Search

Error analysis of inertial navigation systems is one of the important tasks in inertial navigation research. Through error analysis, the contribution of each error in the system to the total error can be obtained. This work is particularly important in the rotary modulation inertial navigation system, because it is necessary to evaluate the suppression effect of the rotation strategy on various error sources through error analysis. Firstly, a state space model of the error has been established based on the system error model, and the total navigation error is divided into linear combinations of various error factors through recursion and decomposition. The derived covariance update equation can be used to quickly and accurately obtain the contribution of various errors including initial error and device error to the total system error. Simulation results of strapdown, single-axis and two-axis modulation systems verifies that the error propagation rules calculated by the proposed method are in agreement with the known conclusions. Simulation of different modulation strategies shows that the proposed method is fast and intuitive in evaluating rotation strategies.

Based on a large amount of energy consumption, performance indicators and base station configuration data that can be collected in the 5G network management system, this paper uses machine learning algorithms to establish an energy consumption calculation model for common AAU equipment on the existing network, and verifies the accuracy of the model. The test results show that the accuracy of the energy consumption calculation models established by this scheme for several common AAU devices in the existing network has reached more than 97%, which fully proves that the energy consumption modeling method has high practicability and promotion value.

The large-acceleration motion of HFV (hypersonic flight vehicle), the high-speed rolling of spinning missile, and the large-maneuver flight of fighter aircraft has put forward higher performance demand for SINS (strapdown inertial navigation system). The high-accuracy positing will be realized under the high-dynamic maneuver environment after decreasing measurement error of IMU (inertial measurement unit), meanwhile the algorithm of SINS must be improved. The conventional algorithm calculates the flight attitude with determining the compensation term of coning error, after ignoring the high-order term of the Bortz equation. To improve the algorithm accuracy of SINS under high-dynamic maneuver environment, a high-accuracy algorithm, which uses Legendre polynomial to complete angular velocity function approximation and takes the numerical method of quaternion differential equation as core, is proposed herein. The high-order coning error is compensated in the numerical solving period in the proposed novel algorithm, because no approximation exists in deducing process. The attitude calculating simulations are finished in coning motion condition and high-dynamic maneuver condition respectively. Compared with the quadruple-cross-product compensation algorithm which has the highest accuracy at present, the attitude error of proposed algorithm is less than its 1/3 in coning motion condition. And algorithm accuracy is raised an order of magnitude under the high-dynamic maneuver environment. The high-accuracy algorithm based on Legendre polynomial has reference significance for accurate positing of future HFV, atomic gyroscope INS research and high-accuracy algorithm design of SINS.

In view of problem of low efficiency of bi-directional full-bridge DC-DC converter based on traditional single phase-shift control, the paper proposed a design scheme of bi-directional full-bridge DC-DC converter based on single phase-shift close-loop control. It analyzed steady characteristics of the bi-directional full-bridge DC-DC converter and detailedly introduced modeling implementation of the bi-directional full-bridge DC-DC converter based on single phase-shift close-loop control. The simulation and experiment results show that the converter has high efficiency and low loss.

Objective: To investigate whether or not NADPH oxidase (NOX) participates in Aspergillus fumigatus induced macrophage autophagy in RAW264.7 cells and explore the possible mechanism., Methods: RAW264.7 cells in the exponential growth phase were randomized into three groups: Aspergillus fumigatus conidia (MOI 5:1) treated group, Aspergillus fumigatus conidia plus NOX inhibitor diphenyleneiodonium chloride (DPI) treated group; negative control group (untreated). The levels of intracellular reactive oxygen species (ROS) were measured with dichiorodihydrofluorescein diacetate (DCFH-DA) staining by fluorescence microscope. The expression of microtubule-associated protein light chain-3 (LC3) protein in RAW264.7 cells was detected by Western blotting. Then the expression and positioning of LC-3 were observed by immunofluorescence staining., Results: After stimulated with conidia of Aspergillus fumigatus, RAW264.7 cells showed significant increases of ROS and LC3BII. Interestingly, LC3 was recruited to phagosomes which contained Aspergillus fumigatus conidia. After the NOX inhibitor DPI blocked the ROS production, the expressions of ROS and LC3BII had no significant increases as compared with the negative control group, and the distribution of LC3 was diffuse in cytoplasm., Conclusion: NOX induces macrophage autophagy by producing ROS in Aspergillus fumigatus infection.

