485 research outputs found

    Quantum Characterization of a Werner-like Mixture

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    We introduce a Werner-like mixture [R. F. Werner, Phys. Rev. A {\bf 40}, 4277 (1989)] by considering two correlated but different degrees of freedom, one with discrete variables and the other with continuous variables. We evaluate the mixedness of this state, and its degree of entanglement establishing its usefulness for quantum information processing like quantum teleportation. Then, we provide its tomographic characterization. Finally, we show how such a mixture can be generated and measured in a trapped system like one electron in a Penning trap.Comment: 8 pages ReVTeX, 8 eps figure

    Ultrasound Evaluation of Diaphragmatic Mobility and Contractility After Osteopathic Manipulative Techniques in Healthy Volunteers : A Prospective, Randomized, Double-Blinded Clinical Trial

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    Objective: The purpose of this study was to investigate the effect of a session of osteopathic manipulative techniques on diaphragmatic motion and thickness in healthy participants. Methods: This was a prospective, randomized, double-blinded, case vs sham vs control clinical trial performed in an outpatient osteopathic clinic in Rome, Italy. Sixty-seven healthy participants, mean age 40.4 \ub1 14.5 years, received an ultrasound evaluation of diaphragmatic motion and thickness, followed by a systematic osteopathic evaluation. After randomization, the experimental group (n = 22) received osteopathic manipulation, whereas the sham (n = 22) and the control (n = 22) groups had a light touch approach and simple observation, respectively. After a 1-session intervention, new osteopathic and ultrasound assessments were repeated in all participants. Results: A statistically significant increase in diaphragmatic mobility was observed in the experimental group after the osteopathic manipulation (\u394 = 14.5 mm, P < .001; analysis of variance P < .001 vs both sham: \u394 = -0.22 mm, and control: \u394 = -2.09 mm groups). A strong linear relationship was observed between the diaphragmatic motion gradient, measured with ultrasonography, and the score assigned by the operator evaluating the change of diaphragm mobility after intervention. Conclusion: Osteopathic techniques used in this study improved the diaphragmatic motion (but not the muscle thickness) in healthy participants. Further studies are needed to confirm our findings and eventually identify the clinical conditions that may benefit from osteopathic manipulative treatment of the diaphragm

    Controllability and universal three-qubit quantum computation with trapped electron states

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    We show how to control and perform universal three-qubit quantum computation with trapped electron quantum states. The three qubits are the electron spin, and the first two quantum states of the cyclotron and axial harmonic oscillators. We explicitly show how the universal gates can be performed. As an example of a non-trivial quantum algorithm, we outline the implementation of the Deutsch-Jozsa algorithm in this system.Comment: 4 pages, 1 figure. Typos corrected. The original publication is available at http://www.springerlink.co

    Characterization of CdTe with photoelectronic techniques

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    Thermally stimulated current (TSC) and space-charge limited current (SCLC) measurements have been performed in CdTe grown by Bridgman method with various In dopings and grown from Te-rich solution with Cl doping. Hole traps have been evidenced at 0.07, 0.14, 0.25 and 0.36 eV from valence band, while electron traps are at 0.05, 0.34, 0.52 and 0.62 eV from conduction band. Measurements of activation energies of resistivity vs temperature curves indicate which of these should correspond to donors or acceptors centers. Various methods of analysis were used both for TSC and for SCLC results, in order to determine the more suitable ones. Finally TSC and SCLC are compared and discussed as methods for CdTe characterization.Des mesures de courants thermostimulés ou limités par charge d'espace ont été employées pour caractériser des cristaux de tellurure de cadmium préparés soit par la méthode de Bridgman (avec différents niveaux de dopage à l'In) soit par le procédé THM sous solvant tellure (avec dopage au C1). Les pièges suivants ont été identifiés : pour les trous, des niveaux localisés à 0,07, 0,14, 0,25, 0,36 eV de la bande de valence, pour les électrons à 0,05, 0,34, 052 et 0,62 eV de la bande de conduction. A partir des mesures de résistivité en fonction de la température il a été possible de déterminer les niveaux donneurs et accepteurs, respectivement. L'analyse des courbes de courants thermostimulés et de charge d'espace a été effectuée de plusieurs façons, afin de déterminer les conditions optimales d'analyse. Finalement, les mérites respectifs de ces deux procédés de caractérisation seront discutés dans le cas où elles sont mises en œuvre sur CdTe

