11 research outputs found
Short-course Benznidazole treatment to reduce Trypanosoma cruzi parasitic load in women of reproductive age (BETTY): A non-inferiority randomized controlled trial study protocol
Background: Retrospective observational studies suggest that transmission of Trypanosoma cruzi does not occur in treated women when pregnant later in life. The level of parasitemia is a known risk factor for congenital transmission. Benznidazole (BZN) is the drug of choice for Preconceptional treatment to reduce parasitic load.The fear of treatment-related side effects limits the implementation of the Argentine guideline recommending BZN 60d/300 mg (or equivalent) treatment of T. cruzi seropositive women during the postpartum period to prevent transmission in a future pregnancy. A short and low dose BZN treatment might reduce major side effects and increase compliance, but its efficacy to reduce T. cruzi parasitic load compared to the standard 60d/300 mg course is not yet established. Clinical trials testing alternative BZN courses among women of reproductive age are urgently needed.Methods and design: We are proposing to perform a double-blinded, non-inferiority randomized controlled trial comparing a short low dose 30-day treatment with BZN 150 mg/day (30d/150 mg) vs. BZN 60d/300 mg. We will recruit not previously treated T. cruzi seropositive women with a live birth during the postpartum period in Argentina, randomize them at 6 months postpartum, and follow them up with the following specific aims:Specific aim 1: to measure the effect of BZN 30d/150 mg compared to 60d/300 mg preconceptional treatment on parasitic load measured by the frequency of positive Polymerase Chain Reaction (PCR) (primary outcome) and by real-time quantitative PCR (qPCR), immediately and 10 months after treatment.Specific aim 2: to measure the frequency of serious adverse events and/or any adverse event leading to treatment interruption.Fil: Cafferata, María L.. Instituto de Efectividad Clínica y Sanitaria; Argentina. Unicem; UruguayFil: Toscani, María A.. Instituto de Efectividad Clínica y Sanitaria; ArgentinaFil: Althabe, Fernando. Organizacion Mundial de la Salud; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Centro de Investigaciones en Epidemiología y Salud Pública. Instituto de Efectividad Clínica y Sanitaria. Centro de Investigaciones en Epidemiología y Salud Pública; ArgentinaFil: Belizan, Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Centro de Investigaciones en Epidemiología y Salud Pública. Instituto de Efectividad Clínica y Sanitaria. Centro de Investigaciones en Epidemiología y Salud Pública; ArgentinaFil: Bergel, Eduardo. Instituto de Efectividad Clínica y Sanitaria; ArgentinaFil: Berrueta, Mabel. Instituto de Efectividad Clínica y Sanitaria; ArgentinaFil: Capparelli, Edmund V.. University of California; Estados UnidosFil: Ciganda, Álvaro. Instituto de Efectividad Clínica y Sanitaria; ArgentinaFil: Danesi, Emmaría. Dirección Nacional de Institutos de Investigación. Administración Nacional de Laboratorios e Institutos de Salud. Centro Nacional de Diagnóstico e Investigaciones Endemo-epidémicas; ArgentinaFil: Dumonteil, Eric. University of Tulane; Estados UnidosFil: Gibbons, Luz. Instituto de Efectividad Clínica y Sanitaria; ArgentinaFil: Gulayin, Pablo Elías. Instituto de Efectividad Clínica y Sanitaria; ArgentinaFil: Herrera, Claudia. University of Tulane; Estados UnidosFil: Momper, Jeremiah D.. University of California; Estados UnidosFil: Rossi, Steven. University of California; Estados UnidosFil: Shaffer, Jeffrey G.. University of Tulane; Estados UnidosFil: Schijman, Alejandro Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; ArgentinaFil: Sosa-Estani, Sergio Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Centro de Investigaciones en Epidemiología y Salud Pública. Instituto de Efectividad Clínica y Sanitaria. Centro de Investigaciones en Epidemiología y Salud Pública; ArgentinaFil: Stella, Candela B.. Instituto de Efectividad Clínica y Sanitaria; ArgentinaFil: Klein, Karen. Instituto de Efectividad Clínica y Sanitaria; ArgentinaFil: Buekens, Pierre. University of Tulane; Estados Unido
Search for eccentric black hole coalescences during the third observing run of LIGO and Virgo
