Objective To observe the role of the renin-angiotensin system in myocardial injury induced by experi-mental vascular dementia.Methods Eighteen adult male rats were categorized into a normal group,sham group,and modified 2-vessel occlusion group(model).To assess the myocardial injury caused by experimental vascular dementia,immunostaining was conducted to evaluate the interstitial collagen fraction and myocyte cross-sectional ar-ea.The concentrations of angiotensin Ⅱ(Ang Ⅱ)and angiotensin 1-7(Ang1-7)in the serum,as well as the ex-pression levels of angiotensin converting enzyme(ACE),angiotensin converting enzyme 2(ACE2),Ang Ⅱ,Ang1-7,angiotensin type 1(AT1)receptor,and Mas receptor in the myocardium,were assessed.Results Modified 2-vessel occlusion led to pronounced cognitive dysfunction(P＜0.01)and myocardial injury(P＜0.000 1)when compared to the sham and normal groups.Additionally,modified 2-vessel occlusion induced significant upregulation of the ACE/Ang Ⅱ/AT1 receptor axis(P＜0.01)and downregulation of the ACE2/Ang1-7/Mas axis(P＜0.05)of the renin-angiotensin system in the myocardium.Conclusion Myocardial injury in rats with experimental vascu-lar dementia may be related to dysregulation of the renin-angiotensin system.

Objective To observe the effects of water rehabilitation training on long voyage fatigue injury of submariners.Methods Totally 120 submariners from a submarine training base were selected in October 2021 as research subjects,including 60 submariners with low back fatigue injury and another 60 ones with shoulder neck fatigue injury,and the former was designated as experimental group(with water rehabilitation training)and the latter was assigned as control group(with routine rehabilitation training).The various evaluation indexes and the change rates were compared between the 2 groups.Results Of the submarines with shoulder and neck fatigue injury,the degrees of forward flexion activity,posterior extension activity,lateral bending activity and rotation activity in the experimental group were obviously superior to those of the control group,with statistical significance(P<0.01).Of the submarines with low back fatigue injury,the joint mobility of forward flexion,posterior extension and lateral flexion in the experimental group was better than that before training,and the mobility of the waist at various directions in the control group also imprved to a certain extent.The degrees of forward flexion activity and posterior extension activity were all significantly increased in the experimental group(P<0.05).Conclusion Water rehabilitation has both the advantages of hydrotherapy and water exercise,which could relax muscles,accelerate recovery of fatigue injury,and is beneficial to the prevention and rehabilitation of long voyage fatigue injury.Therefore,it is of ideal practical significance and practical value.