150 research outputs found

    Quercetin and Bornyl Acetate Regulate T-Lymphocyte Subsets and INF-γ/IL-4 Ratio In Utero in Pregnant Mice

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    The objective of this study is to investigate the antiabortive effects of Quercetin and Bornvl Acetate and their immunological modulation at maternal-fetal interface. Lipopolysaccharide (LPS) was injected via tail vein to induce abortion in mice which received Quercetin and Bornvl Acetate at days 4–7 of gestation. Uterine CD4+/CD8+ T lymphocytes and IFN-γ/IL-4 of each group (n = 10) were detected by immunohistochemistry and enzyme-linked immunosorbent assay, respectively. The ratio of CD4+/CD8+ increased significantly (P < .01) in the uterus of LPS-induced abortion mice. In the Quercetin and Bornvl Acetate pretreated mice followed by LPS administration, the ratio of CD4+/CD8+ dropped to 0.562 ± 0.021, lower than that of LPS-abortion group (P < .01). The mean value of IFN-γ/IL-4 in LPS-treated mice was 0.310 ± 0.066, higher than that of Quercetin and Bornyl Acetate group. The results indicate that Quercetin and Bornyl Acetate have an antiabortive effect through modulation of immunological balance at maternal-fetal interface

    ADJUVANT EFFECTS OF SIJUNZI DECOCTION IN CHICKENS ORALLY VACCINATED WITH ATTENUATED NEWCASTLE-DISEASE VACCINE

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    Many Chinese Herbal medicines (CHMs) and their components have been reported to enhance immunity. In this study, the capacity for the Chinese herbal medicine, oral administration Sijunzi Decoction (SJZD) in stimulating Newcastle disease virus(NDV) immunity in chickens was examined. Serum was sampled on days 20,30,40,50 and 60 and tissues were collected on days 20, 40 and 60, respectively. The immune responses were determined by means of hemagglutination inhibition test, immunohistochemistry examination and semi-quantitative RT–PCR. The results showed that SJZD could increase the antibody titers and the area coefficient of IgA secreting cells, promote the expression of IL-2 mRNA in the whole immune period and IFN-γ mRNA was increased in the initial stage. The SJZD used was safe with no adverse effects on chicken weight or survival, providing evidence for the use of SJZD as an oral adjuvant

    Interactions between inertial particles and shocklets in compressible turbulent flow

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    Numerical simulations are conducted to investigate the dynamics of inertial particles being passively convected in a compressible homogeneous turbulence. Heavy and light particles exhibit very different types of non-uniform distributions due to their different behaviors near shocklets. Because of the relaxation nature of the Stokes drag, the heavy particles are decelerated mainly at downstream adjacent to the shocklets and form high-number-density clouds. The light particles are strongly decelerated by the added-mass effect and stay in the compression region for a relatively long time period. They cluster into thin filament structures near shocklets

    MIL-53(Fe) derived magnetic CuFe2O4/Fe2O3 composite for catalytic oxidation of sulfamethoxazole via peroxymonsulfate activation

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    Design of metal–organic framework (MOF) derived metal oxides is an effective approach for environmental remediation. The current study describes the fabrication of MIL-53-derived perforated CuFe2O4/Fe2O3 using a facile, one-step, post-thermal solid-state approach by varying Cu/Fe ratios. Herein, the release of CO2 and H2O during the thermal treatment facilitates the incorporation of Cu2+ onto the Fe2O3 structure, forming a perforated hollow CuFe2O4/Fe2O3 composite via an in-situ ion-exchange mechanism. The optimised catalyst CF-0.5 displays a high degradation efficiency for the removal of sulfamethoxazole (SMX) by heterogeneous activation of peroxymonsulfate (PMS), ascribing to the better textural, morphological, and elemental properties of the novel catalyst. Important reaction parameters such as pH, catalyst loading, PMS dosage, pollutant kind and concentration, and reaction temperature are further optimised to develop a cost-effective catalytic system. The magnetically recoverable catalyst outlines a high stability rate, and only a 9 % efficiency loss is observed even after the fourth cycle. Reactive oxygen species (ROS) are identified by electron paramagnetic resonance spectroscopy (EPR) and their roles are determined by performing quenching experiments. In the end, a detailed study of the mineralisation ability and reaction intermediates is performed and possible pathways for the degradation mechanism are proposed. This study not only introduces a facile approach for the fabrication of MOF-driven nanomaterials but provides insights into the removal of emerging contaminants such as SMX

    Experimental study on mechanical and acoustic emission characteristics of sedimentary sandstone under different loading rates

