26 research outputs found

    Untargeted Metabolomics Reveals the Protective Effect of Fufang Zhenshu Tiaozhi (FTZ) on Aging-Induced Osteoporosis in Mice

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    Fufang Zhenzhu Tiaozhi (FTZ), as an effective traditional Chinese medicine, has been prescribed for more than 20 years. It has proven clinical efficacy as a prescription for patients with dyslipidemia, glucocorticoid- and high-fat-induced osteoporosis, but its effect on osteoporosis induced by aging is still unclear. The aim of this study was to investigate the anti-osteoporosis effect of FTZ in aging mice and revealed its biochemical action mechanism using metabolomics. Model of primary osteoporosis induced by aging was established. The mice in treatment group received a therapeutic dose of oral FTZ extract once daily during the experiment. The model and control groups received the corresponding volume of oral normal saline solution. Plasma samples of all three groups were collected after 12 weeks. Clinical biochemical parameters and biomechanics were determined in the osteoporosis model induced by normal aging to evaluate anti-osteoporosis effect of FTZ. Ultra performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-QTOF/MS) was used to analyze metabolic changes. The changes of histomorphometric and biomechanic parameters of femurs, as well as osteoblast and osteoclast activity indicated that FTZ administration reduced the risk of osteoporosis. Partial least squares discriminant analysis (PLS-DA) score plot revealed a clear separation trend between model and controls. Moreover, PLS-DA score plot indicated the anti-osteoporosis effect of FTZ with sphingosine 1-phosphate, LPA (16:0) and arachidonic acid (AA) among key biomarkers. The pivotal pathways revealed by pathway analysis including sphingolipid metabolism, glycerophospholipid metabolism, and AA metabolism. The mechanism by which FTZ reduces the risk of primary age-related osteoporosis in mice might be related to disorders of the above-mentioned pathways. FTZ has a protective effect against osteoporosis induced by aging, which may be mediated via interference with sphingolipid, glycerophospholipid, and AA metabolisms in mice

    Effect of Pore Defects on Mechanical Properties of Graphene Reinforced Aluminum Nanocomposites

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    Pore defects have an important effect on the mechanical properties of graphene reinforced aluminum nanocomposites. The simulation study found that the pores affect the stress distribution in the matrix of the composite. Along the stretching direction, the larger stress appears on both sides of the pore, which is the source of potential cracks. It results in a sharp decrease in the mechanical properties of the composite. The higher the porosity, the greater the tendency of pore aggregation, and the risk of material failure is higher. The stress distribution in the matrix becomes more uneven as the pore size increases, and the large strain area around the pores also increases. Composites with circular pores have a higher strength than other irregularly shaped pores. The failure mode might be pore cracking, while composites with other shape pores are more prone to interface detachment. The simulation value of the stress-strain of the composite material is in good agreement with the experimental value, but the finite element simulation value is larger than the experimental value

    Dynamic Behavior of Rotation Transmission Nano-System in Helium Environment: A Molecular Dynamics Study

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    The molecular dynamics (MD) method is used to investigate the influence of the shielding gas on the dynamic behavior of the heterogeneous rotation transmission nano-system (RTS) built on carbon nanotubes (CNTs) and boron nitride nanotube (BNNT) in a helium environment. In the heterogeneous RTS, the inner CNT acts as a rotor, the middle BNNT serves as a motor, and the outer CNT functions as a stator. The rotor will be actuated to rotate by the motor due to the interlayer van der Waals effects and the end effects. The MD simulation results show that, when the gas density is lower than a critical range, a stable signal of the rotor will arise on the output and the rotation transmission ratio (RRT) of RTS can reach 1.0, but as the gas density is higher than the critical range, the output signal of the rotor cannot be stable due to the sharp drop of the RRT caused by the large friction between helium and the RTS. The greater the motor input signal of RTS, the lower the critical working helium density range. The results also show that the system temperature and gas density are the two main factors affecting the RTS transmission behavior regardless of the size of the simulation box. Our MD results clearly indicate that in the working temperature range of the RTS from 100 K to 600 K, the higher the temperature and the lower the motor input rotation frequency, the higher the critical working helium density range allows

