Search

In order to reduce the axial force of the semi-open centrifugal pump with low specific speed, the influencing factors of the axial force of the semi-open centrifugal pump are analyzed and studied by means of orthogonal experiment by combining numerical analysis. The blade tip clearance and balance hole diameter are selected as experimental factors, and each factor takes 5 levels to carry out orthogonal design. SST k-ω Turbulence equation is used to calculate the axial force of the semi-open centrifugal pump. According to the comparison between the calculated results and the experimental results of the original model, it is found that the head and efficiency change within 5%, so the numerical simulation method is feasible. Based on L25 (5²) orthogonal table, 25 groups of experimental schemes are designed, and the optimal scheme is obtained by analyzing the numerical simulation results of 25 groups of experimental schemes. The results show that by reducing the tip clearance and establishing the balance hole, the back cavity pressure increases significantly, and the axial force of the centrifugal pump decreases greatly, the maximum reduction is 440.59 N, accounting for 45.6% of the total axial force of the original model. At the same time, it has little effect on pump performance, efficiency only reduces by 3.76%, and the head reduces by only 0.3%. [ABSTRACT FROM AUTHOR]

Background: Accumulating evidence implicates the neuroendocrine immunomodulation (NIM) network in the physiopathological mechanism of Alzheimer's disease (AD). Notably, we previously revealed that the NIM network is dysregulated in the PrP-hAβPPswe/PS1 ΔE9 (APP/PS1) transgenic mouse model of AD., Methods: After treatment with a novel Liuwei Dihuang formula (LW-AFC), mice were cognitively evaluated in behavioral experiments. Neuron loss, amyloid-β (Aβ) deposition, and Aβ level were analyzed using Nissl staining, immunofluorescence, and an AlphaLISA assay, respectively. Multiplex bead analysis, a radioimmunoassay, immunochemiluminometry, and an enzyme-linked immunosorbent assay (ELISA) were used to measure cytokine and hormone levels. Lymphocyte subsets were detected using flow cytometry. Data between two groups were compared using a Student's t test. Comparison of the data from multiple groups against one group was performed using a one-way analysis of variance (ANOVA) followed by a Dunnett's post hoc test or a two-way repeated-measures analysis of variance with a Tukey multiple comparisons test., Results: LW-AFC ameliorated the cognitive impairment observed in APP/PS1 mice, including the impairment of object recognition memory, spatial learning and memory, and active and passive avoidance. In addition, LW-AFC alleviated the neuron loss in the hippocampus, suppressed Aβ deposition in the brain, and reduced the concentration of Aβ 1-42 in the hippocampus and plasma of APP/PS1 mice. LW-AFC treatment also significantly decreased the secretion of corticotropin-releasing hormone and gonadotropin-releasing hormone in the hypothalamus, and adrenocorticotropic hormone, luteinizing hormone, and follicle-stimulating hormone in the pituitary. Moreover, LW-AFC increased CD8 + CD28 + T cells, and reduced CD4 + CD25 + Foxp3 + T cells in the spleen lymphocytes, downregulated interleukin (IL)-1β, IL-2, IL-6, IL-23, granulocyte-macrophage colony stimulating factor, and tumor necrosis factor-α and -β, and upregulated IL-4 and granulocyte colony stimulating factor in the plasma of APP/PS1 mice., Conclusions: LW-AFC ameliorated the behavioral and pathological deterioration of APP/PS1 transgenic mice via the restoration of the NIM network to a greater extent than either memantine or donepezil, which supports the use of LW-AFC as a potential agent for AD therapy.