6,680 research outputs found

    Field distribution of epidural electrical stimulation

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    Epidural electrical stimulation has been applied in clinics for many years. However, there is still a concern about possible injury to spinal nerves. This study investigated electrical field and current density distribution during direct epidural electrical stimulation. Field distribution models were theoretically deduced, while the distribution of potentials and current were analyzed. The current density presented an increase of 70-80%, with one peak value ranging from -85 degrees to 85 degrees between the two stimulated poles. The effect of direct epidural electrical stimulation is mainly on local tissue surrounding the electrodes, concentrated around the two stimulated positions.postprin

    A dynamic prediction model for intraoperative somatosensory evoked potential monitoring

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    This study proposed a support vector regression model applied in prediction of intraoperative somatosensory evoked potential changes associated with physiological and anesthetic changes. This model was developed from probability distribution and support vector machines. The predicted results showed that observed and predicted SEP has similar variation trend with different values, with acceptable errors. With this prediction model, changes of SEP in correlation with non-surgical factors were estimated. Not only the prediction accuracy of SEP has been improved, but also provides the reliability of the classification. It will be helpful to develop an intelligent monitor model based expert system that can make a reliable decision for the potential spinal injury.published_or_final_versio

    Frequency instability in Er/Yb fiber grating lasers due to heating by nonradiative transitions

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    Author name used in this publication: Demokan, M. S.Version of RecordPublishe

    Narrowband Single-Pole Double-Throw Filtering Switch Based on Dielectric Resonator

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    © 2001-2012 IEEE. In this letter, a narrowband single-pole double-throw (SPDT) filtering switch based on dielectric resonators (DRs) is presented. It consists of two DRs shared by two channels for size reduction. Printed circuit boards are embedded in the metal cavity to integrate the PIN diodes. The switching between two channels is enabled by controlling the PIN diodes connected to the two output feeding lines. The electromagnetic field distributions of the DR at the TE -{11\delta } mode are studied to control the coupling between the DR and two output feeding lines. When one channel is on, the PIN diode for this channel is turned off, which does not introduce loss and affect the linearity. For the off-state channel, isolation is obtained by controlling the coupling between the DR and output feeding line, which is considerably enhanced. For demonstration, the DR filtering SPDT switch is implemented. The measured results exhibit that the proposed filtering SPDT switch has narrow bandwidth, low loss, high isolation, and high linearity

    Low-loss narrowband filtering switch based on coaxial resonators

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    © 2013 IEEE. In this paper, a narrowband filtering switch with low loss and high selectivity is presented based on coaxial resonators for the first time. PIN diodes mounted on the printed circuit boards are embedded into a coaxial filter to enable ON and OFF states. In the ON-state, the PIN diodes are turned OFF, which do not introduce the loss and affect the linearity. Two transmission zeros are generated by a novel feeding structure, which improves the skirt selectivity. In the OFF-state, the PIN diodes are turned on. Then, lumped capacitors are loaded to the coaxial resonators so that the resonant frequencies of the resonators are changed. The passband at the operating frequency cannot be formed, resulting in high isolation. For demonstration, the coaxial-resonator-based filtering switch is designed and fabricated. Good agreement between simulated and measured results verifies the proposed ideas. Comparison with other reported filtering switches is given. The proposed filtering switch shows the advantages of high Q-factor, relatively compact size, and wide stopband responses, which is attractive in wireless systems

    Excitation Spectra And Hard-core Thermodynamics Of Bosonic Atoms In Optical Superlattices

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    A generalized double-well-basis coupled representation is proposed to investigate excitation spectra and thermodynamics of bosonic atoms in double-well optical superlattices. In the hard-core limit and with a filling factor of one, excitations describing the creation of pairs of a doubly occupied state and a simultaneous empty state, and those from a symmetric singly occupied state to an antisymmetric state are carefully analyzed and their excitation spectra are calculated within mean-field theory. Based on the hard-core statistics, the equilibrium properties such as heat capacity and particle populations are studied in detail. The cases with other filling factors are also briefly discussed.published_or_final_versio

    Development and application of a loop-mediated isothermal amplification method for rapid detection of Haemophilus parasuis

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    Haemophilus parasuis is the causative agent of Glässer’s disease that has received much attention recently, due to the increasing economic losses this disease inflicts upon the pig industry worldwide. In this study, loop-mediated isothermal amplification method (LAMP) methodology was designed for diagnosing H. parasuis infections and tested against 56 clinical samples. Two sets of primers for LAMP were designed based on the H. parasuis inf B gene sequence. Target DNA was amplified and visualized on agarose gels after 50 min incubation at 63°C. The LAMP amplicon was also directly visualized in the reaction tubes by the naked eye following the addition of SYBR green I. The detection limit of the inf BLAMP method was 10 cfu mL-1, that was 10 times more sensitive than conventional PCR. Furthermore, positive rates of H. parasuis detection using inf B-LAMP were higher (46.4%, 26/56) than the rates obtained with conventional PCR (33.9%, 19/56). inf B-LAMP specificity analysis demonstrated no crossreactivity with any other swine pathogens. In conclusion, inf B-LAMP was more sensitive and faster and could be carried out in the absence of expensive equipment. Furthermore, the visual readout demonstrated great potential for the use of inf B-LAMP in the clinical detection of H. parasuis.Key words: Glässer’s disease, Haemophilus parasuis, inf B, PCR, LAM

    The HI Bias during the Epoch of Reionization

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    The neutral hydrogen (HI) and its 21 cm line are promising probes to the reionization process of the intergalactic medium (IGM). To use this probe effectively, it is imperative to have a good understanding on how the neutral hydrogen traces the underlying matter distribution. Here we study this problem using semi-numerical modeling by combining the HI in the IGM and the HI from halos during the epoch of reionization (EoR), and investigate the evolution and the scale-dependence of the neutral fraction bias as well as the 21 cm line bias. We find that the neutral fraction bias on large scales is negative during reionization, and its absolute value on large scales increases during the early stage of reionization and then decreases during the late stage. During the late stage of reionization, there is a transition scale at which the HI bias transits from negative on large scales to positive on small scales, and this scale increases as the reionization proceeds to the end.Comment: 11 pages, 11 figures, MNRAS accepte
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