OBJECTIVE Exploring the specific changes in brain signal variability during healthy aging using functional near-infrared spectroscopy technology.METHODS Twenty-eight young adults and 30 elderly adults were included,and functional near-infrared spectroscopy was used to record the changes in brain blood oxygen and calculate the brain signal variability during the execution of visual-audio dual tasks.RESULTS The brain signal variability of the elderly group was significantly reduced when performing visual-audio dual tasks,especially in the bilateral dorsolateral prefrontal cortex,right Broca,bilateral primary somatosensory cortex,bilateral Wernicke area,bilateral frontopolar area,bilateral primary motor cortex,bilateral somatosensory association cortex,bilateral orbitofrontal area,bilateral pre-motor and supplementary motor cortex.The brain signal variability in the left primary somatosensory cortex(r=-0.385,P=0.043)and right primary somatosensory cortex(r=-0.386,P=0.042)of young adults was negatively correlated with visual reaction time;The brain signal variability in the right somatosensory association cortex(r=-0.371,P=0.044),left pre-motor and supplementary motor cortex(r=-0.393,P=0.032)of elderly adults was negatively correlated with visual reaction time.CONCLUSION Elderly individuals exhibit a significant reduction in neural signal variability within the prefrontal cortex and sensory related cortex,resulting in diminished neural dynamic adaptability that compromises behavioral performance during visual-audio dual tasks.

Humans ; Olfaction Disorders/etiology* ; Smell

Objective: To investigate the association between body mass index ( BMI ) and mortality risk among older Chinese based on the China Health and Retirement Longitudinal Study ( CHARLS ). Methods: The demographic features, BMI, prevalence of chronic diseases and mortality among the elderly at ages of 60 years and greater were captured from the CHARLS database from 2011 to 2018. A multivariable Cox proportional hazards regression model was used to examine the association between BMI and the risk of death. Results: Totally 6 023 subjects were enrolled, including 3 006 men ( 50.09% ) and 3 017 women ( 49.91% ), and 68.69% of the participants ( 4 137 subjects ) were at ages of 60 to 69 years. There were 637 subjects ( 10.58% ) with underweight, 1 544 ( 25.63% ) with overweight, and 557 ( 9.25% ) with obesity. During the follow-up period ( 35 091 person-years ), 1 035 subjects died. Multivariable Cox proportional hazards regression analysis revealed an increased risk of mortality among the underweight elderly ( HR=1.496, 95%CI: 1.261-1.775 ) and a reduced risk of mortality among the obese elderly ( HR=0.671, 95%CI: 0.511-0.881 ) relative to the elderly with normal weight, after adjustment for age, gender, smoking, household registration, administration of anti-diabetic drugs, administration of anti-dyslipidemia drugs, and administration of anti-hypertensive drugs. Conclusion It is found that the risk of mortality among the Chinese elderly correlatives with BMI through the analysis of CHARLS data.

Objective To determine the feasibility of neck vessel wall imaging technology with three?dimensional variable?flip?angle turbo spin?echo (3D T1w?SPACE) for the detection of carotid atherosclerotic disease before revascularization. Methods Thirty?one patients who underwent carotid endarterectomy (CEA) and fifty?three patients who underwent carotid stenting (CAS) were enrolled prospectively. Neck vessel wall imaging examination were performed in all patients whilecarotid artery DSA were performed in all CAS patients. Quantitative measurements including stenosis, lesion length, and the presence or absence of plaque ulceration obtained with 3D T1w?SPACE and DSA were independently determined. And images of the 3D T1w?SPACE were compared with corresponding histology to identify major plaque components including intraplaque hemorrhage (IPH), lipid rich necrotic core (LRNC), and calcification (CA). The consistency rate, sensitivity, specificity, positive predictive value and negative predictive value were used to assess diagnostic value. Bland?Altman plots, intraclass correlation coefficient (ICC), and Cohen Kappa were determined. Results DSA was served as the reference standard. There was an excellent correlation between 3D T1w?SPACE and DSA images in measuring stenosis (r=0.984, P<0.01) and luminal stenosis [ICC=0.98 (95% confidence interval: 0.96-0.99)]. Bland?Altman plots showed that the two examinations were in good consistency in evaluating the extent of stenosis. Sensitivity (89.5%) and specificity (95.1%) was high in 3D T1w?SPACE images compared to DSA for the detection of ulcers. The consistency rate between 3D T1w?SPACE images and histological results for IPH, LRNC and CA detection were 85.7%, 82.1% and 92.9%, respectively. Sensitivity and specificity were 90.0% and 75.0% for IPH;83.3% and 80.0% for LRNC; 91.3% and 100.0% for CA respectively. However, lesion length measurements by using 3D T1w?SPACE were longer than those measured by using DSA (P<0.01).Conclusion Neck vessel wall imaging technology with 3D T1w?SPACE is a noninvasive and accurate technique for the diagnosis of carotid artery atherosclerotic disease before revascularization.