Objective To establish a mouse model of traumatic brain injury(TBI),to investigate the effects of visual cortex injury on neurobiology and cognitive function of the visual cortex.Methods Stereotaxic-guided graded cortical impacts(impact velocity was 1-4m/s)were administered to the primary visual cortex(V1)-associated skull surface in C57BL/6mice(8-week-old)with intact dura mater.Two weeks after the impact,the changes of neuronal numbers were analyzed by immunofluorescence staining and confocal mi-croscope imaging.Similar and 2-hour novel object recognition tests were used to evaluate the model visual function of mice.Open field tests and 24-hour novel object identification tests were used to assess the model non-visual abilities of mice,such as mobility,anxiety,and cognition.Results The number of superficial neurons in the mice's V1dropped by roughly 10％(P＜0.01)with an impact velocity of 4m/s,which was similar to what happens in individuals with mild brain injury.The recognition index(RI)of the TBI model mice was found to be significantly lower than that of the control group in the similar object recognition test(0.51±0.06 vs 0.58±0.05,P＜0.05).However,in the 2-hour novel object recognition test,no statistically significant difference in RI was detected between the TBI model mice and the control group(P＞0.05).Furthermore,the open field test indicated no significant disparities in locomotion speed or the time spent in the central area between the TBI model mice and the control group(P＞0.05).Similarly,the 24-hour novel object recognition test revealed no significant difference in RI between the TBI model mice and the control group(P＞0.05).Conclusion A mouse model simulating superficial injury to V1 was created through a controlled physical impact,characterized by a velocity of4m/s,a penetration depth of 0.5mm,and a dwell time of 0.5seconds.The visual capabilities of the model mice exhibited mild impairment,where-as their motor and cognitive functions remained intact.This model offers a novel research tool for exploring the mechanisms underlying the recovery of visual deficits following TBI.

Objective To establish a mouse model of traumatic brain injury(TBI),to investigate the effects of visual cortex injury on neurobiology and cognitive function of the visual cortex.Methods Stereotaxic-guided graded cortical impacts(impact velocity was 1-4m/s)were administered to the primary visual cortex(V1)-associated skull surface in C57BL/6mice(8-week-old)with intact dura mater.Two weeks after the impact,the changes of neuronal numbers were analyzed by immunofluorescence staining and confocal mi-croscope imaging.Similar and 2-hour novel object recognition tests were used to evaluate the model visual function of mice.Open field tests and 24-hour novel object identification tests were used to assess the model non-visual abilities of mice,such as mobility,anxiety,and cognition.Results The number of superficial neurons in the mice's V1dropped by roughly 10％(P＜0.01)with an impact velocity of 4m/s,which was similar to what happens in individuals with mild brain injury.The recognition index(RI)of the TBI model mice was found to be significantly lower than that of the control group in the similar object recognition test(0.51±0.06 vs 0.58±0.05,P＜0.05).However,in the 2-hour novel object recognition test,no statistically significant difference in RI was detected between the TBI model mice and the control group(P＞0.05).Furthermore,the open field test indicated no significant disparities in locomotion speed or the time spent in the central area between the TBI model mice and the control group(P＞0.05).Similarly,the 24-hour novel object recognition test revealed no significant difference in RI between the TBI model mice and the control group(P＞0.05).Conclusion A mouse model simulating superficial injury to V1 was created through a controlled physical impact,characterized by a velocity of4m/s,a penetration depth of 0.5mm,and a dwell time of 0.5seconds.The visual capabilities of the model mice exhibited mild impairment,where-as their motor and cognitive functions remained intact.This model offers a novel research tool for exploring the mechanisms underlying the recovery of visual deficits following TBI.

Objective:To compare the resting energy expenditure(REE)characteristics among young men with different body mass indexes(BMI).Methods:Thirty young men[average age was(26.93± 4.16)years]were enrolled in this study.They underwent resting metabolism tests in the Department of Sports Medicine of Peking University Third Hospital from December 2017 to June 2021.The resting meta-bolic rate(RMR)was measured by indirect calorimetry,the body composition was measured by bioresis-tance antibody component analyzer.The REE characteristics were analyzed,and 11 predictive equations were used to estimate RMR and compared with the measured value.The differences were analyzed by paired t-test and intra-class correlation coefficient(ICC).Results:The RMR of the overall 30 young men was(1 960.17±463.11)kcal/d(1 kcal=4.186 8 kJ).Including(1 744.33±249.62)kcal/d in those with normal BMI,which was significantly lower than that in those who were overweight or obese[(2 104.06±520.32)kcal/d,P＜0.01],but the weight-corrected RMR in those with normal BMI was significantly higher than that in those who were overweight or obese[(24.02±2.61)kcal/(kg·d)vs.(19.98±4.38)kcal/(kg·d),P＜0.01].The RMR was significantly and positively correlated with body weight,adiposity,lean body mass,body surface area,and extracellular fluid in the subjects with diffe-rent BMI(all P＜0.05).The predicted values of the 11 prediction equations were not in good agreement with the measured values(all ICC＜0.75),with relatively high agreement between the pre-dicted and measured values of the World Health Organization(WHO)equation in overweight obese young men(ICC=0.547,P＜0.01).Conclusion:There were significant differences in RMR among young men with different BMI,and the RMR after weight correction should be considered for those who were overweight or obese.The consistency between the predicted values of different prediction equations and the actual measured values of RMR was relatively poor,and it is recommended to accurately measure RMR by indirect calorimetry.For overweight or obese young men,the WHO prediction equation can be considered to calculate RMR,but it is necessary to establish an RMR prediction equation applicable to different BMI populations.

Objective:To explore the features the gait of elderly persons with type 2 diabetes and peri-pheral neuropathy.Methods:Twenty patients no less than 60 years old with type 2 diabetes and peripheral neuropathy (DPN) formed a DPN group, while 20 counterparts with type 2 diabetes but without peripheral neuropathy composed the DM group, and another 20 healthy counterparts served as a control group. The three groups were tested using the Swedish Qualisys motion capture system and their walking speed, step length, step width, stride frequency and stride length, bipedal foot support phase time, single foot support phase time, peak plantar pressure, and regional-holding time were collected and compared.Results:The average walking speed, stride length and stepping frequency of the DPN group were all significantly lower than the other 2 groups′ averages. Their bipedal support phase was significantly longer, but their single foot support phase time was significantly shorter. And in the DPN group the average first and second peak plantar pressures and the second peak pressure time were significantly greater than the other groups′ averages.Conclusions:Elderly patients with type 2 diabetes and peripheral neuropathy have significant gait abnormalities, decreased walking stability, as well as increased plantar pressure and plantar compression time.