    Analysis of fracture behavior of thin polycrystalline diamond films

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    The effect of the substrate temperature and CH4 concentrations on the fracture behavior of thin polycrystalline diamond films was systematically investigated by X-ray diffraction and scanning electron microscopy. The results show that the fracture behavior of thin polycrystalline diamond films synthesized by direct current plasma jet chemical vapor deposition is closely related to the substrate temperature and CH4 concentrations. A high substrate temperature, due to difference in the thermal expansion coefficients of the substrate and the diamond film, causes thin polycrystalline diamond films to generate high residual stresses, which usually exceed fracture strength of thin diamond film and even that of diamond. The fracture toughness is found to drop with the increasing ratio of CH4 concentration. In case of high CH4 concentrations, various defects and impurities, such as cracks, microscopic holes, graphite, and amorphous carbon were observed in the films. Thus, the substrate temperature and CH 4 concentrations should be strictly controlled within an appropriate rang

    A Fast Interface Circuit for the Measurement of 10 Ω to 1 GΩ Resistance

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    In this work, an interface circuit applied to resistive gas or chemical sensors is proposed. The interface circuit includes a detection front-end, a single-end to differential circuit, a successive approximation analog-to-digital converter (SAR ADC), and some reference auxiliary circuits. In detection front-end circuits, mirrored currents in a current mirror usually differ by several orders of magnitude. In order to ensure that the current mirror can be copied accurately, this work uses a negative feedback structure consisting of an operational amplifier and an NMOS tube to ensure that the VDS of the current mirroring tube remains consistent. Simulation results show that the replication error of the current mirror is 0.015%. The proposed interface circuit has a detection range of 10 Ω to 1 GΩ with a relative error of 0.55%. The current multiplication or divided technique allows the interface circuit to have a high sampling frequency of up to 10 kHz. The proposed circuit is based on a 180 nm CMOS process with a chip area of 0.308 mm2 (723 μm ∗ 426 μm). The power consumption of the whole interface circuit is 3.66 mW when the power supply voltage is 1.8 V

    The Microstructure and Thermal Conductivity of Pressureless Infiltrated SiCp/Al Composites Containing Electroless Nickel Platings

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    A nickel (Ni) coating was deposited on the surface of silicon carbide particles (SiCp) through electroless plating and we characterized the morphology and phase structure of the coating and the pressureless infiltrated SiCp/Al composites. The effect of Ni coatings on the thermal conductivity of the composites was examined and analyzed with three-dimensional video microscope, scanning electron microscope (SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction microscope (XRD), and finite-element. The results show that a continuous and uniform coating with a certain thickness (around 3.5 μm) can be formed on the surface of SiCp. With the addition of the Ni layer, there are some intermetallics Ni3Al but no interfacial carbide Al4C3, which improves the wettability and the thermal conductivity of the composites. The experiments and simulations both show that Ni coatings do not substantially decrease the overall thermal conductivity of the composite, although the thermal conductivity of Ni itself is lower than Al and SiC by a factor of 1

    Study on the Corrosion Characteristics of Grounding Materials in Acid Red Soil

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    The corrosion of grounding materials seriously threatens the safe operation of the power system. The corrosion resistance of four typical grounding materials as carbon steel, galvanized steel, Zn–Al-coated steel, copper was studied in acid red soil. The results show that carbon steel, galvanized steel, Zn–Al-coated steel, copper exhibit different corrosion resistance behaviors, respectively. The corrosion rate of these grounding materials usually increases first and then slowly decreases. Pitting corrosion is the main corrosion feature of carbon steel. The corrosion rate of carbon steel is the largest compared to the other three grounding materials. The corrosion rate of galvanized steel is higher than that of copper. Copper has a low corrosion rate and exhibits good corrosion resistance, but the cost of copper is high and it causes heavy metal pollution. The corrosion rate of Zn–Al-coated steel is the lowest compared to the other three grounding materials, and it has the best corrosion resistance
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