilic film. After 6 days deposition in simulated body fluid (SBF) containing sodium citrate (SC-SBF), plate-like amorphous calcium phosphate (ACP) coating was deposited on scaffold surface. Ultrasonication tests qualitatively indicated an enhanced adhesion force of apatite coatings deposited in SC-SBF compared to that deposited in SBF. And the effect of citrate ions on the CO{sub 3}{sup 2−} incorporation rate in apatite coating was quantitatively examined by bending vibration of CO{sub 3}{sup 2−} at ∼874 cm{sup −1}. Results indicated the highest carbonate content was obtained at the citrate ion concentration of 6 × 10{sup −5} mol/L in SC-SBF. These three-dimensional porous titanium-apatite hybrid scaffolds are expected to find application in bone tissue regeneration.

  10. Rapid visual detection of quaternary ammonium surfactants using citrate-capped silver nanoparticles (Ag NPs) based on hydrophobic effect.

    Science.gov (United States)

    Zheng, Li-Qing; Yu, Xiao-Dong; Xu, Jing-Juan; Chen, Hong-Yuan

    2014-01-01

    In this work, a rapid, sensitive and low-cost colorimetric method for detection of quaternary ammonium surfactants using citrate-capped silver nanoparticles (Ag NPs) was developed. The quaternary ammonium surfactants induce the aggregation of Ag NPs through the hydrophobic effect, which is a novel aggregation mechanism of Ag NPs. The addition of cationic surfactant results in color change of Ag NPs solution from yellow to red and finally to colorless, which is due to the broadening of the surface plasmon band. The color change was monitored using a UV-vis spectrophotometer. The LOD of different cationic surfactants was in the range of 0.5-5 µM. More importantly, this detection method was successfully utilized to the disinfectant residual sample. Crown Copyright © 2013 Published by Elsevier B.V. All rights reserved.

  11. Synthesis of nanoparticles of magnetite by sol-gel and precipitation methods: study of chemical composition and structure

    International Nuclear Information System (INIS)

    Picasso, Gino; Vega, Jaime; Uzuriaga, Rosario; Ruiz, Gean Pieer

    2012-01-01

    In this work, nanoparticles based on magnetite have been prepared by sol-gel and precipitation methods. In the first case two variants have been applied: by growing of sol starting from nitrate precursor and ethylene glycol as solvent and to control the reduction process and force hydrolysis and steric control prepared from ferrum sulfate precursor and sodium citrate. In the second case the starting material was sulfate precursor, ammonium hydroxide as precipitaing agent and ethylene glycol as surfactant. The samples have been characterized by X-ray diffraction technique (XRD), adsorption-desorption of N 2 (BET equation model) and Moessbauer spectroscopy. XRD patterns of all samples showed typical peaks of magnetite which were detected in the following positions: 30,06 o , 35,42 o , 62,55 o . Average specific surface quantified by BET method was ranging from 40 to 50 m 2 /g with isotherm type IV corresponding to mesoporous surface. Moessbauer spectra of sample prepared from sol-gel (gel growing) carried out at home temperature detected the presence of 2 sextets consisting in 2 type of sites: first one due to octahedral positions (Fe 2+ , Fe 3+ ) and the second one due to tetrahedral positions (Fe 3+ ). Grain size of magnetite samples, evaluated by Scherrer equation and specific surface area, was ranging from 2 to 20 nm. (author).

  12. Contributions of citrate in redox potential maintenance and ATP production: metabolic pathways and their regulation in Lactobacillus panis PM1.

    Science.gov (United States)

    Kang, Tae Sun; Korber, Darren R; Tanaka, Takuji

    2013-10-01

    Lactobacillus panis PM1 belongs to the group III heterofermentative lactobacilli and can utilize various NADH-reoxidizing routes (e.g., citrate, glycerol, and oxygen) according to environmental conditions. In this study, we investigated the ability of L. panis PM1 to produce succinate, acetate, and lactate via citrate utilization. Possible pathways, as well as regulation, for citrate metabolism were examined on the basis of the genome sequence data and metabolic profiles of L. panis PM1. The presence of citrate led to the up-regulation, at the transcriptional level, of the genes encoding for citrate lyase, malate dehydrogenase, and malic enzyme of the citrate pathways by 10- to 120-fold. The transcriptional regulator of the dha operon coding for glycerol dehydratase of L. panis PM1 repressed the expression of the citrate lyase gene (10-fold). Metabolite analyses indicated that the transcriptional enhancement by citrate stimulated succinate yield. Citrate metabolism contributed to energy production by providing a major alternate pathway for NAD(+) regeneration and allowed acetyl phosphate to yield acetate/ATP instead of ethanol/NAD(+). Additionally, a branching pathway from oxaloacetate to pyruvate increased the pool of lactate, which was then used to produce ATP during stationary phase. However, the redirection of NADH-to-citrate utilization resulted in stress caused by end-products (i.e., succinate and acetate). This stress reduced succinate production by up to 50 % but did not cause significant changes at transcriptional level. Overall, citrate utilization was beneficial for the growth of L. panis PM1 by providing a NAD(+) regeneration route and producing extra ATP.

  13. Women taking the “blue pill” (sildenafil citrate: such a big deal?

    Directory of Open Access Journals (Sweden)

    Lo Monte G

    2014-11-01

    Full Text Available Giuseppe Lo Monte, Angela Graziano, Isabella Piva, Roberto Marci Department of Morphology, Surgery, and Experimental Medicine, University of Ferrara, Ferrara, Italy Abstract: For years, phosphodiesterase type 5 inhibitors have been used for the treatment of erectile dysfunctions. Due to the similarities between male and female sexual response, several studies have assessed the effects of sildenafil citrate (Viagra® in women affected by female sexual arousal disorder. The results are still conflicting and the drug is not devoid of adverse effects. Furthermore, female sexual arousal disorder is a heterogeneous condition whose underlying causes are difficult to diagnose and appropriate treatment requires a thorough sexual, psychological, and medical history along with specialist consultations. The clinician should pursue a global approach to the patient with sexual difficulties, while non-hormonal treatment such as phosphodiesterase type 5 inhibitors (ie, sildenafil citrate should be kept as the last option. Keywords: phosphodiesterase type 5 inhibitors, female sexual arousal disorder (FSAD, sildenafil citrate

  14. A fundamental study on brain scanning with sup(99m)Tc-citrate

    International Nuclear Information System (INIS)

    Ishii, Katsumi; Kobayashi, Takeshi; Yamada, Nobuaki; Horiike, Shigeharu; Nakazawa, Keiji

    1978-01-01

    We examined the sup(99m)Tc-citrate obtained by labelling citrate with sup(99m)Tc-pertechnetate using Solcocitran Kit. For our fundamental study--we measured the ratio of labelling by means of paper chromatography. By picking out each organs of each rats we also measured the velocity at which radiopharmaceuticals disappeared in each of their organs, and the distribution of radio-pharmaceuticals in their organs. For our clinical study--we performed brain scanning on 47 patients. The following are the results; Citrate was labelled as much as 99 - 95% into sup(99m)Tc-pertechnetate. The velocity of disappearance in each organ of the rats was quicker than in the case of sup(99m)TcO 4 - . Accumulation in the choroid plexus and salivary gland was not obserbed despite the fact that we did not use KClo 4 , and images of brain tumor were obtainable to a high degree. (author)

  15. Human METTL12 is a mitochondrial methyltransferase that modifies citrate synthase.

    Science.gov (United States)

    Rhein, Virginie F; Carroll, Joe; Ding, Shujing; Fearnley, Ian M; Walker, John E

    2017-06-01

    The protein methylome in mammalian mitochondria has been little studied until recently. Here, we describe that lysine-368 of human citrate synthase is methylated and that the modifying enzyme, localized in the mitochondrial matrix, is methyltransferase-like protein 12 (METTL12), a member of the family of 7β-strand methyltransferases. Lysine-368 is near the active site of citrate synthase, but removal of methylation has no effect on its activity. In mitochondria, it is possible that some or all of the enzymes of the citric acid cycle, including citrate synthase, are organized in metabolons to facilitate the channelling of substrates between participating enzymes. Thus, possible roles for the methylation of Lys-368 are in controlling substrate channelling itself, or in influencing protein-protein interactions in the metabolon. © 2017 The Authors FEBS Letters published by John Wiley & Sons Ltd on behalf of Federation of European Biochemical Societies.

  16. Is magnesium citrate treatment effective on pain, clinical parameters and functional status in patients with fibromyalgia?

