ABSTRACT
Objective To analyze factors that affect axial mechanical performance of the posterior pedicle fixation system. Methods The mechanical model for axial mechanical properties of the posterior pedicle fixation system was established to perform mechanical analysis. By referring to the Standard YY/T 0961-2014, tests on axial ejection force and axial clamping torque of JHL-I multi-axis components, JHL-I single-axis components, JHL-V multi-axis components and JHL-V single-axis components were performed by using Instron E3000 and Instron E10000 mechanical testing machines. Results The ejection rigidity of the single-axis component of vertebral nail system was significantly higher than that of the multi-axis component of vertebral nail system; the torsion rigidity of JHL-V was higher than that of JHL-I. The type and size of the locking bolt as well as its locking torque were the main factors affecting axial ejection force of the posterior spinal pedicle fixation system; the size of the locking bolt and the diameter of the connection rod were the main factors affecting axial clamping torque of the system; axial mechanical properties of the system could be improved by increasing the diameter of the connecting rod, the coefficient of friction between each connecting element, and the pitch diameter of the locking bolt. Conclusions The research findings provide references for optimizing and improving axial mechanical properties of the posterior pedicle fixation system.
ABSTRACT
Objective To analyse change of neuroendocrine hormone and cardiac ultra ejection force in patients with heart failure before and after treatment with Huangqi Decoction.Methods 100 patients diagnosed with chronic heart failure were collected.According to the different treatment regimens divided into two groups ( control group: conventional western medicine; traditional Chinese medicine group: conventional western medicine treatment +Astragalus Decoction orally for 2 weeks) , before and after treatment,nerve endocrine hormone using echocardiography evaluation index and ejection force were detected in two groups, and compare the results of data.Results Compared with control group, Chinese medicine group with better anti heart failure treatment, performance: the plasma calcitonin gene related peptide (CGRP), atrial natriuretic peptide (ANP), C type natriuretic peptide ( CNP ) , neuropeptide Y ( NPY ) levels were significantly lower ( P<0.05 ) . Capacity index significantly improved cardiac function (P<0.05).Left atrial diameter, left atrial maximum, minimum volume decreased significantly (P<0.05).Ejection force of left atrium and left ventricular increased significantly ( P<0.05 ) .The results were statistically significant.Conclusion Huangqi decoction can inhibit the secretion of CGRP, ANP, CNP,NPY and other neuroendocrine hormones in patients with heart failure, reduce cardiac load, increase cardiac ejection force.