Objective: To explore the effect of microtubule-associated protein light chain 3- lipoprotein antigen precursor (pCMV-LC3-LpqH) as an DNA adjuvant on the immunoprotection of the anti-tuberculosis DNA vaccine encoding Ag85B antigen from Mycobacterium tuberculosis (MTB)., Methods: BALB/c mice were randomly divided into four groups that were immunized three times with pCMV-Ag85B, pCMV-LpqH/pCMV-Ag85B, pCMV-LC3-LpqH/pCMV-Ag85B and pCMV, respectively. Two weeks after the final vaccination, the titers and subtypes of anti-Ag85B IgG of BALB/c mice were detected by ELISA. In vitro, the levels of interleukin 2 (IL-2), interferon γ (IFN-γ), IL-4 and IL-10 that were secreted from Ag85B-stimulated splenocytes were also measured by ELISA. Three months after the final vaccination, mice were challenged with virulent MTB H37Rv strain through the tail veins. The mice spleens and lungs were dissected out for counting colony-forming unit (CFU) and observing pulmonary histopathological changes after MTB infection., Results: LC3-LpqH/Ag85B-immunized mice showed the significant increase of IgG2a, IL-2 and IFN-γ, along with the decrease of IgG1, IL-4 and IL-10, lower MTB CFU in the spleens and lungs and a marked relief in pulmonary injury., Conclusion: LC3-LpqH could enhance Ag85B-specific Th1 immune response that exerts a superior immune protection, which might be a new practical strategy for developing MTB vaccines.

Objective: To construct an autophagy-targeted vaccine harboring the genes encoding Ag85B and microtubule-associated protein light chain-3 (LC3) and to explore its immunoprotection against Mycobacterium tuberculosis (MTB)., Methods: The pCMV-LC3-Ag85B plasmid was constructed and used to transfect RAW264.7 cells. The level of LC3-Ag85B was detected using Western blotting. Then, BALB/c mice were immunized with pCMV, pCMV-Ag85B and pCMV-LC3-Ag85B plasmid, respectively. In vitro, two weeks after the last immunization, the secretion of IL-2, IFN-γ, IL-4 and IL-10 from Ag85B-stimulated lymphocytes was measured by ELISA. Three months after the last immunization, all mice were challenged with MTB H37Rv via the tail vein and the bacterial loads in their spleens and lungs were determined by colony formation assay., Results: The LC3-Ag85B fusion protein was expressed in RAW264.7 cells that had been transfected with pCMV-LC3-Ag85B and the expression level was in a dose-dependent manner. Compared with the pCMV-Ag85B treatment group, pCMV-LC3-Ag85B-immunized mice showed a significant increase of IL-2 and IFN-γ levels and the lower loads of MTB in the spleens and lungs., Conclusion: pCMV-LC3-Ag85B can enhance a specific Th1-predominant immunity and a superior immunoprotection against MTB, which may provide a new practical strategy for the development of improved vaccines against MTB.

Objective: To construct an autophagy-targeted vaccine harboring the genes encoding lipoprotein antigen precursor LpqH from Mycobacterium tuberculosis and microtubule-associated protein light chain-3(LC3), and to investigate its efficacy of inducing and targeting autophagy., Methods: The expressions of LC-3 and LC3-LpqH in RAW264.7 cells were detected by Western blotting after transfected with pCMV-LpqH and pCMV-LC3-LpqH plasmids respectively. The pCMV-LC3-LpqH or pCMV-LpqH plasmids were transfected into GFP-LC3-RAW264.7 cells to analyze the localization of LC3-LpqH by immunofluorescence staining., Results: After transfected with pCMV-LpqH DNA, RAW264.7 cells showed a significant increase of LC-3 amount. The LC3-LpqH fusion protein was also detected in RAW264.7 cells after pCMV-LC3-LpqH transfection and in a dose-dependent manner. Interestingly, LpqH was found to be transported to autophagosomes through the fusion protein, which was demonstrated by the co-localization of GFP-LC3 and LC3-LpqH on autophagosomes., Conclusion: The recombinant plasmid encoding pCMV-LC3-LpqH could enhance the autophagy in vitro, and facilitate the localization of LpqH on autophagosomes. Our study provides a new practical strategy for the development of improved vaccines against Mycobacterium tuberculosis.

Objective: To study the changes of CD4(+);CD25(+);CD127(low); regulatory T cells (Tregs) and transforming growth factor beta 1 (TGF-β1) mRNA in peripheral blood mononuclear cells (PBMCs) in drug addicts during natural drug withdrawal, and explore the effects of addictive drugs on their Tregs., Methods: Peripheral blood was collected from 40 drug addicts with 6-month natural withdrawal, 40 cases with 18-month natural withdrawal and 30 healthy controls. Then the Tregs were counted by flow cytometry and TGF-β1 mRNA expression in PBMCs was detected by RT-PCR., Results: Compared with the controls, Tregs and TGF-β1 mRNA expression in PBMCs increased significantly in the group with one 18-month natural withdrawal, but no significant difference was found in the group with 6-month natural withdrawal., Conclusion: Addictive drugs have a long-term effect on the Tregs in drug addicts, and the abnormal Tregs may result in the immune dysfunction in drug addicts.