    Science.gov (United States)

    Bagis, Selda; Karabiber, Mehmet; As, Ismet; Tamer, Lülüfer; Erdogan, Canan; Atalay, Ayçe

    2013-01-01

    The aims of this study were to investigate the relationship between magnesium levels and fibromyalgia symptoms and to determine the effect of magnesium citrate treatment on these symptoms. Sixty premenopausal women diagnosed with fibromyalgia according to the ACR criteria and 20 healthy women whose age and weight matched the premenopausal women were evaluated. Pain intensity, pain threshold, the number of tender points, the tender point index, the fibromyalgia impact questionnaire (FIQ), the Beck depression and Beck anxiety scores and patient symptoms were evaluated in all the women. Serum and erythrocyte magnesium levels were also measured. The patients were divided into three groups. The magnesium citrate (300 mg/day) was given to the first group (n = 20), amitriptyline (10 mg/day) was given to the second group (n = 20), and magnesium citrate (300 mg/day) + amitriptyline (10 mg/day) treatment was given to the third group (n = 20). All parameters were reevaluated after the 8 weeks of treatment. The serum and erythrocyte magnesium levels were significantly lower in patients with fibromyalgia than in the controls. Also there was a negative correlation between the magnesium levels and fibromyalgia symptoms. The number of tender points, tender point index, FIQ and Beck depression scores decreased significantly with the magnesium citrate treatment. The combined amitriptyline + magnesium citrate treatment proved effective on all parameters except numbness. Low magnesium levels in the erythrocyte might be an etiologic factor on fibromyalgia symptoms. The magnesium citrate treatment was only effective tender points and the intensity of fibromyalgia. However, it was effective on all parameters when used in combination with amitriptyline.

  17. 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.

  18. Abnormal splenic uptake of gallium-67 citrate in a case of infectious mononucleosis

    International Nuclear Information System (INIS)

    Campeau, R.J.; LaCorte, W.S.

    1985-01-01

    A case of fever of undetermined origin (FUO) demonstrated abnormal intense concentration of Ga-67 citrate in the spleen. Initial workup demonstrated two negative mono spot tests for infectious mononucleosis (IM) but, on hospital day 2, a repeat mono test was positive. The diagnosis was subsequently confirmed by rising heterophilic antibody titers. Six weeks after hospital discharge, repeat Ga-67 citrate imaging demonstrated absence of abnormal splenic activity. To our knowledge, this phenomenon has not been previously described in IM. In the appropriate clinical setting, intense splenic uptake of Ga-67 should alert the clinician to include the possibility of IM in the differential diagnosis

  19. Citrate effects on amorphous calcium carbonate (ACC) structure, stability, and crystallization

    DEFF Research Database (Denmark)

    Tobler, Dominique Jeanette; Rodriguez Blanco, Juan Diego; Dideriksen, Knud

    2015-01-01

    Understanding the role of citrate in the crystallization kinetics of amorphous calcium carbonate (ACC) is essential to explain the formation mechanisms, stabilities, surface properties, and morphologies of CaCO3 biominerals. It also contributes to deeper insight into fluid-mineral inte......Understanding the role of citrate in the crystallization kinetics of amorphous calcium carbonate (ACC) is essential to explain the formation mechanisms, stabilities, surface properties, and morphologies of CaCO3 biominerals. It also contributes to deeper insight into fluid...

  20. Diffuse abdominal uptake of Ga-67 citrate in a patient with hypoproteinemia

    International Nuclear Information System (INIS)

    Kim, E.E.; Gobuty, A.; Gutierrez, C.

    1983-01-01

    A 3-wk-old male, with abdominal distention and severe hypoproteinemia from poor nutrition, underwent a study that showed a persistent diffuse abdominal uptake of Ga-67 citrate, indicating pyogenic or tuberculous peritonitis. However, there were no corresponding clinical or laboratory findings. After a 1-wk course of hyperalimentation with albumin, furosemide, and protein, repeat radiographs showed reduction in bowel gas. It is suggested that hypoproteinemia should be considered as a possibility in the differential diagnosis when there is diffuse abdominal uptake of Ga-67 citrate, with careful clinical correlation. Possible mechanism of Ga-67 uptake in the peritoneal cavity is suggested

  1. Increased tumor uptake of 67Ga citrate following a course of picibanil (NSC-B116209)

    International Nuclear Information System (INIS)

    Okuyama, Shinichi; Matsuzawa, Taiju; Mishina, Hitoshi.

    1979-01-01

    Exposure to exponential dose schedules of OK-432, penicillin-inactivated preparation of streptococcus hemolyticus (NSC-B116209), resulted in an increased retention of 67 Ga citrate. Its uptake in footpad tumors of AH 109A was also increased. The results may suggest that pretreatment with OK-432 would increase tumor uptake of 67 Ga citrate and help scintigraphic delineation of malignancies in man. It may probably augment tumor concentration of anticancer chemotherapeutics, too. Thus, the tumor affinitive property of OK-432 can be taken advantage of in anticancer strategy as well as cancer detection by 67 Ga scanning. (author)

  2. Removal of radioactive cesium from soil by ammonium citrate solution and ionic liquid

    International Nuclear Information System (INIS)

    Ishiwata, Shunji; Kitakouji, Manabu; Taga, Atsushi; Ogata, Fumihiko; Ouchi, Hidekazu; Yamanishi, Hirokuni; Inagaki, Masayo

    2015-01-01

    Radioactive cesium has strongly bound soil as time proceeded, which could not be cleaved in mild condition. We have found that serial treatment of ammonium citrate solution and ionic liquid removed radioactive cesium from soil effectively. The sequence of the treatment is crucial, since inverse serial treatment or mixture of two kinds of solution did not show such an effect, which suggested that ammonium citrate unlocked trapped cesium in soil and ionic liquid solved it. We also found that repeating serial treatment and prolonged treatment time additively removed cesium from soil. (author)

  3. Citrate, a Ubiquitous Key Metabolite with Regulatory Function in the CNS

    DEFF Research Database (Denmark)

    Westergaard, Niels; Waagepetersen, Helle S; Belhage, Bo

    2017-01-01

    Citrate is key constituent of the tricarboxylic acid (TCA) cycle, serves as substrate for fatty acid and sterol biosynthesis, and functions as a key regulator of intermediary energy metabolism. Ursula Sonnewald had initiated studies using for the first time both proton- and 13C-NMR to investigate...... metabolic processes in cultured neurons and astrocytes resulting in the important observation that citrate was specifically synthesized in and released from astrocytes in large amounts which is in keeping with the high concentration found in the CSF. The aim of this review is to highlight the possible roles...

  4. Citrate metabolism in blood transfusions and its relationship due to metabolic alkalosis and respiratory acidosis.

    Science.gov (United States)

    Li, Kai; Xu, Yuan

    2015-01-01

    Metabolic alkalosis commonly results from excessive hydrochloric acid (HCl), potassium (K(+)) and water (H2O) loss from the stomach or through the urine. The plasma anion gap increases in non-hypoproteinemic metabolic alkalosis due to an increased negative charge equivalent on albumin and the free ionized calcium (Ca(++)) content of plasma decreases. The mean citrate load in all patients was 8740±7027 mg from 6937±6603 mL of transfused blood products. The citrate load was significantly higher in patients with alkalosis (9164±4870 vs. 7809±3967, P alkalosis + respiratory acidosis and electrolyte imbalance may develop, blood transfusions may result in certain complications.

  5. 77 FR 72323 - Citric Acid and Certain Citrate Salts From the People's Republic of China: Final Results of...

    Science.gov (United States)

    2012-12-05

    ... DEPARTMENT OF COMMERCE International Trade Administration [C-570-938] Citric Acid and Certain... countervailing duty (CVD) order on citric acid and certain citrate salts from the People's Republic of China for... results of this review.\\1\\ \\1\\ See Citric Acid and Certain Citrate Salts from the People's Republic of...

  6. 76 FR 47146 - Citric Acid and Certain Citrate Salts From the People's Republic of China: Extension of Time...

    Science.gov (United States)

    2011-08-04

    ... DEPARTMENT OF COMMERCE International Trade Administration [A-570-937] Citric Acid and Certain... review of the antidumping duty order on citric acid and certain citrate salts (``citric acid'') from the... of citric acid from the PRC. See Citric Acid and Certain Citrate Salts From the People's Republic of...

  7. 76 FR 82275 - Citric Acid and Certain Citrate Salts From the People's Republic of China: Extension of Time...

    Science.gov (United States)

    2011-12-30

    ... DEPARTMENT OF COMMERCE International Trade Administration [C-570-938] Citric Acid and Certain...) published in the Federal Register the countervailing duty order on citric acid and certain citrate salts... Affirmative Countervailing Duty Determinations: Citric Acid and Certain Citrate Salts, 74 FR 25705 (May 29...

  8. 78 FR 54625 - Citric Acid and Certain Citrate Salts From the People's Republic of China: Notice of Partial...

    Science.gov (United States)

    2013-09-05

    ... DEPARTMENT OF COMMERCE International Trade Administration [C-570-938] Citric Acid and Certain Citrate Salts From the People's Republic of China: Notice of Partial Rescission of Countervailing Duty... of the countervailing duty (CVD) order on citric acid and certain citrate salts from the People's...

  9. 77 FR 74171 - Citric Acid and Certain Citrate Salts From the People's Republic of China: Final Results of...

    Science.gov (United States)

    2012-12-13

    ... DEPARTMENT OF COMMERCE International Trade Administration [A-570-937] Citric Acid and Certain... review of the antidumping duty order on citric acid and certain citrate salts from the People's Republic..., regarding ``Second Antidumping Administrative Review of Citric Acid and Certain Citrate Salts from the...

  10. 76 FR 2648 - Citric Acid and Certain Citrate Salts From People's Republic of China: Extension of Time Limit...

