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A dramatic isotope effect in the reaction of ClSiH with trimethylsilane-1-d: experimental evidence for intermediate complexes in silylene Si-H(D) insertion reactions
A kinetic isotope effect (kD/kH) of 7.4 has been found for the reaction of chlorosilylene with trimethysilane (Me3SiD vs Me3SiH). Such a value can be accounted for by theoretical modelling, but only if an internal rearrangement of the initially form complex is included in the mechanism. This provides the first concrete evidence for such complexes
Correlated photon pairs generated from a warm atomic ensemble
We present measurements of the cross-correlation function of photon pairs at
780 nm and 1367 nm, generated in a hot rubidium vapor cell. The temporal
character of the biphoton is determined by the dispersive properties of the
medium where the pair generation takes place. We show that short correlation
times occur for optically thick samples, which can be understood in terms of
off-resonant pair generation. By modifying the linear response of the sample,
we produce near-resonant photon pairs, which could in principle be used for
entanglement distribution
Non-degenerate four-wave mixing in rubidium vapor: transient regime
We investigate the transient response of the generated light from Four-Wave
Mixing (FWM) in the diamond configuration using a step-down field excitation.
The transients show fast decay times and oscillations that depend on the
detunings and intensities of the fields. A simplified model taking into account
the thermal motion of the atoms, propagation, absorption and dispersion effects
shows qualitative agreement with the experimental observations with the energy
levels in rubidium (5S1/2, 5P1/2, 5P3/2 and 6S1/2). The atomic polarization
comes from all the contributions of different velocity classes of atoms in the
ensemble modifying dramatically the total transient behavior of the light from
FWM.Comment: 11 pages, 11 figures, to be published in Physical Review
Tasa de éxito subjetivo y objetivo en pacientes operados con cinta suburetral transobturatriz: ocho años de seguimiento
Indexación: Scopus; Scielo.Antecedentes: La Incontinencia Urinaria de Esfuerzo (IOE) representa el 50% de las incontinencias urinarias en la mujer, produciendo un gran impacto en su calidad de vida. Actualmente el TOT es una de las técnicas quirúrgicas más utilizadas para su tratamiento. Objetivos: Determinar la tasa de éxito objetiva y subjetiva de las pacientes operadas por IOE e incontinencia de orina mixta (IOM) mediante TOT, y determinar la tasa de complicaciones perioperatorias.
Métodos: Se realizó un estudio retrospectivo de cohorte de 8 años de seguimiento, en el que se evaluó mediante anamnesis, examen físico y protocolos quirúrgicos la tasa de éxito objetivo y subjetivo del TOT.
Resultados: La tasa de éxito objetivo y subjetivo fue 92% y 76% respectivamente. El 8,3% de las pacientes presentó alguna complicación y la tasa de exposición de malla fue de 1,2%.
Conclusiones: El TOT es una excelente alternativa para el tratamiento de la IOE en el Hospital de Quilpué.http://ref.scielo.org/6tnxn
Specific heat amplitude ratios for anisotropic Lifshitz critical behaviors
We determine the specific heat amplitude ratio near a -axial Lifshitz
point and show its universal character. Using a recent renormalization group
picture along with new field-theoretical -expansion techniques,
we established this amplitude ratio at one-loop order. We estimate the
numerical value of this amplitude ratio for and . The result is in
very good agreement with its experimental measurement on the magnetic material
. It is shown that in the limit it trivially reduces to the
Ising-like amplitude ratio.Comment: 8 pages, RevTex, accepted as a Brief Report in Physical Review
Antibacterial activity of a combination of cysteine and ciprofloxacin and its relationship with the generation of oxidative stress in extended-spectrum betalactamase-producing escherichia coli strains
The aim of the present work was to evaluate whether L-cysteine enhances theantibiotic susceptibility of extended-spectrum beta-lactamase (ESBL) Escherichia coli strains to ciprofloxacin and to identify the role of Reactive oxygen species (ROS) in the antimicrobial activity.The combined ef5fect of L-cysteine and ciprofloxacin was investigated by the macrodilution broth method and chemiluminescence assay. ESBL 1 and ESBL 2 strains presented a growth inhibition when they were incubated with 0.4 or 0.2 mM of cysteine, respectively compared to the control without antibiotic. Both strains at sub-inhibitory concentration of ciprofloxacin were combined withcysteine, and a clear growth inhibition respect to the control was observed. An increase of 68% in ROS occurred respect to the control when ESBL 1 was treated with a combination of ciprofloxacin and cysteine, while for ESBL 2 there was a rice of 127 %. The combination of ciprofloxacin with cysteine had the capacity to undergo redox cycling and ROS production with subsequent cellularinjury.Fil: Martínez, S. R.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Bongiovanni, M. E.. Hospital Privado Centro Medico de Córdoba; ArgentinaFil: Piersigilli, Andrea Laura. Sanatorio Aconcagua; ArgentinaFil: Albesa, Inés. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Departamento de Farmacia; ArgentinaFil: Becerra, María Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Departamento de Farmacia; Argentin
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