1,363 research outputs found

    Research on dynamic characteristics of spiral basilar membrane after replacing artificial auditory ossicle based on the reconstructed human ear model

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    In this paper, PATRAN software was used to establish a complete 3D finite element model of human ears, and it was then combined with NASTRAN software to analyze frequency responses. This paper conducted a detailed analysis on the dynamic parameters including umbo and stapes displacements of normal human ears under sound pressures 90 dB and 105 dB. The numerically computational results were compared with experimental data. When the analyzed frequency was less than 1000 Hz, the computational result of numerical simulation was well consistent with the upper limit. When the analyzed frequency was more than 1000 Hz, the computational result of numerical simulation was well consistent with the lower limit. Therefore, the numerically computational model was reliable. In addition, based on the verified model, this paper studied vibration characteristics of spiral basilar membrane after replacing artificial auditory ossicle based on the whole hearing system, and found that vibration characteristics of spiral basilar membrane had an obvious change at low and high frequencies after replacing artificial auditory ossicle TORP. Using finite element method to analyze vibration characteristics of spiral basilar membrane can well predict the hearing recovery effect after replacing artificial auditory ossicle. Compared with normal ears, the vibration level of spiral basilar membrane after replacing artificial auditory ossicle has slowed down in 100 Hz-600 Hz, 2000 Hz-4000 Hz and 7000 Hz-10000 Hz, and has been strengthened in 600 Hz-2000 Hz and 4000 Hz-7000 Hz, which provided some help for the hearing recovery at the high-frequency band

    Anti-thrombotic and anti-tumor effect of water extract of caulis of Sargentodoxa cuneata (Oliv) Rehd et Wils (Lardizabalaceae) in animal models

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    Purpose: To investigate the anti-thrombosis and anti-tumor effect of the water extract of the caulis of Sargentodoxa cuneata (Oliv.) Rehd. et Wils. (WCSW) in rat and mouse models.Methods: WCSW extract was prepared and the main constituents were determined by high pressure liquid chromatography (HPLC). The acute toxicity of the extract was determined in mice. Platelet aggregation in rat platelet-rich plasma (PRP) was examined to evaluate the effect of the extract on platelet function. Thereafter, the cytotoxic activity of WCSW on HL60, A549, S180 and H22 cells was determined by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. In vivo antitumor effect of WCSW was further evaluated on H22 cells transplanted in mice, while the expression of caspase-3, caspase-9, Bcl-2 and Bax proteins were assayed by Western blot analysis.Results: Protocatechuic acid, rhodiola glucoside and chlorogenic acid were identified as the main constituents of WCSW. Platelet aggregation was significantly inhibited by treatment with the extract at concentrations of 1, 5 and 10 mg/mL. WCSW also showed significant inhibitory effect on HL60, A549, S180 and H22 cells in vitro with half maximal inhibitory concentration (IC50 value of 321.9, 285.0, 130.3 and 76.1 μg/mL, respectively. Furthermore, WCSW exhibited obvious anti-tumor effect on H22 transplanted tumor in vivo. After treatment with WCSW, caspase-3, caspase-9 and Bax were significantly (p < 0.05) up-regulated, whereas Bcl-2 was significantly (p < 0.05) down-regulated in the tumor tissues.Conclusion: WCSW possesses significant antithrombosis and anti-tumor effect, and therefore, has the potentials to be developed into effective drugs for clinical treatment of cancer and thrombosis diseases.Keywords: Sargentodoxa cuneata, Anti-thrombosis, Anti-tumor, Platelet aggregation, Apoptosis, Caspase, Protocatechuic acid, Rhodiola glucoside, Chlorogenic aci

    Electrochemical behavior of lansoprazole at a multiwalled carbon nanotubes-ionic liquid modified glassy carbon electrode and its electrochemical determination

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    The electrochemical behavior of lansoprazole (LNS) has been investigated at a glassy carbon electrode (GCE) and the electrode modified by a gel containing multiwalled carbon nanotubes (MWCNTs) and an room-temperature ionic liquid (RTIL) of 1-Butyl-3-methylimidazolium hexafluorophosphate (BMIMPF6) in 0.10 M phosphate buffer solution of pH 6.8. It was found that an irreversible anodic oxidation peak with Epa as 1.060 V appeared at MWCNTs-RTIL/GCE. Under the optimized experimental conditions a linear calibration curve were obtained over the concentration range from 5.0 μM to 0.20 mM by differential pulse voltammetry with the limit of detection (LOD, S/N = 3) as 0.28 μM. In addition, the novel MWCNTs-RTIL/GCE was also characterized by the electrochemical impedance spectroscopy and the proposed method has been successfully applied in the electrochemical quantitative determination of LNS content in commercial tablet samples and the determination results could meet the determination requirement

    MUlti-Store Tracker (MUSTer): a Cognitive Psychology Inspired Approach to Object Tracking

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    International audienceVariations in the appearance of a tracked object, such as changes in geometry/photometry, camera viewpoint, illumination , or partial occlusion, pose a major challenge to object tracking. Here, we adopt cognitive psychology principles to design a flexible representation that can adapt to changes in object appearance during tracking. Inspired by the well-known Atkinson-Shiffrin Memory Model, we propose MUlti-Store Tracker (MUSTer), a dual-component approach consisting of short-and long-term memory stores to process target appearance memories. A powerful and efficient Integrated Correlation Filter (ICF) is employed in the short-term store for short-term tracking. The integrated long-term component, which is based on keypoint matching-tracking and RANSAC estimation, can interact with the long-term memory and provide additional information for output control. MUSTer was extensively evaluated on the CVPR2013 Online Object Tracking Benchmark (OOTB) and ALOV++ datasets. The experimental results demonstrated the superior performance of MUSTer in comparison with other state-of-art trackers

    A Redox-Sensitive Luciferase Assay for Determining the Localization and Topology of Endoplasmic Reticulum Proteins

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    Correct localization and transmembrane topology are crucial for the proteins residing and functioning in the endoplasmic reticulum (ER). We have developed a rapid and convenient assay, based on the redox-sensitive luciferase from Gaussia princeps (Gluc) and green fluorescence protein (GFP), to determine the localization or topology of ER proteins. Using the tandem Gluc-GFP reporter fused to different positions of a target protein, we successfully characterized the topologies of two ER transmembrane proteins Herp and HRD1 that are involved in the ER quality control system. This assay method may also be applicable to the proteins in secretory pathway, plasma membrane, and other compartments of cells
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