    Science.gov (United States)

    2011-01-14

    ... DEPARTMENT OF COMMERCE International Trade Administration [C-570-938] Citric Acid and Certain Citrate Salts From People's Republic of China: Extension of Time Limit for the Preliminary Results of the... duty order on citric acid and certain citrate salts from the People's Republic of China, covering the...

  11. 77 FR 56188 - Citric Acid and Certain Citrate Salts from the People's Republic of China: Notice of Rescission...

    Science.gov (United States)

    2012-09-12

    ... DEPARTMENT OF COMMERCE International Trade Administration [C-570-938] Citric Acid and Certain... (CVD) order on citric acid and certain citrate salts from the People's Republic of China.\\1\\ On [[Page...\\ See Citric Acid and Certain Citrate Salts from the People's Republic of China: Intent to Rescind...

  12. A light-up fluorescent probe for citrate detection based on bispyridinum amides with aggregation-induced emission feature.

    Science.gov (United States)

    Liu, Chenchen; Hang, Yandi; Jiang, Tao; Yang, Ji; Zhang, Xiao; Hua, Jianli

    2018-02-01

    Citrate is an important intermediate in the citric acid cycle, a vital metabolic pathway for animals, plants and bacteria. It is of great significance to detect its levels in human beings because several diseases may cause the abnormal of citrate. In this paper, a new turn-on fluorescent sensor (TPE-Py) using the classic tetraphenylethylene (TPE) as the aggregation-induced emission (AIE) fluorophore and bipyridinium-based amides as the recognition receptor has been synthesized for the detection of citrate. The probe exhibits good selectivity and sensitivity to citrate with a relatively low detection limit (1.0 × 10 -7 M). The enhancement of the fluorescence is relevant with the AIE property based on the complexation of TPE-Py with citrate caused by the hydrogen bonding and electrostatic interactions between the bipyridinium diamides and citrate, which has been proved by 1 H NMR and mass spectra titration, scanning electronic microscope and dynamic light scattering analyses. More importantly, the quantification of citrate in artificial urine may develop TPE-Py fluorometric probe for the citrate detection in real biosystems. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. The safety and efficacy of ranitidine bismuth citrate in combination with antibiotics for the eradication of Helicobacter pylori

    NARCIS (Netherlands)

    Wyeth, J. W.; Pounder, R. E.; Duggan, A. E.; O'Morain, C. A.; Schaufelberger, H. D.; de Koster, E. H.; Rauws, E. A.; Bardhan, K. D.; Gilvarry, J.; Buckley, M. J.; Gummett, P. A.; Logan, R. P.

    1996-01-01

    Ranitidine bismuth citrate is a novel salt of ranitidine and a bismuth citrate complex. It has intrinsic antisecretory and anti-Helicobacter pylori activity, but monotherapy rarely eradicates H. pylori infection in man. A pilot study to investigate rates of H. pylori eradication achieved by

  14. Does adding metformin to clomifene citrate lead to higher pregnancy rates in a subset of women with polycystic ovary syndrome?

    NARCIS (Netherlands)

    Moll, E.; Korevaar, J. C.; Bossuyt, P. M. M.; van der Veen, F.

    2008-01-01

    BACKGROUND: An RCT among newly diagnosed, therapy naive women with polycystic ovary syndrome (PCOS) showed no significant differences in ovulation rate, ongoing pregnancy rate or spontaneous abortion rate in favour of clomifene citrate plus metformin compared with clomifene citrate. We wanted to

  15. Crystallization and magnetic characterizations of DyIG and HoIG nanopowders fabricated using citrate sol-gel

    Directory of Open Access Journals (Sweden)

    Dao Thi Thuy Nguyet

    2016-06-01

    Full Text Available Dy and Ho iron garnets in form of nanoparticles were synthesized by citrate sol-gel method. Phase formation, lattice constant and average crystallite sizes of the samples were determined via XRD measurements. Morphology and particle size distribution were studied by TEM and chemical composition was checked by EDX. Magnetic measurements in temperature range 5–600 K and in the maximum applied field of 50 kOe were carried out by using SQUID and VSM. Their magnetic parameters, including Curie temperature, magnetization compensation temperature, spontaneous magnetization, high-field susceptibility, magnetic coercivity were discussed in the framework of three interacting magnetic sublattices, magnetocrystalline anisotropy, core-shell model and compared to those of the bulk materials. Based on these analyses further evaluation on the crystallinity and homogeneity of the samples has been made.

  16. Primary double contrast study of the colon with citrate-sorbitol-barium suspension in the diagnosis of chronic colitis

    International Nuclear Information System (INIS)

    Sidorov, V.S.

    1991-01-01

    X-ray investigation of the colon was conducted in 292 patients with clinically diagnosed chronic colitis: standard 3-phase irrigoscopy-in 189 patients and a primary double contrast study of the colon with citrate-sorbitol-barium suspenzion - in 103. Basing on X-ray and morphological findings, the diagnosis was confirmed in 128 patients of the 1st group (68.2 %) and in 89 patients of the 2nd group (86 %). The primary double contrast study of the colon was found more effective as it permitted the detection of elements of the mucosal microcontours: transversal strips, not coinciding with haustration, focal granularity, diffuse granularity, small barium suspension depots or niches, nodular granularity. It permitted the recommendation of the method for a wide clinical use

  17. Synthesis of Nanocrystalline RuO2(60%)-SnO2(40%)Powders by Amorphous Citrate Route

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Nanometer RuO2-SnO2was synthesized by the citrate-gel method using RuCl3, SnCl4 as cation sources, citric acid as complexing agent and anhydrous ethanol as solvent. The structures of the derived powders were characterized by thermogravimetric and differential thermal analysis, X-ray diffraction, transmission electron microscope, and Brunauer-Emmett-Teller surface area measurement. The pure, fine and amorphous powders was obtained at 160℃. The materials calcined at above 400 ℃ were composed of rutile-type oxide phases having particle sizes of fairly narrow distribution and good thermal resistant properties. By adding SnO2 to RUO2, the Ru metallic phase can be effectively controlled under a traditional temperature of preparation for dimensional stable anode.

  18. Pulmonary scintigraphy by citrate of Ga67 for HIV(+) patients or AIDS. Scintigraphie pulmonaire au citrate de Ga67 chez des patients VIH(+) ou sida

    Energy Technology Data Exchange (ETDEWEB)

    Daumal, J.; Pena, C.; Mata, F.; Paternostro, C.; Penafiel, A. (Hopital Son Dureta, Palma de Mallorca (Spain))

    1993-04-01

    Pulmonary scintigraphy with citrate of gallium 67 is useful when combined with a thorax radiography to establish the presence of an infection. When the two examinations are negative we can conclude there is no infection, but if the radiography is positive with a scintiscanning negative the most possible diagnosis is tuberculosis. If the scintiscanning is positive with a diffuse model we can envisage a pneumonia by Pneumocystis Carinii and if the model is ganglionic we can think to tuberculosis. 4 tabs.

  19. Antitumor effect of free rhodium (II) citrate and rhodium (II) citrate-loaded maghemite nanoparticles on mice bearing breast cancer: a systemic toxicity assay.

    Science.gov (United States)

    Peixoto, Raphael Cândido Apolinário; Miranda-Vilela, Ana Luisa; de Souza Filho, José; Carneiro, Marcella Lemos' Brettas; Oliveira, Ricardo G S; da Silva, Matheus Oliveira; de Souza, Aparecido R; Báo, Sônia Nair

    2015-05-01

    Breast cancer is one of the most prevalent cancer types among women. The use of magnetic fluids for specific delivery of drugs represents an attractive platform for chemotherapy. In our previous studies, it was demonstrated that maghemite nanoparticles coated with rhodium (II) citrate (Magh-Rh2Cit) induced in vitro cytotoxicity and in vivo antitumor activity, followed by intratumoral administration in breast carcinoma cells. In this study, our aim was to follow intravenous treatment to evaluate the systemic antitumor activity and toxicity induced by these formulations in Balb/c mice bearing orthotopic 4T1 breast carcinoma. Female Balb/c mice were evaluated with regard to toxicity of intravenous treatments through analyses of hemogram, serum levels of alanine aminotransferase, iron, and creatinine and liver, kidney, and lung histology. The antitumor activity of rhodium (II) citrate (Rh2Cit), Magh-Rh2Cit, and maghemite nanoparticles coated with citrate (Magh-Cit), used as control, was evaluated by tumor volume reduction, histology, and morphometric analysis. Magh-Rh2Cit and Magh-Cit promoted a significant decrease in tumor area, and no experimental groups presented hematotoxic effects or increased levels of serum ALT and creatinine. This observation was corroborated by the histopathological examination of the liver and kidney of mice. Furthermore, the presence of nanoparticles was verified in lung tissue with no morphological changes, supporting the idea that our nanoformulations did not induce toxicity effects. No studies about the systemic action of rhodium (II) citrate-loaded maghemite nanoparticles have been carried out, making this report a suitable starting point for exploring the therapeutic potential of these compounds in treating breast cancer.

  20. Biochemical Removal of HAP Precursors From Coal

    International Nuclear Information System (INIS)

    Olson, G.; Tucker, L.; Richards, J.

