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Objective@#To detect the hemodynamic mechanism of the novel endovascular stent on complicated abdominal aortic aneurysms by Computational Fluid Dynamics(CFD) firstly, and then compare the effect of the novel endovascular stent and the streamliner multilayer flow modulator(SMFM) stent.@*Methods@#All medical images were obtained by computed tomography. A semiautomatic segmentation protocol within Mimics(v17.0; Materialise, Leuven, Belgium) was used to extract the threedimensional aortic aneurysms. The stents was generated numerically and fitted along the aortic aneurysms. The lumen volume represented the fluid domain that was discretised in smaller volumes, which defined a mesh within the ICEM software(Ansys ICEM CFD v15.0). Hemodynamic analysis was performed with software Fluent 16.0.@*Results@#Both kinds of stents can change the pattern of flow distribution. Compared with SMFM, the novel endovascular stent can significantly reduce the flow velocity in aneurysms, the shear force and the pressure on the aneurysms wall.What’s more, the flow velocity of the branch artery was accelerated by the novel endovascular stent.@*Conclusion@#The novel endovascular stent can significantly reduce the flow velocity in aneurysms, the shear force and the pressure on the aneurysms wall, and acceleratethe the flow velocity of the branch artery.
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Objective:To detect the hemodynamic mechanism of the novel endovascular stent on complicated abdominal aortic aneurysms by Computational Fluid Dynamics(CFD) firstly, and then compare the effect of the novel endovascular stent and the streamliner multilayer flow modulator(SMFM) stent.Methods:All medical images were obtained by computed tomography. A semiautomatic segmentation protocol within Mimics(v17.0; Materialise, Leuven, Belgium) was used to extract the threedimensional aortic aneurysms. The stents was generated numerically and fitted along the aortic aneurysms. The lumen volume represented the fluid domain that was discretised in smaller volumes, which defined a mesh within the ICEM software(Ansys ICEM CFD v15.0). Hemodynamic analysis was performed with software Fluent 16.0.Results:Both kinds of stents can change the pattern of flow distribution. Compared with SMFM, the novel endovascular stent can significantly reduce the flow velocity in aneurysms, the shear force and the pressure on the aneurysms wall.What’s more, the flow velocity of the branch artery was accelerated by the novel endovascular stent.Conclusion:The novel endovascular stent can significantly reduce the flow velocity in aneurysms, the shear force and the pressure on the aneurysms wall, and acceleratethe the flow velocity of the branch artery.
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Objective To investigate the expressions of GDNF and GFRα1 in childhood nephroblastoma, and therefore its clinical significance. Methods The expression levels of GDNF and GFRα1 were examined by immunohistochemistry of 30 parrafin samples from nephroblastoma section as well as 16 parrafin samples of peritumor renal tissue. Results The pos?itive expression rate of GDNF and GFRα1 in nephroblastoma were higher than those in normal renal tissue(66.7%vs 6.3%;63.3%vs 6.3%). GDNF and GFRα1 were strongly expressed in epithelium and embryo bud, but weakly expressed in lobus intermedius of nephroblastoma. There was no correlation between the expressions of GDNF and GFRα1 with histological types, clinical stage and metastasis of nephroblastoma of patients. Conclusion High expression of GDNF and GFRα1 in childhood nephroblastoma might indicate its role in tumor development.