Objective To construct a transparent and visualized bionic model of human utricle and explore the biomechanical response of the utricle to linear acceleration.Methods Using three-dimensioanl(3D)printing technology and PVA-gelatin composite hydrogel fabrication method,a visual physical model of the utricle with a ratio of 10∶1 to the human body was successfully prepared.The biomechanical response of the utricle macula was investigated by varying acceleration and direction stimulation experiments.Results Under 1-5 Hz sinusoidal reciprocating linear excitation,the response amplitude of the bionic macula increased from 4.11 μm to 48.82 μm.The response amplitude of the bionic macula increased linearly with the acceleration.In addition,the macula showed deformation differences in response to acceleration in a specific direction.Conclusions The bionic utricle model prepared in this study can accurately simulate the working mechanism of human utricle,which is expected to provide a new way for the pathological study of vestibular dysfunction and expand a new direction for the application of bionic technology in the field of biomedical engineering.

Objective To construct a transparent and visualized bionic model of human utricle and explore the biomechanical response of the utricle to linear acceleration.Methods Using three-dimensioanl(3D)printing technology and PVA-gelatin composite hydrogel fabrication method,a visual physical model of the utricle with a ratio of 10∶1 to the human body was successfully prepared.The biomechanical response of the utricle macula was investigated by varying acceleration and direction stimulation experiments.Results Under 1-5 Hz sinusoidal reciprocating linear excitation,the response amplitude of the bionic macula increased from 4.11 μm to 48.82 μm.The response amplitude of the bionic macula increased linearly with the acceleration.In addition,the macula showed deformation differences in response to acceleration in a specific direction.Conclusions The bionic utricle model prepared in this study can accurately simulate the working mechanism of human utricle,which is expected to provide a new way for the pathological study of vestibular dysfunction and expand a new direction for the application of bionic technology in the field of biomedical engineering.

Objective To explore the biomechanical responses of the cupula of the human semicircular canal to three basic rotational perception processes.Methods A one-dimensional visual semicircular canal model was successfully fabricated using three-dimensional printing and hydrogel physical cross-linking technologies,and the response deformation of the cupula was explored by applying constant angular velocity,constant angular acceleration,and sinusoidal oscillation stimulations.Results The time constant of the biomimetic semicircular canal model was stable at approximately 3 s and close to the human time constant.The displacement deformation of the ampullary cupula was proportional to the angular acceleration applied.Under sinusoidal oscillation stimulation of 0.07-5.00 Hz,the gain of the semicircular canal increased from 1.54 um/° rises to 42.34 μm/°,but the phase difference decreased from 109.72° to 11.27°.Conclusions The biomimetic semicircular canal model prepared in this study can accurately simulate the working mechanism of the human semicircular canal and is expected to play a role in mechanism research and disease diagnosis of the human vestibular semicircular canal.

Objective:To compare the sedative and anti-anxiety effects of levo-tetrahydropalmatine (L-THP) and diazepam on conditioned fear model rats.Methods:According to the random number table method, 32 adult male rats were divided into blank group, model group, diazepam group and L-THP group(with 8 rats in each group). The conditioned fear model was reproduced by the plantar electric shock method. Four days after the modeling, the rats in diazepam group and L-THP group were given diazepam (3.6 mg/kg) and L-THP (25 mg/kg) were respectively gavaged once a day for 10 days, the rats in blank group and model group were given the same volume of saline. After the administration, the elevated plus maze test and the open field test were used to measure the anxiety behavior of the rats, and the sleep energy monitoring system was used to detect changes in sleep and energy-related indicators. SPSS 23.0 and Graphpad Prism 7.0 softwares were used for data analysis, multiple samples between groups were compared by one-way ANOVA, and LSD test was used for pairwise comparison.Results:The results of the elevated plus maze experiment showed that compared with the model group, the percentage of open-arm entry times ((11.27±8.78)%, (30.11±14.59)%, P<0.05) and the percentage of open-arm residence time ((1.94±1.48)%, (17.53±8.21)%, P<0.05) in diazepam group were all significantly increased. Compared with the model group, the open arm residence time, the percentage of open arm residence time and the percentage of open arm entry times in L-THP group showed an upward trend, but there was no statistical significance (all P>0.05). The results of the open field experiment showed that compared with the model group, the time of entering the central grid ((2.99±1.83) s, (6.94±3.52) s, P<0.05) and the time of entering the peripheral field ((297.01±1.83) s, (293.30±3.52) s, P<0.05) in diazepam group both increased. Compared with the model group, there was no significant difference in the changes of various indexes in L-THP group (all P>0.05). The results of locomotor activities showed that the autonomic activity times of model group in nighttime was significantly lower than that of blank group((758.79±375.37)times/h, (1 101.93±525.96)times/h, P<0.05). Compared with the model group, the number of autonomous activities of rats in L-THP group in daytime ((820.57±364.60) times/min, (502.40±228.54)times/min, P<0.05) decreased, and the number of autonomous activities in the nighttime ((758.79±375.37) times/min, (1 146.85±309.69)times/min, P<0.05) increased, but there was no significant change in the number of autonomous activities in the whole day. Correlation analysis of energy metabolism related indexes and sleep time of rats in each group were analyzed. The experimental results showed that the daytime sleep time were negatively correlated with heat value ( r=-0.335, P<0.05), and the night sleep time was positively correlated with daytime heat value ( r=0.352, P<0.05). Conclusion:L-tetrahydropalmatine has no significant anti-anxiety effect in the concentration range used in this study, but its sedative and improving sleep activity rhythm are better than diazepam.