    1997-07-01

    This project addresses DOE's interest in advanced concepts for controlling emissions of air toxics from coal-fired utility boilers. We are determining the feasibility of developing a biochemical process for the precombustion removal of substantial percentages of 13 inorganic hazardous air pollutant (HAP) precursors from coal. These HAP precursors are Sb, As, Be, Cd, Cr, Cl, Co, F, Pb, Hg, Mn, Ni, and Se. Although rapid physical coal cleaning is done routinely in preparation plants, biochemical processes for removal of HAP precursors from coal potentially offer advantages of deeper cleaning, more specificity, and less coal loss. Compared to chemical processes for coal cleaning, biochemical processes potentially offer lower costs and milder process conditions. Pyrite oxidizing bacteria, most notably Thiobacillusferrooxidans, are being evaluated in this project for their ability to remove HAP precursors from U.S. coals

  1. Progress in molecular precursors for electronic materials

    Energy Technology Data Exchange (ETDEWEB)

    Buhro, W.E. [Washington Univ., St. Louis, MO (United States)

    1996-09-01

    Molecular-precursor chemistry provides an essential underpinning to all electronic-materials technologies, including photovoltaics and related areas of direct interest to the DOE. Materials synthesis and processing is a rapidly developing field in which advances in molecular precursors are playing a major role. This article surveys selected recent research examples that define the exciting current directions in molecular-precursor science. These directions include growth of increasingly complex structures and stoichiometries, surface-selective growth, kinetic growth of metastable materials, growth of size-controlled quantum dots and quantum-dot arrays, and growth at progressively lower temperatures. Continued progress in molecular-precursor chemistry will afford precise control over the crystal structures, nanostructures, and microstructures of electronic materials.

  2. Biochemical Removal of HAP Precursors From Coal

    Energy Technology Data Exchange (ETDEWEB)

    Olson, G.; Tucker, L.; Richards, J.

    1997-07-01

    This project addresses DOE`s interest in advanced concepts for controlling emissions of air toxics from coal-fired utility boilers. We are determining the feasibility of developing a biochemical process for the precombustion removal of substantial percentages of 13 inorganic hazardous air pollutant (HAP) precursors from coal. These HAP precursors are Sb, As, Be, Cd, Cr, Cl, Co, F, Pb, Hg, Mn, Ni, and Se. Although rapid physical coal cleaning is done routinely in preparation plants, biochemical processes for removal of HAP precursors from coal potentially offer advantages of deeper cleaning, more specificity, and less coal loss. Compared to chemical processes for coal cleaning, biochemical processes potentially offer lower costs and milder process conditions. Pyrite oxidizing bacteria, most notably Thiobacillusferrooxidans, are being evaluated in this project for their ability to remove HAP precursors from U.S. coals.

  3. Probabilistic precursor analysis - an application of PSA

    International Nuclear Information System (INIS)

    Hari Prasad, M.; Gopika, V.; Sanyasi Rao, V.V.S.; Vaze, K.K.

    2011-01-01

    Incidents are inevitably part of the operational life of any complex industrial facility, and it is hard to predict how various contributing factors combine to cause the outcome. However, it should be possible to detect the existence of latent conditions that, together with the triggering failure(s), result in abnormal events. These incidents are called precursors. Precursor study, by definition, focuses on how a particular event might have adversely developed. This paper focuses on the events which can be analyzed to assess their potential to develop into core damage situation and looks into extending Probabilistic Safety Assessment techniques to precursor studies and explains the benefits through a typical case study. A preliminary probabilistic precursor analysis has been carried out for a typical NPP. The major advantages of this approach are the strong potential for augmenting event analysis which is currently carried out purely on deterministic basis. (author)

  4. Planar half-cell shaped precursor body

    DEFF Research Database (Denmark)

    2015-01-01

    The invention relates to a half-cell shaped precursor body of either anode type or cathode type, the half-cell shaped precursor body being prepared to be free sintered to form a sintered or pre-sintered half-cell being adapted to be stacked in a solid oxide fuel cell stack. The obtained half......-cell has an improved planar shape, which remains planar also after a sintering process and during temperature fluctuations....

  5. Bright luminescence of Vibrio fischeri aconitase mutants reveals a connection between citrate and the Gac/Csr regulatory system.

    Science.gov (United States)

    Septer, Alecia N; Bose, Jeffrey L; Lipzen, Anna; Martin, Joel; Whistler, Cheryl; Stabb, Eric V

    2015-01-01

    The Gac/Csr regulatory system is conserved throughout the γ-proteobacteria and controls key pathways in central carbon metabolism, quorum sensing, biofilm formation and virulence in important plant and animal pathogens. Here we show that elevated intracellular citrate levels in a Vibrio fischeri aconitase mutant correlate with activation of the Gac/Csr cascade and induction of bright luminescence. Spontaneous or directed mutations in the gene that encodes citrate synthase reversed the bright luminescence of aconitase mutants, eliminated their citrate accumulation and reversed their elevated expression of CsrB. Our data elucidate a correlative link between central metabolic and regulatory pathways, and they suggest that the Gac system senses a blockage at the aconitase step of the tricarboxylic acid cycle, either through elevated citrate levels or a secondary metabolic effect of citrate accumulation, and responds by modulating carbon flow and various functions associated with host colonization, including bioluminescence. © 2014 John Wiley & Sons Ltd.

  6. Plasma Membrane Na+-Coupled Citrate Transporter (SLC13A5 and Neonatal Epileptic Encephalopathy

    Directory of Open Access Journals (Sweden)

    Yangzom D. Bhutia

    2017-02-01

    Full Text Available SLC13A5 is a Na+-coupled transporter for citrate that is expressed in the plasma membrane of specific cell types in the liver, testis, and brain. It is an electrogenic transporter with a Na+:citrate3− stoichiometry of 4:1. In humans, the Michaelis constant for SLC13A5 to transport citrate is ~600 μM, which is physiologically relevant given that the normal concentration of citrate in plasma is in the range of 150–200 μM. Li+ stimulates the transport function of human SLC13A5 at concentrations that are in the therapeutic range in patients on lithium therapy. Human SLC13A5 differs from rodent Slc13a5 in two important aspects: the affinity of the human transporter for citrate is ~30-fold less than that of the rodent transporter, thus making human SLC13A5 a low-affinity/high-capacity transporter and the rodent Slc13a5 a high-affinity/low-capacity transporter. In the liver, SLC13A5 is expressed exclusively in the sinusoidal membrane of the hepatocytes, where it plays a role in the uptake of circulating citrate from the sinusoidal blood for metabolic use. In the testis, the transporter is expressed only in spermatozoa, which is also only in the mid piece where mitochondria are located; the likely function of the transporter in spermatozoa is to mediate the uptake of citrate present at high levels in the seminal fluid for subsequent metabolism in the sperm mitochondria to generate biological energy, thereby supporting sperm motility. In the brain, the transporter is expressed mostly in neurons. As astrocytes secrete citrate into extracellular medium, the potential function of SLC13A5 in neurons is to mediate the uptake of circulating citrate and astrocyte-released citrate for subsequent metabolism. Slc13a5-knockout mice have been generated; these mice do not have any overt phenotype but are resistant to experimentally induced metabolic syndrome. Recently however, loss-of-function mutations in human SLC13A5 have been found to cause severe epilepsy

  7. Effectiveness of Sodium Picosulfate/Magnesium Citrate (PICO) for Colonoscopy Preparation

    Science.gov (United States)

    Suh, Wu Seok; Jeong, Jin Sik; Kim, Dong Sik; Kim, Sang Woo; Kwak, Dong Min; Hwang, Jong Seong; Kim, Hyun Jin; Park, Man Woo; Shim, Min Chul; Koo, Ja-Il; Kim, Jae Hwang; Shon, Dae Ho

    2014-01-01

    Purpose Bowel preparation with sodium phosphate was recently prohibited by the U.S. Food and Drug Administration. Polyethylene glycol (PEG) is safe and effective; however, it is difficult to drink. To identify an easy bowel preparation method for colonoscopy, we evaluated three different bowel preparation regimens regarding their efficacy and patient satisfaction. Methods In this randomized, comparative study, 892 patients who visited a secondary referral hospital for a colonoscopy between November 2012 and February 2013 were enrolled. Three regimens were evaluated: three packets of sodium picosulfate/magnesium citrate (PICO, group A), two packets of PICO with 1 L of PEG (PICO + PEG 1 L, group B), and two packets of PICO with 2 L of PEG (PICO + PEG 2 L, group C). A questionnaire survey regarding the patients' preference for the bowel preparation regimen and satisfaction was conducted before the colonoscopies. The quality of bowel cleansing was scored by the colonoscopists who used the Aronchick scoring scale and the Ottawa scale. Results The patients' satisfaction rate regarding the regimens were 72% in group A, 64% in group B, and 45.9% in group C. Nausea and abdominal bloating caused by the regimens were more frequent in group C than in group A or group B (P < 0.01). Group C showed the lowest preference rate compared to the other groups (P < 0.01). Group C showed better right colon cleansing efficacy than group A or group B. Conclusion Group A exhibited a better result than group B or group C in patient satisfaction and preference. In the cleansing quality, no difference was noted between groups A and C. PMID:25360429

  8. Operational experience feedback with precursor analysis

    International Nuclear Information System (INIS)

    Koncar, M.; Ferjancic, M.; Muehleisen, A.; Vojnovic, D.

