342 research outputs found

    Modeling and Simulation of Working Characteristics of Lithium Titanate Batteries for Emergency Power Transmission

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    This paper presents a battery model applied to dynamic simulation software. The simulation model uses only the battery State-Of-Charge (SOC) as a state variable in order to avoid the algebraic loop problem. It is shown that this model, composed of a controlled voltage source in series with a resistance, can accurately describe the lithium titanate battery discharge process. The model’s parameters can be easily extracted from the manufacturer’s discharge curve. In this paper, it is actually applied to the self-starting system after the emergency stop of the EMU, the simulation model of the system is established by MATLAB/Simulink, and the ground test platform is used to simulate the actual working condition of EMU to complete the experimental verification. The results of both simulation and experiment proved that the scheme of battery self-shifting driven system is feasible and correct

    Disrupting the Interaction between Retinoblastoma Protein and Raf-1 Leads to Defects in Progenitor Cell Proliferation and Survival during Early Inner Ear Development

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    The retinoblastoma protein (pRb) is required for cell-cycle exit of embryonic mammalian hair cells but is not required for hair cell fate determination and early differentiation, and this provides a strategy for hair cell regeneration by manipulating the pRb pathway. To reveal the mechanism of pRb functional modification in the inner ear, we compared the effects of attenuated pRb phosphorylation by an inhibitor of the Mitogen-Activated Protein (MAP) kinase pathway and an inhibitor of the Rb–Raf-1 interaction on cultured chicken otocysts. We demonstrated that the activity of pRb is correlated with its phosphorylation state, which is regulated by a newly established cell cycle-independent pathway mediated by the physical interaction between Raf-1 and pRb. The phosphorylation of pRb plays an important role during the early stage of inner ear development, and attenuated phosphorylation in progenitor cells leads to cell cycle arrest and increased apoptosis along with a global down-regulation of the genes involved in cell cycle progression. Our study provides novel routes to modulate pRb function for hair cell regeneration

    Wireless Power Transfer for Miniature Implantable Biomedical Devices

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    Miniature implantable electronic devices play increasing roles in modern medicine. In order to implement these devices successfully, the wireless power transfer (WPT) technology is often utilized because it provides an alternative to the battery as the energy source; reduces the size of implant substantially; allows the implant to be placed in a restricted space within the body; reduces both medical cost and chances of complications; and eliminates repeated surgeries for battery replacements. In this work, we present our recent studies on WPT for miniature implants. First, a new implantable coil with a double helix winding is developed which adapts to tubularly shaped organs within the human body, such as blood vessels and nerves. This coil can be made in the planar form and then wrapped around the tubular organ, greatly simplifying the surgical procedure for device implantation. Second, in order to support a variety of experiments (e.g., drug evaluation) using a rodent animal model, we present a special WPT transceiver system with a relatively large power transmitter and a miniature implantable power receiver. We present a multi-coil design that allows steady power transfer from the floor of an animal cage to the bodies of a group of free-moving laboratory rodents

    Relationship Between Dairy Products Intake and Risk of Endometriosis: A Systematic Review and Dose-Response Meta-Analysis

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    Objective: Diet lifestyle can influence the risk of endometriosis. Therefore, we conducted a systematicmeta-analysis to investigate the association between dairy products and the risk of endometriosis. Besides, we performed a dose-responsemeta-analysis to evaluate the amount of dairy intake affecting the risk of endometriosis. Methods: Relevant studies were searched from Pubmed, Embase databases, Cochrane Library, and Web of Science from the inception to November 6th, 2020. Also, the dose-response meta-analysis was conducted. All the pooled results were performed by risk ratios (RRs). Results: Finally, seven high-quality studies were included in the present meta-analysis. Total dairy intake was inversely associated with the risk of endometriosis, and the risk of endometriosis tended to decrease with a decrease in the risk of endometriosis when dairy products intake was over 21 servings/week (RR 0.87, 95% CI 0.76–1.00; pnon−linearity = 0.04). Similarly, people who consumed more than 18 servings of high-fat dairy products per week had a reduced risk of endometriosis (RR 0.86, 95% CI 0.76–0.96). When stratified-analyses were conducted based on specific dairy product categories, it indicated that people with high cheese intake might have a reduced risk of endometriosis (RR 0.86, 95%CI 0.74–1.00). Other specific dairy products such as whole milk (RR 0.90, 95% CI 0.72–1.12), reduced-fat/skim milk (RR 0.83, 95% CI 0.50–1.73), ice cream (RR 0.83, 95% CI 0.50–1.73), and yogurt (RR 0.83, 95% CI 0.62–1.11) have not shown significant evidence of an association with the risk of endometriosis. However, there is a higher risk of endometriosis in the females with high butter intake compared to females with low butter intake (1.27, 95% CI 1.03–1.55). Conclusions: Overall, dairy products intake was associated with a reduction in endometriosis, with significant effects when the average daily intake 3 servings. When analyzed according to the specific type of dairy product, it was shown that females with higher high-fat dairy and cheese intake might have a reduced risk of endometriosis. However, high butter intake might be associated to the increased risk of endometriosis. More future studies are needed to validate and add to this finding

    Transformable DNA nanocarriers for plasma membrane targeted delivery of cytokine

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    Direct delivery of cytokines using nanocarriers holds great promise for cancer therapy. However, the nanometric scale of the vehicles made them susceptible to size-dependent endocytosis, reducing the plasma membrane-associated apoptosis signalling. Herein, we report a tumor microenvironment-responsive and transformable nanocarrier for cell membrane targeted delivery of cytokine. This formulation is comprised of a phospholipase A2 (PLA2) degradable liposome as a shell, and complementary DNA nanostructures (designated as nanoclews) decorated with cytokines as the cores. Utilizing the tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) as a model cytokine, we demonstrate that the TRAIL loaded DNA nanoclews are capable of transforming into nanofibers after PLA2 activation. The nanofibers with micro-scaled lengths efficiently present the loaded TRAIL to death receptors on the cancer cell membrane and amplified the apoptotic signalling with reduced TRAIL internalization

    Investigation on Laser-induced Breakdown Spectroscopy of Potassium Chloride Solution

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    peer reviewedThe experimental setup for laser—induced breakdown spectroscopy test was designed with pulsed Nd:YAG laser,spectrograph and ICCD and so on.Furthermore the potassium chloride solution spectra signals were detected by this setup.The spectra lines of the trace elements such as natrium (20mg/1),magnesium(1 mg/1),calcium(3 mg/1)are recorded.Experiment results show that delay time is one of the important parameters when qualitative analysis.It is easy for LIBS technology to detect multi—elements simultaneity if delay time is appropriate,and qualitative analysis has demonstrated that the feasibility of detecting trace poisonous metals in waste water using LIBS

    Formation-maintaining control strategy for InSAR satellite

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    The control accuracy of distributed interferometric synthetic aperture radar satellite formation configuration maintenance is one of the key factors affecting the baseline length and thus the elevation measurement accuracy. According to the description and analysis of the relative orbital elements of formation dynamics, an unbiased four-pulse formation maintenance control method with independent in-plane and out-of-plane control is optimized and designed based on the traditional pulse control scheme. In particular, the coupling influence between relative orbital roots in the control process is compensated by combining with engineering practice, also the corresponding control strategy is formulated. The method has been applied to TH-2 system, and the correctness of the method has been proved by ground simulation and in-orbit data, so as to effectively ensure the expected distribution of interference baseline and provide guarantee for the smooth development of land elevation survey task
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