2,134 research outputs found

    Magneto-optical characteristics of magnetic nanowire arrays in anodic aluminium oxide templates

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    Nanocomposite films consisting of regularly ordered iron nanowires embedded in anodic aluminum oxide templates have been fabricated and their magneto-optical properties studied by determining the four Stokes parameters of the transmitted laser beam (λ=670 nm), originally linearly polarized and at normal incidence to the film surfaces. The results of the nanowire arrays are found to be considerably different from that of bulk iron. While an increase in diameter of the nanowire leads to a substantial increase in the values of the Faraday rotation angles per unit length at a fixed value of the magnetic fields, they are substantially less than that of bulk iron, indicating that the effective media theory may not be directly applicable

    Resistive switching and threshold switching behaviors in La 0.1Bi 0.9Fe 1-xCo xO 3 ceramics

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    The effects of cobalt doping on the electrical conductivity of La 0.1Bi 0.9Fe 1-xCo xO 3 (LBFCO, x=0, 0.01, 0.03) ceramics were investigated. It is found that the leakage current increases with cobalt dopant concentration in LBFCO. On the application of bias voltage LBFCO ceramics with cobalt doping exhibits resistive switching effects at room temperature and threshold switching effects at elevated temperatures (50°C and 80°C). X-ray photoelectron spectroscopy of LBFCO ceramics show that cobalt dopant is bivalent as an acceptor, which induces an enhancement of oxygen vacancy concentration in LBFCO ceramics. Possible mechanisms for both resistive switching and threshold switching effects are discussed on the basis of the interplay of bound ferroelectric charges and mobile charged defects. © 2012 American Institute of Physics.published_or_final_versio

    On-line optimization of the operating configuration for urban high-voltage system

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    2003-2004 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

    Genes Underlying Positive Influence Of Prenatal Environmental Enrichment And Negative Influence Of Prenatal Earthquake Simulation And Corrective Influence Of Chinese Herbalmedicine On Rat Offspring: Irf7 And Ninj2

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    Background: Prenatal environmental enrichment (EE) has been proven to positively affect but prenatal stress negatively influence the physiological and psychological processes in animals, whose trans-generational genetic mechanism remains unclearly defined. We aimed to investigate and find out key genes underlying the positive-negative effects derived from prenatal interventions.Materials and Methods: Pregnant rats were randomized into EE group (EEG), earthquake simulation group (ESG), herbal group (HG) received herbal supplements in feed after earthquake simulation, and control group (CG).Results: Light Box Defecation Test (LBDT) showed EEG offspring presented less fecal pellets than CG offspring, ESG’s more than CG’s, and HG’s less than ESG (p’s<0.05). Open-field Test (OFT) score of EEG was higher than CG offspring, of ESG’s was lower than CG’s, and HG’s higher than ESG’s. Irf7 and Ninj were screened, which were up-regulated in EEG, down-regulated in ESG (FC<0.5), and were neutralized in HG. Prenatal EE could positively promote the nervous system development, prenatal earthquake simulation could retard the nervous system development and Chinese herbal remedy (JKSQW) which could correct the retardation.Conclusion: The negative-positive prenatal effect could contribute to altered gene expression of Irf7 and Ninj2 which also could play a key role in the improving function of JKSQWfor the kidneys.Keywords: Prenatal stress; Earthquake simulation; Light Box Defecation Test; Open-field Test; Irf7; Ninj

    Neural correlates of heterotopic facilitation induced after high frequency electrical stimulation of nociceptive pathways

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    <p>Abstract</p> <p>Background</p> <p>High frequency electrical stimulation (HFS) of primary nociceptive afferents in humans induce a heightened sensitivity in the surrounding non-stimulated skin area. Several studies suggest that this heterotopic effect is the result of central (spinal) plasticity. The aim of this study is to investigate HFS-induced central plasticity of sensory processing at the level of the brain using the electroencephalogram (EEG). To this end we measured evoked potentials in response to noxious electrical pinprick-like stimuli applied in the heterotopic skin area before, directly after and 30 minutes after HFS.</p> <p>Results</p> <p>We observed potential cortical electrophysiological correlates of heterotopic facilitation. Two different cortical correlates were found; the first one was a lateralized effect, i.e. a larger N100 amplitude on the conditioned arm than the control arm 30 minutes after end of HFS. This was comparable with the observed lateralized effect of visual analogue scale (VAS) scores as response to the mechanical punctate stimuli. The second correlate seems to be a more general (non-lateralized) effect, because the result affects both arms. On average for both arms the P200 amplitude increased significantly 30 minutes after end of HFS with respect to baseline.</p> <p>Conclusions</p> <p>We suggest that for studying heterotopic nociceptive facilitation the evoked brain response is suitable and relevant for investigating plasticity at the level of the brain and is perhaps a more sensitive and reliable marker than the perceived pain intensity (e.g. VAS).</p
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