    2003-01-01

    Experience of practical operation is a valuable source of information for improving the safety and reliability of nuclear power plants. Operational experience feedback (Olef) system manages this aspect of NPP operation. The traditional ways of investigating operational events, such as the root cause analysis (RCA), are predominantly qualitative. RCA as a part of the Olef system provides technical guidance and management expectations in the conduct of assessing the root cause to prevent recurrence, covering the following areas: conditions preceding the event, sequence of events, equipment performance and system response, human performance considerations, equipment failures, precursors to the event, plant response and follow-up, radiological considerations, regulatory process considerations and safety significance. The root cause of event is recognized when there is no known answer on question 'why has it happened?' regarding relevant condition that may have affected the event. At that point the Olef is proceeding by actions taken in response to events, utilization, dissemination and exchange of operating experience information and at the end reviewing the effectiveness of the Olef. Analysis of the event and the selection of recommended corrective/preventive actions for implementation and prioritization can be enhanced by taking into account the information and insights derived from Pasa-based analysis. A Pasa based method, called probabilistic precursor event analysis (PPE A) provides a complement to the RCA approach by focusing on how an event might have developed adversely, and implies the mapping of an operational event on a probabilistic risk model of the plant in order to obtain a quantitative assessment of the safety significance of the event PSA based event analysis provides, due to its quantitative nature, appropriate prioritization of corrective actions. PPEA defines requirements for PSA model and code, identifies input requirements and elaborates following

  9. A new electrochemical sensor containing a film of chitosan-supported ruthenium: detection and quantification of sildenafil citrate and acetaminophen

    Energy Technology Data Exchange (ETDEWEB)

    Delolo, Fabio Godoy; Rodrigues, Claudia; Silva, Monize Martins da; Batista, Alzir Azevedo, E-mail: fabiodelolo@hotmail.com, E-mail: daab@power.ufscar.br [Universidade Federal de Sao Carlos (UFSCar), SP (Brazil). Departamento de Quimica. Lab. de Estrutura e Reatividade de Compostos Inorganicos; Dinelli, Luis Rogerio [Universidade Federal de Uberlandia (UFU), Ituiutaba, MG (Brazil). Faculdade de Ciencias Integradas do Pontal; Delling, Felix Nicolai; Zukerman-Schpector, Julio [Universidade Federal de Sao Carlos (UFSCar), SP (Brazil). Departamento de Quimica. Lab. de Cristalografia Estereodinamica e Modelagem Molecular

    2014-03-15

    This work presents the construction of a novel electrochemical sensor for detection of organic analytes, using a glassy carbon electrode (GCE) modified with a chitosan-supported ruthenium film. The ruthenium-chitosan film was obtained starting from the mer-[RuCl{sub 3}(dppb)(H{sub 2}O)] complex as a [1,4-bis(diphenylphosphine)butane] (dppb) precursor, and chitosan (QT). The structure of the chitosan-supported ruthenium film on the surface of the glassy carbon electrode was characterized by UV-Vis spectroscopy, electron paramagnetic resonance (EPR), scanning electron microscopy (SEM), atomic force microscopy (AFM), powder X-ray diffraction (XRD) and atomic absorption spectroscopy (AAS) techniques. The glassy carbon electrode was modified with a film formed from the evaporation of 5 μL of a solution composed of 5 mg chitosan-supported ruthenium (RuQT) in 10 mL of 0.1 mol L{sup -1} acetic acid. The modified electrode was tested as a sensor for sildenafil citrate (Viagra® 50 mg) and acetaminophen (Tylenol®) detection. The technique utilized for these analyses was differential pulse voltammetry (DPV) in 0.1 mol L{sup -1} H{sub 2}SO{sub 4} (pH 1.0) and 0.1 mol L{sup -1} CH{sub 3}COOK (pH 6.5) as supporting electrolyte. All analyses were carried out during a month using the same electrode. The electrode was washed only with water in between the analyses, keeping it in the refrigerator when it was not in use. This electrode was stable during the period utilized showing no degradation and presenting a linear response over the evaluated concentration interval (1.25 × 10{sup -5} to 4.99 × 10{sup -4} mol L{sup -1}). (author)

  10. A new electrochemical sensor containing a film of chitosan-supported ruthenium: detection and quantification of sildenafil citrate and acetaminophen

    International Nuclear Information System (INIS)

    Delolo, Fabio Godoy; Rodrigues, Claudia; Silva, Monize Martins da; Batista, Alzir Azevedo; Dinelli, Luis Rogerio; Delling, Felix Nicolai; Zukerman-Schpector, Julio

    2014-01-01

    This work presents the construction of a novel electrochemical sensor for detection of organic analytes, using a glassy carbon electrode (GCE) modified with a chitosan-supported ruthenium film. The ruthenium-chitosan film was obtained starting from the mer-[RuCl 3 (dppb)(H 2 O)] complex as a [1,4-bis(diphenylphosphine)butane] (dppb) precursor, and chitosan (QT). The structure of the chitosan-supported ruthenium film on the surface of the glassy carbon electrode was characterized by UV-Vis spectroscopy, electron paramagnetic resonance (EPR), scanning electron microscopy (SEM), atomic force microscopy (AFM), powder X-ray diffraction (XRD) and atomic absorption spectroscopy (AAS) techniques. The glassy carbon electrode was modified with a film formed from the evaporation of 5 μL of a solution composed of 5 mg chitosan-supported ruthenium (RuQT) in 10 mL of 0.1 mol L -1 acetic acid. The modified electrode was tested as a sensor for sildenafil citrate (Viagra® 50 mg) and acetaminophen (Tylenol®) detection. The technique utilized for these analyses was differential pulse voltammetry (DPV) in 0.1 mol L -1 H 2 SO 4 (pH 1.0) and 0.1 mol L -1 CH 3 COOK (pH 6.5) as supporting electrolyte. All analyses were carried out during a month using the same electrode. The electrode was washed only with water in between the analyses, keeping it in the refrigerator when it was not in use. This electrode was stable during the period utilized showing no degradation and presenting a linear response over the evaluated concentration interval (1.25 × 10 -5 to 4.99 × 10 -4 mol L -1 ). (author)

  11. Dynamic stabilization of disruption precursors in tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Maoquan, Wang; Jianshan, Mao; Yuan, Pan [Academia Sinica, Hefei, AH (China). Inst. of Plasma Physics

    1994-12-01

    A method for dynamic stabilization of the disruption precursors in tokamak is proposed, that is a controlled ac current induced and added to the equilibrium current. The ac currents applied can be a sine alternative current with a relevant frequency, or a pulsed current with a suitable pulsed width {tau} and or a discontinuous pulsed current whose width {tau} is very shorter than the intervals between pulses, and or a `sawtooth` pulsed current with the time of ramp phase of the sawtooth is very much shorter than the sawtooth descending time, the ratio of them can be {<=}10{sup -3}. The physical model of the ac current drive is analyzed in detail. The suppression role of the ac current on the MHD perturbations was analyzed in theory and proved numerically. It is indicated that the ac current can make the discontinuous derivative, {Delta}`, more favorable for the tearing mode stabilities, and so, as long as the parameters of the applied ac currents are selected suitably, the MHD perturbations can be suppressed effectively, the perturbations will be in the zero-growing state, the profile of the plasma current and temperature remain in the initial states and not variate basically, the tokamak be in the stabilized operation state. (8 figs.).

  12. Thermogravimetric evaluation of the suitability of precursors for MOCVD

    International Nuclear Information System (INIS)

    Kunte, G V; Shivashankar, S A; Umarji, A M

    2008-01-01

    A method based on the Langmuir equation for the estimation of vapour pressure and enthalpy of sublimation of subliming compounds is described. The variable temperature thermogravimetric/differential thermogravimetric (TG/DTG) curve of benzoic acid is used to arrive at the instrument parameters. Employing these parameters, the vapour pressure–temperature curves are derived for salicylic acid and camphor from their TG/DTG curves. The values match well with vapour pressure data in the literature, obtained by effusion methods. By employing the Clausius–Clapeyron equation, the enthalpy of sublimation could be calculated. Extending the method further, two precursors for metal-organic chemical vapour deposition (MOCVD) of titanium oxide bis-isopropyl bis tert-butyl 2-oxobutanoato titanium, Ti(O i Pr) 2 (tbob) 2 , and bis-oxo-bis-tertbutyl 2-oxobutanoato titanium, [TiO(tbob) 2 ] 2 , have been evaluated. The complex Ti(O i Pr) 2 (tbob) 2 is found to be a more suitable precursor. This approach can be helpful in quickly screening for the suitability of a compound as a CVD precursor

  13. Aqueous solubility of calcium citrate and interconversion between the tetrahydrate and the hexahydrate as a balance between endothermic dissolution and exothermic complex formation

    DEFF Research Database (Denmark)

    Hedegaard, Martina Vavrusova; Skibsted, Leif Horsfelt

    2016-01-01

    Aqueous solubility of calcium citrate tetrahydrate was found to decrease with increasing temperature, while solubility of hexahydrate increased with a transition temperature at 51.6 °C. Excess citrate increased calcium citrate solubility but decreased the calcium ion activity of the saturated sol...