Despite the growing number of confident binary black hole coalescences observed through gravitational waves so far, the astrophysical origin of these binaries remains uncertain. Orbital eccentricity is one of the clearest tracers of binary formation channels. Identifying binary eccentricity, however, remains challenging due to the limited availability of gravitational waveforms that include effects of eccentricity. Here, we present observational results for a waveform-independent search sensitive to eccentric black hole coalescences, covering the third observing run (O3) of the LIGO and Virgo detectors. We identified no new high-significance candidates beyond those that were already identified with searches focusing on quasi-circular binaries. We determine the sensitivity of our search to high-mass (total mass M>70 M⊙) binaries covering eccentricities up to 0.3 at 15 Hz orbital frequency, and use this to compare model predictions to search results. Assuming all detections are indeed quasi-circular, for our fiducial population model, we place an upper limit for the merger rate density of high-mass binaries with eccentricities 0<e≤0.3 at 0.33 Gpc−3 yr−1 at 90\% confidence level
Ultralight vector dark matter search using data from the KAGRA O3GK run
Among the various candidates for dark matter (DM), ultralight vector DM can be probed by laser interferometric gravitational wave detectors through the measurement of oscillating length changes in the arm cavities. In this context, KAGRA has a unique feature due to differing compositions of its mirrors, enhancing the signal of vector DM in the length change in the auxiliary channels. Here we present the result of a search for U(1)B−L gauge boson DM using the KAGRA data from auxiliary length channels during the first joint observation run together with GEO600. By applying our search pipeline, which takes into account the stochastic nature of ultralight DM, upper bounds on the coupling strength between the U(1)B−L gauge boson and ordinary matter are obtained for a range of DM masses. While our constraints are less stringent than those derived from previous experiments, this study demonstrates the applicability of our method to the lower-mass vector DM search, which is made difficult in this measurement by the short observation time compared to the auto-correlation time scale of DM
Long-time behavior for a nonlinear fourth-order parabolic equation
We study the asymptotic behavior of solutions of the initial- boundary value problem, with periodic boundary conditions, for a fourth-order nonlinear degenerate diffusion equation with a logarithmic nonlinearity. For strictly positive and suitably small initial data we show that a positive solution exponentially approaches its mean as time tends to infinity. These results are derived by analyzing the equation verified by the logarithm of the solution
Effect of Nb5 + content on the high temperature properties of the mixed conductors system La1 − xBaxCo1 − yNbyO3 − δ with 0.6 ≤ x ≤ 1.0 and 0 ≤ y ≤ 0.4
The replacement of Co by Nb in the La1 − xBaxCo1 − yNbyO3 − δ (0.6 ≤ x ≤ 1.0) system and its effects on phase stability and high temperature properties of the cubic perovskite phase were investigated by X-ray diffraction, dilatometry, electrical conductivity, oxygen permeation and electrochemical impedance spectroscopy. The incorporation of Nb in the B site stabilizes the cubic perovskite in the as prepared samples. The Nb solubility increases from y = 0.1, for the sample with Ba content x = 0.6, to y = 0.4 for 0.8 ≤ x ≤ 1.0. However, after a heat treatment at 750 °C during 10 days small amounts of secondary phases were detected for samples with x = 0.9 and 1.0. The linear expansion of the cubic phases decreases with the Nb content as well as with the Ba content. The minimum value, α = 12.9 × 10− 6 K− 1, was obtained for La0.2Ba0.8Co0.6Nb0.4O3 − δ. The behavior of electrical conductivity and oxygen permeation data with Nb content is explained from variations in the oxygen vacancy concentration, which is controlled by Nb5 + and Ba2 + contents. The minimum polarization resistance value, Rp = 0.08 Ω cm2, was obtained at 600 °C for La0.2Ba0.8Co0.9Nb0.1O3 − δ. The low Rp value of this compound and the crystal structure stability of various compositions in the system La1 − xBaxCo1 − yNbyO3 − δ with x ≥ 0.7 and y ≥ 0.1 make these materials of interest as mixed conductors.Fil: Setevich, C. