Background: Insulin-like growth factor-1 (IGF-1) has been demonstrated to increase fatty acid β oxidation during fasting, and play an important role in regulating lipid metabolism and type 2 diabetes mellitus (T2DM). The rs35767 (T > C) polymorphism, a functional SNP was found in IGF-1 promoter, which may directly affect IGF-1 expression. However, the inconsistent findings showed on the IGF-1 rs35767 polymorphism and T2DM risk.Methods: We performed a comprehensive meta-analysis to estimate the association between the IGF-1 rs35767 and T2DM risk among four genetic models (the allele, additive, recessive and dominant models).Results: A total 49,587 T2DM cases and 97,906 NDM controls were included in the allele model, a total 2256 T2DM cases and 2228 NDM controls were included in the other three genetic models (the additive; recessive and dominant models). In overall analysis, the IGF-1 rs35767 was shown to be significantly associated with increased T2DM risk for the allele model (T vs. C: OR = 1.251, 95% CI: 1.082–1.447, p = 0.002), additive model (homozygote comparisons: TT vs. CC: OR = 2.433, 95% CI: 1.095–5.405, p = 0.029; heterozygote comparisons: TC vs. CC: OR = 1.623, 95% CI: 1.055–2.495, p = 0.027) and dominant model (TT + CT vs. CC: OR = 1.934, 95% CI: 1.148–3.257, p = 0.013) with random effects model. After omitting Gouda’s study could reduce the heterogeneity, especially in the recessive model (TT vs. CC + CT: I2 = 38.7%, p = 0.163), the fixed effects model for recessive effect of the T allele (TT vs. CC + CT) produce results that were of borderline statistical significance (OR = 1.206, 95% CI: 1.004–1.448, p = 0.045). And increasing the risk of T2DM in Uyghur population of subgroup for the allele model.Conclusion: The initial analyses that included all studies showed statistically significant associations between the rs35767 SNP and type 2 diabetes, but after removing the Gouda et al. study produced results that were mostly not statistically significant. Therefore, there is not enough evidence from the results of the meta-analysis to indicate that the rs35767 SNP has a statistically significant association with type 2 diabetes.

The dopamine transporter (DAT) is encoded by the SLC6A3 gene and plays an important role in the regulation of the neurotransmitter dopamine. The SLC6A3 gene contains several repetition alleles (3–11 repeats) of a 40-base pair variable number of tandem repeats (VNTR) in the 3′-untranslated region (3′-UTR), which may affect DAT expression levels. The 10-repeat (10R) allele could play a protective role against PD. However, inconsistent findings have been reported.Methods: A comprehensive meta-analysis was performed to accurately estimate the association between the 10R allele of the 3′-UTR VNTR in SLC6A3 and PD among four different genetic models.Results: This meta-analysis included a total of 3,142 patients and 3,496 controls. We observed a significant difference between patients and controls for the allele model (10R vs. all others: OR = 0.860, 95% CI: 0.771–0.958, P = 0.006), pseudodominant model (10R/10R + 10R/9R vs. all others: OR = 0.781, 95% CI: 0.641–0.952, P = 0.014) and pseudorecessive model (10R/10R vs. all others: OR = 0.858, 95% CI: 0.760–0.969, P = 0.013) using a fixed effects model. No significant differences were observed under the pseudocodominant model (10R/9R vs. all others: OR = 1.079, 95% CI: 0.945–1.233, P = 0.262). By subgroup analysis, the 10R, 10R/10R and 10R/9R genotypes were found to be significantly different from PD in Asian populations.Conclusion: Our findings suggest that the SLC6A3 10R may be a protective factor in susceptibility to PD.

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This meta-analysis assessed the association between the 10R allele of the 3′-UTR VNTR in the SLC6A3 gene and PD, and it included a total of 18 published studies. In general, our findings suggested that the 10R alleles and 10R/10R and 10R/10R + 10R/9R genotypes of the VNTR

The post porcelain insulator is pulled by bus, which will produce stress in post porcelain insulator, and stress concentration is in the root of the umbrella. Therefore, there will be break accident if it is not installed properly. Firstly, the fracture theory of porcelain insulator is summarized from the characteristics of ceramic materials, including its way to fracture and the characteristic quantities emerged when fracturing. Then the brittle fracture theory of the maximum tensile stress theory of the porcelain insulator is summarized. The ANSYS based on finite element method is used for simulation analysis. The finite element model of different types of porcelain insulators is established, the stress distribution of the porcelain post insulator in different directions and of different sizes are calculated. The maximum stress value of the structure of the umbrella skirt is changed correspondingly by changing the direction and size of the force of the bus line. The relationship between stress and load force mainly presents a linear relation with load. According to the calculation of the stress distribution of the porcelain insulator using finite element method, the relationship curves of stress and load direction and magnitude are plotted, and the theoretical results are verified.