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Objective To study the effect of age-related white matter changes (ARWMC) on first symptomatic ischemic stroke events in the oldsters. Methods For the prospective study, a total of 368 eligible oldsters were enrolled in the study from January 2010 to August 2012. The degrees of ARWMC were assessed by ARWMC scale;according to the scores, they were divided into non ARWMC group, mild-moderate ARWMC group and severe ARWMC group. The patients were followed up once every 3 months. The clinical endpoint events and time (first symptomatic ischemic stroke, myocardial infarction and all-cause death) were recorded. Analyses of variance and Chi-square test were used to compare the differences of clinical data among the 3 groups. COX regression was used to assess the risk differences of first symptomatic ischemic stroke in the oldsters of three groups. Results After an average of follow-up for 48.7 months, 50 participants (13.6％) had first symptomatic ischemic stroke;25 (25.8％) were categorized as the severe ARWMC group, 22 (10.9％) were as the mild-medium group, and 3 (4.4％) were as the non ARWMC group. Among the three groups, the differences in age, history of hypertension, systolic blood pressure, incidence of clinical endpoint events and first symptomatic ischemic stroke, and follow-up time of endpoint events were statistically significant (P<0.05); patients from the severe ARWMC group were the oldest, and had the longest history of hypertension, the highest systolic blood pressure, the highest incidence of clinical end events and first symptomatic ischemic stroke, and the shortest follow-up period for clinical end events. COX regression analysis showed that the risk of first symptomatic ischemic stroke in the severe ARWMC group was about 8 times higher than that in the non ARWMC group (hazard ratio=9.012, 95％CI: 2.310-35.154, P=0.002). Conclusion In oldsters, severe ARWMC often accompany hypertension history and poor blood pressure controll, and it is an independent and serious risk factor for long-term first symptomatic ischemic stroke.
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Objective To seek a useful index for assessing the change of human gait function based on the application of wavelet entropy in the gait data analysis.Methods The ground reaction force(GRF)gait data of 2 groups(10 young and 10 elderly subjects)were acquired with Bertec 3 dimensional force measured system(a strain gauge force platform)during normal walking.The orthogonal discrete wavelet transform was used for decomposing the collected gait data.The relative wavelet energy and wavelet entropy were defined and calculated respectively.They were statistically analyzed with t-test technique respectively to evaluate the change of human gait function.Results There was significant difference between the relative wavelet energy from GRF gait data of the two subject groups.The average values of wavelet entropy from the GRF gait data of elderly subject group were obviously less than those from the GRF gait data of young subject group.With the value of significance level of t-test P