To study the evolution principle of the coherent structure in the low flow rate runaway condition, the pump-turbine of the certain pumped storage power plant is employed. The transient dynamic stress of the runner has been numerically simulated and examined in this study, in order that can probe the mechanism of channel vortices acting on the blade and the evolution of their coherent structure in the runner. Based on the Realizable k-ε turbulent model, the unsteady flow of the whole pump-turbine channels is calculated. Results show that the flow in the runner channels presents with the turbulence state, and with many different scales vortices. These vortices structures are mainly distributed in the inlet region of the blade, the area of the blade trailing edge and the middle section of the runner channels. These vortex structures affect the distribution of the blade pressure load. Moreover, vortices structure at the inlet of the runner depends on the change of the attack angle. In the flow region formed at the outlet of the blade near the suction surface and the runner cone, the blade has a limited effect to the fluid, thus the vortex structure depends on the Coriolis force and the centrifugal force joint action.

Background Previous studies have shown that depression was associated with HTR3B gene. The aim of this study was to investigate the relationship between polymorphisms of the HTR3B gene and depression and its executive dysfunction in Chinese Han population. Methods A total of 229 patients with depressive disorder and 202 healthy controls were enrolled. Six Single nucleotide polymorphism sites (SNPs) including rs10789970, rs4938056, rs12421126, rs1176744, rs2276305 and rs12795805 were genotyped by Snapshot. Clinical features were collected using a general demographic questionnaire. The 24-item Hamilton Depression Scale (HAMD) was used to assess the symptoms’ severity of the patients. The patients' executive function was assessed using a series of cognitive tests including Maze Test, Symbolic Coding Test, Spatial Span Inverse Order Test, Linking Test, and Emotional Management Test. Results The genotypic and allelic distributions of rs1176744 in HTR3B gene were significantly different (χ2 = 11.129, P = 0.004, χ2 = 9.288, P = 0.002, respectively) between patients and controls. The A allele was positively correlated with depression. The proportion of A carriers was significantly higher and that of C carriers was lower in patients than those in controls. Patients had significantly lower scores of Spatial Span Inverse Order Test in carriers of A allele at locus rs1176744 and higher scores in carriers of C alleles at locus rs1176744 and rs12795805. Conclusions The polymorphisms of HTR3B gene may be associated with depression in Chinese Han population. The A allele of rs1176744 may increase the risk of developing depression and executive dysfunction while C alleles of rs1176744 and rs12795805 may be the protective factors for executive dysfunction in patients with depression.

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