9 research outputs found

    Adaptive RF Pigtail Probe Modeling for De-embedding of RF Measurements

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    This disclosure describes techniques for accurate estimation and de-embedding of the effects of pigtail probes in circuits. An adaptive pigtail model is developed and described that can accurately de-embed the effects of pigtail probes in digital circuits. Example parameters are identified that include pigtail length, tip length, pigtail tilt degree, ground distance, and solder amount. A pigtail simulation model is developed to model the soldered pigtail probe. The dependency of circuit impedance on the identified parameters is determined by experimentation which indicates that circuit performance can be boosted by short ground distance lengths, low tilt angles, thick support wires, short pin and cable lengths, and thick support wires. The pigtail model can be utilized to derive de-embedded results for different pigtail probe configurations without a need for explicitly measuring de-embedded results for those configurations

    Decay Constants of Pseudoscalar DD-mesons in Lattice QCD with Domain-Wall Fermion

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    We present the first study of the masses and decay constants of the pseudoscalar D D mesons in two flavors lattice QCD with domain-wall fermion. The gauge ensembles are generated on the 243×4824^3 \times 48 lattice with the extent Ns=16 N_s = 16 in the fifth dimension, and the plaquette gauge action at β=6.10 \beta = 6.10 , for three sea-quark masses with corresponding pion masses in the range 260−475260-475 MeV. We compute the point-to-point quark propagators, and measure the time-correlation functions of the pseudoscalar and vector mesons. The inverse lattice spacing is determined by the Wilson flow, while the strange and the charm quark masses by the masses of the vector mesons ϕ(1020) \phi(1020) and J/ψ(3097) J/\psi(3097) respectively. Using heavy meson chiral perturbation theory (HMChPT) to extrapolate to the physical pion mass, we obtain fD=202.3(2.2)(2.6) f_D = 202.3(2.2)(2.6) MeV and fDs=258.7(1.1)(2.9) f_{D_s} = 258.7(1.1)(2.9) MeV.Comment: 15 pages, 3 figures. v2: the statistics of ensemble (A) with m_sea = 0.005 has been increased, more details on the systematic error, to appear in Phys. Lett.

    Interoceptive awareness: MBSR training alters information processing of salience network

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    Mindfulness refers to a mental state of awareness of internal experience without judgment. Studies have suggested that each mindfulness practice may involve a unique mental state, but the underlying neurophysiological mechanisms remain unknown. Here we examined how distinct mindfulness practices after mindfulness-based intervention alter brain functionality. Specifically, we investigated the functional alterations of the salience network (SN) using functional magnetic resonance imaging (fMRI) among the two interoceptive mindfulness practices—breathing and body scan—associated with interoceptive awareness in fixed attention and shifted attention, respectively. Long-distance functional connectivity (FC) and regional homogeneity (ReHo) approaches were applied to measure distant and local neural information processing across various mental states. We hypothesized that mindful breathing and body scan would yield a unique information processing pattern in terms of long-range and local functional connectivity (FC). A total of 18 meditation-naïve participants were enrolled in an 8-week mindfulness-based stress reduction (MBSR) program alongside a waitlist control group (n = 14), with both groups undergoing multiple fMRI sessions during breathing, body scan and resting state for comparison. We demonstrated that two mindfulness practices affect both the long-distance FCSN and the local ReHo, only apparent after the MBSR program. Three functional distinctions between the mindfulness practices and the resting state are noted: (1) distant SN connectivity to occipital regions increased during the breathing practice (fixed attention), whereas the SN increased connection with the frontal/central gyri during the body scan (shifting attention); (2) local ReHo increased only in the parietal lobe during the body scan (shifting attention); (3) distant and local connections turned into a positive correlation only during the mindfulness practices after the MBSR training, indicating a global enhancement of the SN information processing during mindfulness practices. Though with limited sample size, the functional specificity of mindfulness practices offers a potential research direction on neuroimaging of mindfulness, awaiting further studies for verification

    Somatic pain associated with initiation of interferon-alpha (IFN-α) plus ribavirin (RBV) therapy in chronic HCV patients: A prospective study

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    Objective: This study is aimed to investigate the association between interferon-alpha (IFN-α) plus ribavirin (RBV) treatment and emergence of somatic pain symptoms in patients with hepatitis C virus (HCV) over a 24-week treatment. Method: In this prospective cohort study, 297 patients with HCV were evaluated at baseline and 2nd, 4th, 8th, 12th, 16th, 20th, and 24th week with structured Mini-International Neuropsychiatric Interview for Major Depressive Disorder (MDD) diagnosis and the Neurotoxicity Rating Scale (NRS) for somatic symptoms. Results: Eighty-seven out of the 297 patients (29%) developed IFN-α induced depression and had significantly higher somatic pain symptoms as early as the 2nd week and at all the assessment time points (p ​< ​.001). Most depressed patients perceived greatest somatic pain at the 8th week of treatment. Moreover, NRS somatic pain scores after initial therapy strongly correlated with NRS somatic pain scores at all other assessment time points (p ​< ​.001). Conclusion: IFN-α therapy induce significant somatic pain as early as the 2nd week of treatment in HCV patients who later developed MDD. Thus, initial NRS somatic pain score after initiation of IFN-α treatment may serve as a reference for the susceptibility of the individual to IFN-α induced depression

    Data_Sheet_1_Interoceptive awareness: MBSR training alters information processing of salience network.PDF

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    Mindfulness refers to a mental state of awareness of internal experience without judgment. Studies have suggested that each mindfulness practice may involve a unique mental state, but the underlying neurophysiological mechanisms remain unknown. Here we examined how distinct mindfulness practices after mindfulness-based intervention alter brain functionality. Specifically, we investigated the functional alterations of the salience network (SN) using functional magnetic resonance imaging (fMRI) among the two interoceptive mindfulness practices—breathing and body scan—associated with interoceptive awareness in fixed attention and shifted attention, respectively. Long-distance functional connectivity (FC) and regional homogeneity (ReHo) approaches were applied to measure distant and local neural information processing across various mental states. We hypothesized that mindful breathing and body scan would yield a unique information processing pattern in terms of long-range and local functional connectivity (FC). A total of 18 meditation-naïve participants were enrolled in an 8-week mindfulness-based stress reduction (MBSR) program alongside a waitlist control group (n = 14), with both groups undergoing multiple fMRI sessions during breathing, body scan and resting state for comparison. We demonstrated that two mindfulness practices affect both the long-distance FCSN and the local ReHo, only apparent after the MBSR program. Three functional distinctions between the mindfulness practices and the resting state are noted: (1) distant SN connectivity to occipital regions increased during the breathing practice (fixed attention), whereas the SN increased connection with the frontal/central gyri during the body scan (shifting attention); (2) local ReHo increased only in the parietal lobe during the body scan (shifting attention); (3) distant and local connections turned into a positive correlation only during the mindfulness practices after the MBSR training, indicating a global enhancement of the SN information processing during mindfulness practices. Though with limited sample size, the functional specificity of mindfulness practices offers a potential research direction on neuroimaging of mindfulness, awaiting further studies for verification.</p
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