  14. THE SURFACE PHOTOCHEMISTRY OF PROCYMIDONE IN PRESENCE OF AMMONIUM FERRIC CITRATE

    Directory of Open Access Journals (Sweden)

    Ivan Osipov

    2015-12-01

    Full Text Available Procymidone was chosen as the model compound and its phototransformation was followed under sunlight irradiation. The main photodegradation products on silica is 3,5-dichloroaniline and 3,5-diclorphenilisocyanate. The use of ammonium ferric citrate enhances the degradation of the procymidone.

  15. Urinary acidification and urinary excretion of calcium and citrate in women with bilateral medullary sponge kidney

    DEFF Research Database (Denmark)

    Osther, P J; Mathiasen, Helle; Hansen, A B

    1994-01-01

    Urinary acidification ability, acid-base status and urinary excretion of calcium and citrate were evaluated in 10 women with bilateral medullary sponge kidney (MSK) and in 10 healthy women. Patients with MSK had higher fasting urine pH compared to normal controls (p ... in the mechanism of hypercalciuria and hypocitraturia in patients with medullary sponge kidney.(ABSTRACT TRUNCATED AT 250 WORDS)...

  16. Structural and Thermodynamic Analysis of the First Mononuclear Aqueous Aluminum Citrate Complex Using DFT Calculations.

    Science.gov (United States)

    de Noronha, Antonio Luiz Oliveira; Guimarães, Luciana; Duarte, Hélio Anderson

    2007-05-01

    Structural and thermodynamic properties of the mononuclear Al/citrate complexes have been theoretically investigated aiming to understand the coordination mechanism at an atomic level. GGA-DFT/PCM calculations have been performed for the different conformations and tautomers arising from the Al(3+) and citric acid (H3L) interaction in aqueous solution. The Gibbs reaction energies were estimated based on the reaction of the trigonal planar Al(OH)3 and H3L to form different Al-citrate complexes. The estimated Gibbs free reaction energies for the [AlL], [AlHL](+), and [Al(OH)L](-) species are in good agreement with the experimental values. In these species, the Al(3+) center is coordinated by two carboxylic and the tertiary hydroxyl groups of the citrate. Conversely to what has been proposed based on the experiments, the present theoretical calculations indicate that the citric acid hydroxyl group remains protonated upon the coordination of Al(3+). In fact, our model turns out to be more consistent with the relative pKa values of citrate protonation groups and with the hydrolysis constant of the H2O bound to Al(3+) leading to better agreement with the available experimental data.

  17. 77 FR 24461 - Citric Acid and Certain Citrate Salts From Canada: Final Results of Antidumping Duty...

    Science.gov (United States)

    2012-04-24

    ... that satisfies the standards set forth in the United States Pharmacopeia and has been mixed with a... meaning of 19 CFR 351.106(c)(1), in which case the cash deposit rate will be zero; (2) for previously.... See Citric Acid and Certain Citrate Salts from Canada and the People's Republic of China: Antidumping...

  18. Structure and elevator mechanism of the Na(+)-citrate transporter CitS

    NARCIS (Netherlands)

    Lolkema, Juke S; Slotboom, Dirk Jan

    2016-01-01

    The recently determined crystal structure of the bacterial Na(+)-citrate symporter CitS provides unexpected structural and mechanistic insights. The protein has a fold that has not been seen in other proteins, but the oligomeric state, domain organization and proposed transport mechanism strongly

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

    NARCIS (Netherlands)

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

    2012-01-01

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

  20. 75 FR 14491 - Listing of Color Additives Exempt From Certification; Bismuth Citrate

    Science.gov (United States)

    2010-03-26

    ... DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration 21 CFR Part 73 [Docket No... Safety and Applied Nutrition (HFS-265), Food and Drug Administration, 5100 Paint Branch Pkwy., College... results from a 90-day oral toxicity study on bismuth citrate in rats, genotoxicity studies, dermal...

  1. Fast and simple preparation of 68Ga-citrate for routine clinical PET

    DEFF Research Database (Denmark)

    Nielsen, Karin M; Kaufmann, Jens; Mewis, Dennis

    2013-01-01

    The imaging of infectious and inflammatory diseases using gallium-67 (⁶⁷Ga) citrate scintigraphy has been a well-established diagnostic tool for decades. In recent times, interest has focused on PET using the short-lived positron emitting radioisotope ⁶⁸Ga. ⁶⁸Ga is not only more readily available...

  2. Fast and simple one-step preparation of Ga-68 citrate for routine clinical PET

    DEFF Research Database (Denmark)

    Jensen, Svend B.; Nielsen, Karin M.; Mewis, Dennis

    2013-01-01

    The imaging of infectious and inflammatory diseases using gallium-67 (Ga-67) citrate scintigraphy has been a well-established diagnostic tool for decades. In recent times, interest has focused on PET using the short-lived positron emitting radioisotope Ga-68. Ga-68 is not only more readily...

  3. Cupric citrate as growth promoter for broiler chickens in different rearing stages

    International Nuclear Information System (INIS)

    Brainer, Monica Maria de Almeida; Menten, Jose Fernando Machado; Vale, Marcos Martinez do; Morais, Sonia Cristina Daroz de

    2003-01-01

    Feeding cupric citrate as alternative to cupric sulfate to broilers has been suggested in the literature. Day-old male broiler chicks (1,200) were used in an experiment to evaluate the efficacy of cupric citrate supplementation (75 mg Cu kg-1) during the 1-21, 22-42 or 1-42 d periods in comparison to an unsupplemented diet and a diet supplemented with cupric sulfate (200 mg Cu kg-1, 1-42 d). A randomized block design was used, with five treatments, six replicates and 40 birds per pen. The diets, based on corn and soybean meal, and water were offered ad libitum during the 42-day experimental period. Over the entire period, there was no effect of copper supplementation (P > 0.05) on bird live weight, weight gain, feed intake, feed conversion and mortality. Cupric citrate supplementation on the 22-42 d period resulted in worse feed conversion as compared to broilers receiving cupric sulfate (2.014 vs. 1.967, P < 0.05). Copper residues in the litter were reduced when broilers were fed cupric citrate, as compared to cupric sulfate (P < 0.01). The absence of response to copper supplementation can be attributed to the environmental and sanitary rearing conditions

  4. 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 ...

  5. Beliefs and social norms about sildenafil citrate (Viagra) misuse and perceived consequences among Houstonian teenage males.

    Science.gov (United States)

    Peters, Ronald J; Johnson, Regina J; Kelder, Steve; Meshack, Angela F; Jefferson, Troy

    2007-09-01

    In the current study, a qualitative approach was used to investigate relevant beliefs and norms associated with sildenafil citrate (Viagra) consumption, initiation, and perceived consequences. Focus groups were conducted with 43 young men aged 18 and 19 years who identified themselves as lifetime sildenafil citrate users. The majority of focus group participants believed that "curiosity" and "peer pressure" contributed to their initial use. Most revealed that they first heard about sildenafil citrate from television advertisements, family members, friends, or sporting events, and they were able to obtain the drug from their friends and family members or they stole it from their father or grandfather. These findings may highlight the relative importance of exposure to prescription drug messages among those to whom the message is not specifically targeted, that is, young men. It is possible that the sildenafil citrate television messages are recalled by not only older male audiences but also by teenagers and younger men, producing similar cognitive processing and curiosity in both age cohorts.

  6. Sildenafil citrate (Viagra) impairs fertilization and early embryo development in mice.

    Science.gov (United States)

    Glenn, David R J; McClure, Neil; Cosby, S Louise; Stevenson, Michael; Lewis, Sheena E M

    2009-03-01

    To determine the effects of sildenafil citrate, a cyclic monophosphate-specific type 5 phosphodiesterase inhibitor known to affect sperm function, on fertilization and early embryo cleavage. This acute mammal study included male and female mice assigned randomly, the females sacrificed after mating and their oocytes/embryos evaluated at four time periods after treatment. Academic research environment. Male and female CBAB(6) mice. Female mice were injected intraperitoneally with 5 IU gonadotropin (hCG) to stimulate follicular growth and induce ovulation. They were each caged with a male that had been gavaged with sildenafil citrate (0.06 mg/0.05 mL) and allowed to mate. After 12, 36, 60, and 84 h, females were killed, their oviducts were dissected out, and retrieved embryos were assessed for blastomere number and quality. Fertilization rates and numbers of embryos were evaluated after treatment. Fertilization rates (day 1) were markedly reduced (-33%) in matings where the male had taken sildenafil citrate. Over days 2-4, the numbers of embryos developing in the treated group were significantly fewer than in the control group. There was also a trend for impaired cleavage rates within those embryos, although this did not reach significance. The impairments to fertility caused by sildenafil citrate have important implications for infertility centers and for couples who are using this drug precoitally while attempting to conceive.