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional del Sur. Departamento de Física; Argentina. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; ArgentinaFil: Toscani, Lucía María. Consejo Nacional de Investigaciones Científicas y Técnicas. Unidad de Investigación y Desarrollo Estratégico para la Defensa. Ministerio de Defensa. Unidad de Investigación y Desarrollo Estratégico para la Defensa; ArgentinaFil: Larrondo, Susana Adelina. Consejo Nacional de Investigaciones Científicas y Técnicas. Unidad de Investigación y Desarrollo Estratégico para la Defensa. Ministerio de Defensa. Unidad de Investigación y Desarrollo Estratégico para la Defensa; Argentina. Universidad Nacional de San Martín; ArgentinaFil: Prado, F.. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional del Sur. Departamento de Física; ArgentinaFil: Caneiro, A. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentin
Synthesis and characterization of mesoporous NiO2/ZrO2-CeO2 catalysts for total methane conversion
This work reports the synthesis and characterization of mesoporous NiO/ZrO2-CeO2 composites. These materials are still being developed due to their excellent morphological and structural properties, especially for solid oxide fuel cells (SOFCs) anodes. A soft chemical route using a polymeric template was utilized to synthesize the samples. The structure after two different calcination processes at 400 °C and 540 °C was studied by X-ray diffraction and Rietveld refinement, before and after NiO loading. Nitrogen adsorption, scanning/transmission electron microscopy and small angle X-ray scattering revealed a nanocrystalline bi-phasic porous material. Temperature programmed reduction experiments showed higher Ni and Ce reduction values for samples calcined at 400 °C and 540 °C, respectively. Methane conversion values in the temperature range studied were similar for both calcination temperatures, showing 50% CH4 conversion around 550 °C and 80% around 650 °C. However, a sample calcined at 400 °C exhibited better morphological and textural properties leading to an enhancement in NiO and CeO2 reducibility that might be responsible for an improvement in oxygen surface exchange and gasification of carbon species in catalytic experiments.Fil: Bacani, R.. Universidade de Sao Paulo; BrasilFil: Toscani, Lucía María. Consejo Nacional de Investigaciones Científicas y Técnicas. Unidad de Investigación y Desarrollo Estratégico para la Defensa. Ministerio de Defensa. Unidad de Investigación y Desarrollo Estratégico para la Defensa; ArgentinaFil: Martins, T. S.. Universidade Federal de Sao Paulo; BrasilFil: Fantini, M. C. A.. Universidade de Sao Paulo; BrasilFil: Lamas, Diego Germán. Universidad Nacional de San Martín. Escuela de Ciencia y Tecnología; Argentina. Comisión Nacional de Energía Atómica. Centro Atómico Constituyentes. Gerencia de Investigación y Aplicaciones; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Larrondo, Susana Adelina. Consejo Nacional de Investigaciones Científicas y Técnicas. Unidad de Investigación y Desarrollo Estratégico para la Defensa. Ministerio de Defensa. Unidad de Investigación y Desarrollo Estratégico para la Defensa; Argentina. Universidad Nacional de San Martín. Instituto de Investigación e Ingeniería Ambiental; Argentin
Effect of swelling agent in the synthesis of porous nanocrystalline nickel-zirconia-ceria composite