    In vitro antiatherogenicity of extracts from Halimeda incrassata seaweed: antioxidant activity and smooth muscle cell migration studies

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    Aim: The aim of this work was to evaluate the in vitro atheroprotective potential of the seaweed Halimeda incrassata in smooth muscle cell migration and lipoprotein oxidation in relation to its antioxidant activity. Material and methods: Antioxidant activity was determinate by DPPH• radical scavenging assay and ORAC method. The inhibitory effect of the aqueous extract on LDL oxidation mediated by Cu2+ ions was determinate by TBARS and conjugated diene quantification. The effect of the seaweed aqueous extract on smooth muscle cell migration was evaluated in MOVAS-1 mouse aortic smooth muscle cell. Results: The inhibitory effect of the aqueous extract on lipoprotein oxidation mediated by Cu2+ was demonstrated. Seaweed extract caused dose-dependent inhibition of TBARS (IC50 = 0.8 mg/mL) and conjugated dienes formation. The seaweed had a high antioxidant activity in the assays performed. The activity could be related to the phenolic content of Halimeda incrassata. Conclusions: In summary, the results of this study represent a further step in the characterization of the atheroprotective action of Halimeda incrassata and indicate the seaweed could be used for a nutraceutical and/or phytoterapeutic application.Objetivos: El objetivo de este trabajo fue evaluar el potencial ateroprotector in vitro del alga Halimeda incrassata en la migración de células de músculo liso de ratón y la oxidación de lipoproteínas en relación con su actividad antioxidante. Material y métodos: La actividad antioxidante fue determinada mediante los métodos de inhibición de radicales DPPH y la Capacidad antioxidante total (ORAC). La actividad inhibitoria de la oxidación de LDL mediada por iones Cu2+ se determinó por la cuantificación de TBARS y dienos conjugados. El efecto del extracto acuoso sobre la migración de las células de músculo liso se evaluó en la línea de células de músculo liso aórtica de ratón MOVAS-1. Resultados: Se demostró el efecto inhibidor del extracto sobre la oxidación de LDL mediada por Cu2+. El extracto del alga causa inhibición dosis-dependiente de la formación de TBARS (IC50 = 0,8 mg/mL) y dienos conjugados. Las algas tuvieron una alta actividad antioxidante en los ensayos realizados y podría estar relacionada con el contenido de compuestos fenólicos. Conclusiones: Los resultados de este trabajo representan un paso más en la caracterización de la acción ateroprotectora de Halimeda incrassata y evidencian sus posibles aplicaciones como nutracéutico y/o fitofármaco.The research was funded by IFS grant F/4897-1. Partial funding was also provided by CIHR grant MOP24447, the Canadian Research Chair award (D.B.) and a personal grant from GSEP, offered by the Canadian Bureau for International Education (A.C) and CNPq- (Brasil)

    Noise-assisted preparation of entangled atoms

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    We discuss the generation of entangled states of two two-level atoms inside an optical cavity. The cavity mode is supposed to be coupled to a white noise with adjustable intensity. We describe how the entanglement between the atoms inside the cavity arise in such a situation. The entanglement is maximized for intermediate values of the noise intensity, while it is a monotonic function of the spontaneous rate. This resembles the phenomenon of stochastic resonance and sheds more light on the idea to exploit white noise in quantum information processing.Comment: 4 pages, 4 figure

    Comparation of antioxidants properties and polyphenols content of aqueous extract from seaweeds Bryothamnion triquetrum and Halimeda opuntia