  7. Cupric citrate as growth promoter for broiler chickens in different rearing stages

    Energy Technology Data Exchange (ETDEWEB)

    Brainer, Monica Maria de Almeida [EAFCe, Ceres, GO (Brazil). Dept. de Zootecnia; Menten, Jose Fernando Machado; Vale, Marcos Martinez do; Morais, Sonia Cristina Daroz de [Universidade de Sao Paulo (USP), Piracicaba, SP (Brazil). Escola Superior de Agricultura Luiz de Queiroz (ESALQ). Dept. de Zootecnia]. E-mail: jfmmente@esalq.usp.br

    2003-07-01

    Feeding cupric citrate as alternative to cupric sulfate to broilers has been suggested in the literature. Day-old male broiler chicks (1,200) were used in an experiment to evaluate the efficacy of cupric citrate supplementation (75 mg Cu kg-1) during the 1-21, 22-42 or 1-42 d periods in comparison to an unsupplemented diet and a diet supplemented with cupric sulfate (200 mg Cu kg-1, 1-42 d). A randomized block design was used, with five treatments, six replicates and 40 birds per pen. The diets, based on corn and soybean meal, and water were offered ad libitum during the 42-day experimental period. Over the entire period, there was no effect of copper supplementation (P > 0.05) on bird live weight, weight gain, feed intake, feed conversion and mortality. Cupric citrate supplementation on the 22-42 d period resulted in worse feed conversion as compared to broilers receiving cupric sulfate (2.014 vs. 1.967, P < 0.05). Copper residues in the litter were reduced when broilers were fed cupric citrate, as compared to cupric sulfate (P < 0.01). The absence of response to copper supplementation can be attributed to the environmental and sanitary rearing conditions.

  8. Effect of bismuth citrate, lactose, and organic acid on necrotic enteritis in broilers

    Science.gov (United States)

    Clostridium perfringens – associated necrotic enteritis causes significant losses and increased morbidity in poultry. The objective of this study was to evaluate the effect of bismuth citrate and acidifiers on the development of necrotic enteritis in broilers. The first study was a dose response t...

  9. 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.

  10. Study on the Antimicrobial Properties of Citrate-Based Biodegradable Polymers

    Directory of Open Access Journals (Sweden)

    Lee-Chun eSu

    2014-07-01

    Full Text Available Citrate-based polymers possess unique advantages for various biomedical applications since citric acid is a natural metabolism product, which is biocompatible and antimicrobial. In polymer synthesis, citric acid also provides multiple functional groups to control the crosslinking of polymers and active binding sites for further conjugation of biomolecules. Our group recently developed a number of citrate-based polymers for various biomedical applications by taking advantage of their controllable chemical, mechanical, and biological characteristics. In this study, various citric acid derived biodegradable polymers were synthesized and investigated for their physicochemical and antimicrobial properties. Results indicate that citric acid derived polymers reduced bacterial proliferation to different degrees based on their chemical composition. Among the studied polymers, poly(octamethylene citrate (POC showed approximately 70-80% suppression to microbe proliferation, owing to its relatively higher ratio of citric acid contents. Crosslinked urethane-doped polyester elastomers (CUPEs and biodegradable photoluminescent polymers (BPLPs also exhibited significant bacteria reduction of ~20% and ~50% for Staphylococcus aureus and Escherichia coli, respectively. Thus, the intrinsic antibacterial properties in citrate-based polymers enable them to inhibit bacteria growth without incorporation of antibiotics, silver nanoparticles, and other traditional bacteria-killing agents suggesting that they are unique beneficial materials for wound dressing, tissue engineering, and other potential medical applications where antimicrobial property is desired.

  11. Gallium-67 Citrate uptake in cryptoccal thyroiditis in a Homosexual male

    International Nuclear Information System (INIS)

    Machac, J.; Nejatheim, M.; Goldsmith, S.J.

    1985-01-01

    A case of disseminated cryptococcosis and autopsy proven cryptococcal thyroiditis is described in a homosexual male. Thyroid uptake of Gallium-67 citrate was seen one week prior to positive blood cultures. This finding was the sole indication of thyroid involvement. Focal Gallium uptake may be considered as an indication for biopsy and culture in the initial work up of this group of immunocompromised hosts

  12. The structure and binding mode of citrate in the stabilization of gold nanoparticles

    KAUST Repository

    Al-Johani, Hind

    2017-03-27

    Elucidating the binding mode of carboxylate-containing ligands to gold nanoparticles (AuNPs) is crucial to understand their stabilizing role. A detailed picture of the three-dimensional structure and coordination modes of citrate, acetate, succinate and glutarate to AuNPs is obtained by 13C and 23Na solid-state NMR in combination with computational modelling and electron microscopy. The binding between the carboxylates and the AuNP surface is found to occur in three different modes. These three modes are simultaneously present at low citrate to gold ratios, while a monocarboxylate monodentate (1κO1) mode is favoured at high citrate:gold ratios. The surface AuNP atoms are found to be predominantly in the zero oxidation state after citrate coordination, although trace amounts of Auδ+ are observed. 23Na NMR experiments show that Na+ ions are present near the gold surface, indicating that carboxylate binding occurs as a 2e− L-type interaction for each oxygen atom involved. This approach has broad potential to probe the binding of a variety of ligands to metal nanoparticles.

  13. The structure and binding mode of citrate in the stabilization of gold nanoparticles

    KAUST Repository

    Al-Johani, Hind; Abou-Hamad, Edy; Jedidi, Abdesslem; Widdifield, Cory M.; Viger-Gravel, Jasmine; Sangaru, Shiv; Gajan, David; Anjum, Dalaver H.; Ould-Chikh, Samy; Hedhili, Mohamed N.; Gurinov, Andrei; Kelly, Michael J.; El Eter, Mohamad; Cavallo, Luigi; Basset, Jean-Marie; Basset, Jean-Marie

    2017-01-01

    Elucidating the binding mode of carboxylate-containing ligands to gold nanoparticles (AuNPs) is crucial to understand their stabilizing role. A detailed picture of the three-dimensional structure and coordination modes of citrate, acetate, succinate and glutarate to AuNPs is obtained by 13C and 23Na solid-state NMR in combination with computational modelling and electron microscopy. The binding between the carboxylates and the AuNP surface is found to occur in three different modes. These three modes are simultaneously present at low citrate to gold ratios, while a monocarboxylate monodentate (1κO1) mode is favoured at high citrate:gold ratios. The surface AuNP atoms are found to be predominantly in the zero oxidation state after citrate coordination, although trace amounts of Auδ+ are observed. 23Na NMR experiments show that Na+ ions are present near the gold surface, indicating that carboxylate binding occurs as a 2e− L-type interaction for each oxygen atom involved. This approach has broad potential to probe the binding of a variety of ligands to metal nanoparticles.

  14. Citrate, malate and alkali content in commonly consumed diet sodas: implications for nephrolithiasis treatment.

    Science.gov (United States)

    Eisner, Brian H; Asplin, John R; Goldfarb, David S; Ahmad, Ardalanejaz; Stoller, Marshall L

    2010-06-01

    Citrate is a known inhibitor of calcium stone formation. Dietary citrate and alkali intake may have an effect on citraturia. Increasing alkali intake also increases urine pH, which can help prevent uric acid stones. We determined citrate, malate and total alkali concentrations in commonly consumed diet sodas to help direct dietary recommendations in patients with hypocitraturic calcium or uric acid nephrolithiasis. Citrate and malate were measured in a lemonade beverage commonly used to treat hypocitraturic calcium nephrolithiasis and in 15 diet sodas. Anions were measured by ion chromatography. The pH of each beverage was measured to allow calculation of the unprotonated anion concentration using the known pK of citric and malic acid. Total alkali equivalents were calculated for each beverage. Statistical analysis was done using Pearson's correlation coefficient. Several sodas contained an amount of citrate equal to or greater than that of alkali and total alkali as a lemonade beverage commonly used to treat hypocitraturic calcium nephrolithiasis (6.30 mEq/l citrate as alkali and 6.30 as total alkali). These sodas were Diet Sunkist Orange, Diet 7Up, Sprite Zero, Diet Canada Dry Ginger Ale, Sierra Mist Free, Diet Orange Crush, Fresca and Diet Mountain Dew. Colas, including Caffeine Free Diet Coke, Coke Zero, Caffeine Free Diet Pepsi and Diet Coke with Lime, had the lowest total alkali (less than 1.0 mEq/l). There was no significant correlation between beverage pH and total alkali content. Several commonly consumed diet sodas contain moderate amounts of citrate as alkali and total alkali. This information is helpful for dietary recommendations in patients with calcium nephrolithiasis, specifically those with hypocitraturia. It may also be useful in patients with low urine pH and uric acid stones. Beverage malate content is also important since malate ingestion increases the total alkali delivered, which in turn augments citraturia and increases urine pH. Copyright

  15. Na/K citrate versus sodium bicarbonate in prevention of contrast-induced nephropathy

    Directory of Open Access Journals (Sweden)