Porous ceria-zirconia (Zr0 · 1Ce0 · 9O2 − δδ delete) powders were synthesized by a sol-gel route using inorganic chlorides (ZrCl4 and CeCl3·7H2O) as precursors, block copolymer P123 (PEO20PPO70PEO20) as the template and tri-isopropyl-benzene (TIPB) as the swelling agent. These porous materials show high surface area and gas permeability, important properties for Intermediate Temperature-Solid Oxide Fuel Cell (IT-SOFC) and catalytic applications. The samples were prepared with different P123:TIPB (w/w) % ratios (1:0, 1:1, 1:2 and 1:4), as a strategy to increase porosity. The samples were calcined at 400 °C in air to remove the template. Post-synthesis nickel impregnation was planned to obtain 3 and 10 (w/w) % of NiO after calcination. The structure and morphology of the samples were determined by X-ray diffraction (XRD), small angle X-ray scattering (SAXS), nitrogen adsorption isotherms (NAI) and transmission and scanning electron microscopies (TEM and SEM). The resulting materials have high specific surface area (≈110 m2. g-1) and a wide pore size distribution of mesopores (3–50 nm). They are formed by nanocrystals (≈15 nm) of the predominant (≈90%) Fm3¯m cubic phase and by the P42/nmc tetragonal phase. The micrographs revealed that the nanocrystalline oxides have mesopores with slit shape and a secondary smaller mesoporosity with a narrow size distribution (≈4 nm). An increase of micropore volume (sizes < 2 nm) was observed with the presence of the swelling agent in the synthesis process, ideal for gas diffusion in catalysis and IT-SOFC processes. Temperature programmed reduction (TPR) analysis presented low temperature peaks, a marked increase in the total reduction value and H2 uptake of samples with 3 (w/w)% NiO in contrast to the bare supports. There was no significant further increase in the total reduction value when 10 (w/w)% NiO is incorporated. It is noteworthy that comparing the synthesis methods, all samples presented higher reduction values and H2 uptake.Fil: Cassimiro, V. R. S.. Universidade de Sao Paulo; BrasilFil: Monteiro, R. C.. Universidade de Sao Paulo; BrasilFil: Bacani, R.. Universidade de Sao Paulo; BrasilFil: Toscani, Lucía María. Consejo Nacional de Investigaciones Científicas y Técnicas. Unidad de Investigación y Desarrollo Estratégico para la Defensa. Ministerio de Defensa. Unidad de Investigación y Desarrollo Estratégico para la Defensa; ArgentinaFil: Lamas, Diego Germán. Universidad Nacional de San Martín. Escuela de Ciencia y Tecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Unidad Ejecutora Instituto de Nanociencia y Nanotecnología. Unidad Ejecutora Instituto de Nanociencia y Nanotecnología - Nodo Bariloche | Comisión Nacional de Energía Atómica. Unidad Ejecutora Instituto de Nanociencia y Nanotecnología. Unidad Ejecutora Instituto de Nanociencia y Nanotecnología - Nodo Bariloche; ArgentinaFil: Larrondo, Susana Adelina. Consejo Nacional de Investigaciones Científicas y Técnicas. Unidad de Investigación y Desarrollo Estratégico para la Defensa. Ministerio de Defensa. Unidad de Investigación y Desarrollo Estratégico para la Defensa; ArgentinaFil: Fantini, M. C. A.. Universidade de Sao Paulo; Brasi
A Chromo-Fluorogenic Synthetic “Canary” for CO Detection Based on a Pyrenylvinyl Ruthenium(II) Complex
The chromo-fluorogenic detection of carbon
monoxide in air has been achieved using a simple,
inexpensive system based on ruthenium(II). This probe
shows exceptional sensitivity and selectivity in its sensing
behavior in the solid state. A color response visible to the
naked eye is observed at 5 ppb of CO, and a remarkably
clear color change occurs from orange to yellow at the
onset of toxic CO concentrations (100 ppm) in air. Even
greater sensitivity (1 ppb) can be achieved through a
substantial increase in turn-on emission fluorescence in the
presence of carbon monoxide, both in air and in solution.
No response is observed with other gases including water
vapor. Immobilization of the probe on a cellulose strip
allows the system to be applied in its current form in a
simple optoelectronic device to give a numerical reading
and/or alarm.Financial support from the Spanish Government (project MAT2012-38429-C04) and the Generalitat Valenciana (project PROMETEO/2009/016) is gratefully acknowledged. M.E.M. is grateful to the Spanish Ministerio de Ciencia e Innovacion for an FPU grant. J.D.E.T.W.-E. and A.T. acknowledge the Leverhulme Trust for a grant (RPG-2012-634).Moragues Pons, ME.; Toscani, A.; Sancenón Galarza, F.; Martínez-Máñez, R.; White, A.; Wilton-Ely, JDET. (2014). A Chromo-Fluorogenic Synthetic Canary for CO Detection Based on a Pyrenylvinyl Ruthenium(II) Complex. Journal of the American Chemical Society. 136(34):11930-11933. https://doi.org/10.1021/ja507014a11930119331363