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    In the field of rock engineering, complexity of stress environment is an important factor affecting its stability. Thus, in view of fracture mechanism of rock under different loading rates within the scope of quasi-static strain rate, four groups of uniaxial compression tests with different strain rates were carried out on sandstone specimens, and strength, deformation, failure modes and acoustic emission characteristics of specimens were compared and analyzed. Furthermore, the fracture mechanism was discussed from the perspective of fracture characteristics based on fractal dimension, crack propagation law inverted through acoustic emission b-value, and micro fracture morphology. The results showed that as the strain rate increased from 10 to 5 s−1 to 10−2 s−1, the fractal dimension of rock fragments increased, and the fractal dimension of rock fragments increased by 9.66%, 7.32%, and 3.77% successively for every 10 times increase in strain rate, which means that the equivalent size of fragments was getting smaller, and the fragmentation feature was becoming increasingly prominent. The crack propagation process based on acoustic emission b-value showed that with the increase of loading rate, the specimen entered the rapid crack propagation stage earlier, in order of 68%, 66%, 29%, and 22% of peak stress. Moreover, the microscopic fracture morphology showed that with the increase of loading rate, transgranular phenomenon was clear, and the fracture morphology changed from smooth to rough. That meant that the fracture of sandstone rock at high loading rates was mainly caused by the propagation of large cracks, which was different from the slow process of initiation, convergence and re-propagation of small cracks at low strain rates

    Improved SnO2 Electron Transport Layers Solution-Deposited at Near Room Temperature for Rigid or Flexible Perovskite Solar Cells with High Efficiencies

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    Electron transport layer (ETL) is a functional layer of great significance for boosting the power conversion efficiency (PCE) of perovskite solar cells (PSCs). To date, it is still a challenge to simultaneously reduce the surface defects and improve the crystallinity in ETLs during their low-temperature processing. Here, a novel strategy for the mediation of in situ regrowth of SnO2 nanocrystal ETLs is reported: introduction of controlled trace amounts of surface absorbed water on the fluorinated tin oxide (FTO) or indium-tin oxide (ITO) surfaces of the substrates using ultraviolet ozone (UVO) pretreatment. The optimum amount of adsorbed water plays a key role in balancing the hydrolysis-condensation reactions during the structural evolution of SnO2 thin films. This new approach results in a full-coverage SnO2 ETL with a desirable morphology and crystallinity for superior optical and electrical properties, as compared to the control SnO2 ETL without the UVO pretreatment. Finally, the rigid and flexible PSC devices based on the new SnO2 ETLs yield high PCEs of up to 20.5% and 17.5%, respectively

    A new fault diagnosis and fault-tolerant control method for mechanical and aeronautical systems with neural estimators

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    A new method of fault detection and fault tolerant control is proposed in this paper for mechanical systems and aeronautical systems. The faults to be estimated and diagnosed are malfunctions occurred within the control loops of the systems, rather than some static faults, such as gearbox fault, component cracks, etc. In the proposed method two neural networks are used as on-line estimators, the fault will be accurately estimated when the estimators are adapted on-line with the post fault dynamic information. Furthermore, the estimated value of faults are used to compensate for the impact of the faults, so that the stability and performance of the system with the faults are maintained until the faulty components to be repaired. The sliding mode control is used to maintain system stability under the post fault dynamics. The control law and the neural network learning algorithms are derived using the Lyapunov method, so that the neural estimators are guaranteed to converge to the fault to be diagnosed, while the entire closed-loop system stability is guaranteed with all variables bounded. The main contribution of this paper to the knowledge in this field is that the proposed method cannot only diagnose and tolerant with constant fault, also diagnose and tolerant with the time-varying faults. This is very important because most faults occurred in industrial systems are time-varying in nature. A simulation example is used to demonstrate the design procedure and the effectiveness of the method. The simulation results are compared with two existing methods that can cope with constant faults only, and the superiority is demonstrated

    Laboratory Calibration of D-dot Sensor Based on System Identification Method

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    D-dot sensors can realize the non-contact measurement of transient electric fields, which is widely applied to electromagnetic pulse (EMP) measurements with characteristics of the wide frequency band, high linearity, and good stability. In order to achieve accurate calibration of D-dot sensors in the laboratory environment, this paper proposed a new calibration method based on system identification. Firstly, the D-dot sensor can be considered as a linear time-invariant (LTI) system under corner frequency, thus its frequency response can be characterized by the transfer function of a discrete output error (OE) model. Secondly, based on the partial linear regression of the transfer function curve, the sensitivity coefficient of the D-dot sensor is obtained. By increasing the influence weight of low-frequency components, this proposed method has better calibration performance when the waveform is distorted in the time domain, and can artificially adapt to the operating frequency range of the sensor at the same time
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