This paper presents the results of an experimental research designed to investigate the combined effects of corrosion rate, concrete cover thickness, and stirrup spacing on the bond performance between reinforcement and concrete of reinforced concrete (RC) specimens. The RC specimens were immersed into sodium chloride solution to eliminate the passivation film on reinforcement. Then, an accelerated corrosion method was applied to corrode reinforcement embedded in concrete specimens. Pullout test was carried out to establish empirical formulas for ultimate slip and ultimate bond strength of RC specimens with three different corrosion rates, different concrete cover thicknesses, and different stirrup spacings. In addition, the bond-slip relation model was developed to predict and evaluate the bond performance of RC specimens. Finally, the ultrasonic technology was used to detect the damage of RC specimens, and the corresponding nonlinear coefficient β was proposed to characterize the damage degree of RC specimens. The susceptibility of β on the damage of specimens was compared with that of ultrasonic velocity, indicating β was more appropriate to evaluate the damage of RC specimens.

Effect of donepezil on the homocysteine (Hcy) level in serum of Alzheimer's disease (AD) patients and correlation between Hcy and dyssomnia was investigated. A retrospective analysis of 124 AD patients in Zhengzhou University People's Hospital between January 2015 and October 2017 was performed, including 64 cases in the observation group and 60 cases in the control group. The control group was treated with folic acid, vitamin B12 and memantine hydrochloride tablet, and the observation group combined with donepezil on this basis, and both groups were treated for 4 months. The Hcy level before and after treatment was detected in the groups using ELISA method, dyssomnia score of patients was performed before and after treatment in the observation group according to Pittsburgh Sleep Quality Index (PSQI), and correlation analysis between the Hcy level before and after treatment and dyssomnia was performed in AD patients in the study group using Pearson's correlation analysis. The differences were statistically significant in the Hcy level before and after treatment in both groups (P<0.001). The Hcy level after treatment in the observation group was significantly lower than that in the control group (P<0.001). The dyssomnia score before treatment was higher that after treatment in the observation group (P<0.001). There was a positive correlation between the Hcy level before treatment and dyssomnia score (r=0.658, P<0.001). There was also a positive correlation between the Hcy level after treatment and dyssomnia score (r=0.670, P<0.001). Donepezil can effectively improve the sleep function of patients and reduce the Hcy level in serum in the treatment of AD patients. The application of donepezil was of great significance in the clinical treatment of AD patients.

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This paper experimentally investigates the working behavior characteristics of an integral abutment curved box-girder (IACBG) bridge model based on the structural stressing state theory. First, the stressing state of the bridge model is represented by generalized strain energy density (GSED) values at each load Fj and characterized by the normalized GSED sum Ej,norm. Then, the Mann-Kendall (M-K) criterion is adopted to detect the stressing state mutations of the bridge model from Ej,norm-Fj curve in order to achieve the new definition of structural failure load. Correspondingly, the stressing state modes for the bridge model’s sections and internal forces are reached in order to investigate their variation characteristics and the coordinated working behavior around the updated failure load. The unseen knowledge is revealed by studying working behavior characteristics of the bridge model. Therefore, the analytical results could provide a new structural analysis method, which updates the definition of the existing structural failure load and provides a reference for future design of the bridges.