    Sameh Mohamed Abouzeid

    2016-01-01

    Full Text Available Contrast-induced nephropathy (CIN is one of the important complications of radiographic procedures, especially in patients with chronic kidney disease. It is also one of the common causes of acute kidney injury. The pathogenesis is postulated to be the effect of oxygen- free radicals and hyperosmolar stress on the renal medulla. It is reported that the production of superoxide is most active at acid environment. K/Na citrate is well known as a urine alkalini- zation medium, and this has been evaluated earlier with standard hydration for reduction of CIN and was stated to be efficient. We aimed to determine the efficacy of Na/K citrate in reducing the frequency of CIN in comparison to sodium bicarbonate in patients after coronary angiography. Two hundred and ten patients with renal dysfunction [estimated glomerular filtration rate (eGFR, 60 mL/min/1.73 m2or less] who underwent elective or emergency coronary angiography (CAG with/without percutaneous coronary intervention (PCI at our institution were enrolled into the study. The patients were randomized into two groups, Group 1-Taking Na/K citrate and Group 2-Taking sodium bicarbonate. Radiographic contrast agent iohexol was used. Change in creatinine, percent change in creatinine, percent change in eGFR, change in serum potassium, and urine pH were all compared between the two groups. There was no significant difference for prevention of CIN when comparing the Na/K citrate with sodium bicarbonate solution in patients exposed to CAG with or without PCI. Mean absolute change in eGFR after 48 h after administration of contrast between sodium bicarbonate group and Na/K citrate group was −0.60 ± 1.58 versus −0.71 ± 1.38. Serum potassium decreased postprocedure in the sodium bicarbonate group than in the citrate group (3.90 ± 0.33 vs. 4.14 ± 0.39. Both agents are equally effective in reducing the incidence of CIN, but the citrate would possibly be a safer option for patients at risk of

  16. A prospective randomized trial comparing the efficacy of Letrozole and Clomiphene citrate in induction of ovulation in polycystic ovarian syndrome

    Directory of Open Access Journals (Sweden)

    Kallol Kumar Roy

    2012-01-01

    Full Text Available Objectives: To compare the efficacy of letrozole and clomiphene citrate (CC in patients of anovulatory polycystic ovarian syndrome (PCOS with infertility. Materials and Methods: This prospective randomized clinical trial included 204 patients of PCOS. 98 patients (294 cycles received 2.5-5 mg of letrozole; 106 patients (318 cycles received 50-100 mg of CC (both orally from Days 3-7 of menstrual cycle. The treatment continued for three cycles in both the groups. Main outcome measures: ovulation rate, endometrial thickness, and pregnancy rate. Statistical analysis was done using SPSS 13 software. P value less than 0.05 was considered significant. Results: The mean number of dominant follicles in letrozole groups and CC groups was 1.86±0.26 and 1.92±0.17, respectively (P=0.126. Number of ovulatory cycle in letrozole group was 196 (66.6% versus 216 (67.9% in CC group (P=0.712. The mean mid-cycle endometrial thickness was 9.1±0.3 mm in letrozole group and 6.3±1.1 in CC group, which was statistically significant (P=0.014. The mean Estradiol [E2] level in clomiphene citrate group was significantly higher in CC group (364.2±71.4 pg/mL than letrozole group (248.2± 42.2 pg/mL. 43 patients from the letrozole group (43.8% and 28 patients from the CC group (26.4% became pregnant. Conclusion: Letrozole and CC have comparable ovulation rate. The effect of letrozole showed a better endometrial response and pregnancy rate compared with CC.

  17. Comparing the Effectivities of Chitosan Citrate and Chitosan Acetate in Eradicating Enterococcus faecalis Biofilm

    Directory of Open Access Journals (Sweden)

    Uppalavanna Witedja

    2018-01-01

    Full Text Available Introduction: Adequate biomechanical preparations, antibacterial irrigants, and intracanal medications to promote the elimination of bacteria and their products are required to succeed root canal treatment. Enterococcus faecalis with its biofilm is known as an important etiological agent in endodontic treatment failures. Chitosan, as a natural product, has an antibacterial activity and is considered less toxic to the periapical tissue than other irrigants. However, the use of this natural product needs to be examined to determine its effectiveness as a root canal irrigant in endodontic treatment; this can be done by comparing it with the most common endodontic irrigant (NaOCl 5.25% as a positive control. Objective: The objective of the study was to compare the effectiveness between 1–3% chitosan acetate (CA and 1–3% chitosan citrate (CC against E. faecalis biofilm formation after treatment for 15, 30, and 60 minutes. Methods: The study was conducted using 12 groups, including 1–3% CA, 1–3% CC, and control groups. E. faecalis biofilms in 96-well plates were exposed to each sample for 15, 30, or 60 minutes. Subsequently, the biofilms were stained with crystal violet solution, and the optical density value was measured using a microtiter plate reader at a wavelength of 600nm. Results: CA and CC were effective in eradicating E. faecalis biofilm. However, the levels of effectiveness of CC and CA depended on the concentration and application time. Three-way analysis of variance (ANOVA showed a significant difference between the irrigants (F = 5.92; p<0.05 and three application times (F = 6.50; p< 0.05. The CA was effective in eradicating biofilm after 15 minutes of application, whereas the CC was more effective after 30 and 60 minutes of application. Conclusion: CC and CA are both effective in eradicating E. faecalis biofilm.

  18. Developmental toxicity of orally administered sildenafil citrate (Viagra) in SWR/J mice.

    Science.gov (United States)

    Abou-Tarboush, Faisal Mohamed; Abdel-Samad, Mohamed Fathy; Al-Meteri, Mokhlid Hamed

    2011-04-01

    Normal adult inbred SWR/J mice were used to investigate the teratogenic and other possible toxic effects of various dose levels of sildenafil citrate (Viagra) on fetuses. Multiple dose levels of 6.5, 13.0, 19.5, 26.0, 32.5 or 40.0 mg of sildenafil citrate/kg body weight (which correspond to the multiples of 1, 2, 3, 4, 5 or 6 of human 50 mg Viagra, respectively) were orally administered into pregnant mice on days 7-9, 10-12 or 13-15 of gestation. On day 17 of pregnancy, all fetuses were removed and examined for toxic phenomena (embryo-fetal toxicity) and for external, internal and skeletal malformations. A total of 285 pregnant mice were used in the present study. None of the dams treated with sildenafil citrate at any of the oral dose levels used in the present study died during the experimental period and all dams treated with the drug failed to reveal overt signs of maternal toxicity. Moreover, the results of the present study clearly demonstrate that none of the multiple oral dose levels of the drug at any time interval used has induced any external, internal or skeletal malformations in the fetuses obtained from treated females. However, the dose level of 40 mg/kg body weight of sildenafil citrate has a growth suppressing effect on alive fetuses when it was administered at all the time intervals used in the present study. Furthermore, the dose levels 26.0, 32.5 and 40 mg/kg of the drug have embryo-fetal toxicity when the drug is applied on days 13-15 of gestation. The possible mechanisms involved in the embryo-fetal toxicity and fetal growth suppressing effects of sildenafil citrate were discussed. The results of this study have important implications for the widespread use of this drug.

  19. Analysis of dependent failures in the ORNL precursor study

    International Nuclear Information System (INIS)

    Ballard, G.M.

    1985-01-01

    The study of dependent failures (or common cause/mode failures) in the safety assessment of potentially hazardous plant is one of the significant areas of uncertainty in performing probabilistic safety studies. One major reason for this uncertainty is that data on dependent failures is apparently not readily available in sufficient quantity to assist in the development and validation of models. The incident reports that were compiled for the ORNL study on Precursors to Severe Core Damage Accidents (NUREG/CR-2497) provide an opportunity to look at the importance of dependent failures in the most significant incidents of recent reactor operations, to look at the success of probabilistic risk assessment (PRA) methods in accounting for the contribution of dependent failures, and to look at the dependent failure incidents with the aim of identifying the most significant problem areas. In this paper an analysis has been made of the incidents compiled in NUREG/CR-2497 and events involving multiple failures which were not independent have been identified. From this analysis it is clear that dependent failures are a very significant contributor to the precursor incidents. The method of enumeration of accident frequency used in NUREG-2497 can be shown to take account of dependent failures and this may be a significant factor contributing to the apparent difference between the precursor accident frequency and typical PRA frequencies

  20. Spectroscopy Study of Synthetic Forsterite Obtained from Zeolite Precursors

    Directory of Open Access Journals (Sweden)

    Subotić, B.

    2008-02-01

    Full Text Available Important ceramics materials are prepared from aluminosilicate based precursors using novel methods, offering at the same time a better control over many important properties. Forsterite, due to its good refractoriness with melting point at 2163 K, excellent electrical insulation properties even at high temperatures, low dielectric permittivity, thermal expansion and chemical stability, is a material of interest to engineers and designers especially as an active medium for tuneable laser and is also a material of interest to SOFC (Solid oxide fuel cells manufacturers. The aim of this study is to investigate the synthesis of crystalline forsterite using different zeolite precursors previously activated by ball milling. Synthetic forsterite was synthesized from different zeolite precursors and MgO combining highenergy ball milling and thermal treatment of the mixture under determined conditions of time and temperature for each operation. In this research are studied the solid-state phase transformations taking place at temperatures below 1273 K. The obtained products were characterized using different spectroscopy techniques in comparison with surface analysis method and X-ray diffraction.