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    Objetivos. Evaluar y comparar las propiedades antioxidantes mediante ensayos in vitro de extractos acuosos de las algas roja Bryothamnion triquetrum y verde Halimeda opuntia y su relación con el contenido de polifenoles. Material y Métodos. Se utilizaron las técnicas in vitro: DPPH, Capacidad reductora, Inhibición de la peroxidación lipídica e inhibición de la hemólisis inducida por AAPH. Resultados. B. triquetrum: DPPH; CI50=1,15 ± 0,06, capacidad reductora a concentración; 128 mg/mL, DO=2,798, inhibición de la peroxidación lipídica; CI50=5,09± 0,25 e inhibición de la hemólisis con 12 mg/ mL; 35 %. H. opuntia: DPPH; CI50=12,34 ± 0,30 mg/mL, capacidad reductora; DO=0,800, inhibición de la peroxidación lipídica; CI50=1,25± 0,31 mg/mL e inhibición de la hemólisis; 82%. Conclusiones. Los resultados evidencian que B triquetrum resulto mucho más eficiente en los ensayos de DPPH y Capacidad reductora mientras H opuntia resulta más eficiente en Inhibición de la peroxidación lipídica e inhibición de la hemólisis. Se discuten algunos aspectos acerca de sus posibles mecanismos de acción.Objective. To evaluate and compare the antioxidant activity displayed by seaweed H. opuntia and B. triquetrum using different experimental in vitro antioxidant assessment models. Material and Methods. The following techniques are utilized: DPPH, Reducing power, inhibition of lipid peroxidation and inhibition of haemolysis. Results. B. triquetrum: DPPH; IC50=1.15 ± 0.06, Reducing power (concentration 128 mg/mL), OD=2.798, inhibition of lipid peroxidation; IC50=5.09± 0.25 and inhibition of haemolysis; with 12 mg/mL; 35 %. H. opuntia: DPPH; IC50=12.34 ± 0.30 mg/mL, reducing power; OD=0.800, inhibition of lipid peroxidation; IC50=1.25± 0.31 mg/mL, inhibition of lipid peroxidation; IC50=1.25± 0.31 mg/mL and inhibition of haemolysis; 82%. Conclusion. It was demonstrated that B.triquetrum extract was more effective than H. opuntia in reducing power and DPPH assays while H.opuntia was more effective in inhibition of lipid peroxidation in rat brain homogenates and the inhibition of red blood cell (RBC) haemolysis induced by AAPH. We discuss some aspects about their possible mechanisms of action.Este trabajo fue financiado parcialmente por CNPq (Brasil) a través del Proyecto No. 401852/2012-1

    Actividad antioxidante y polifenoles de las algas marinas halimeda opuntia y halimeda monile

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    En este trabajo se estudió la actividad antioxidante de dos especies de algas marinas (H. opuntia y H. monile) mediante el ensayo de atrapamiento de radicales DPPH• y el sistema β-Caroteno-acido linoleico. Adicionalmente a las fracciones de ácidos fenolicos libres, ésteres solubles y ésteres insolubles de ácidos fenólicos se les determinó el contenido en fenoles totales mediante la técnica de Folin-Ciocalteu y posteriormente se identificaron y cuantificaron 8 ácidos fenólicos y cinámicos, resultando el componente mayoritario el ácido salicílico. En los ensayos utilizados se obtuvieron valores altos de actividad antioxidante para las diferentes fracciones. A partir de estos resultados se puede postular que la actividad antioxidante de los extractos polares de estas algas pudiera ser explicada, al menos parcialmente, por la presencia de los ácidos fenólicos y cinámicos. En el caso del alga Halimeda monile, de acuerdo con la literatura consultada, es el primer reporte de la actividad antioxidante.In this paper, the antioxidant activity displayed by two different green seaweed species (H. opuntia y H. monile) was studied using the β- carotene/ linoleic acid and the DPPH• scavenging.systems as different experimental in vitro antioxidant assessment models. Polar seaweed fractions containing free phenolic acids, soluble esters and insoluble esters of phenolic acids were chemically characterized in terms of their phenolic content and composition. In that direction, 8 phenolic acids were identified and quantified, and salycilic acid was shown to be the majoritary compound on the fractions from both species. In addition, the polar fractions were proved to exert antioxidant activity in the two used experimental systems with considerably low values of CI50. Thus, in view of these findings, the antioxidant activity of these polar Halimeda spp. extracts could be supported and at least partially related to the presence of phenolic acids. In case of Halimeda monile this is, at least to the extend of our knowledge, the first report of such biological activity
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