Influence of electroacupuncture with acupoints selected along meridians on gene expression of angiotensinogen of myocardial ischemia rats

Objective:To observe the effects of electroacupuncture along meridians on the expression of angiotensinogen(AGT)mRNA in myocardial tissue of myocardial ischemia(MI)rats.Methods:SD rats were randomly divided into four groups:control group,MI model group,Neiguan(PC6)point group(EA group)and non-acupoint(the lateral-superior side of the hip)group.Myocardial infarction was produced in rats with 85 mg/kg of isoproterenol administered subcutaneously twice at an interval of 24 h.Rats of EA group and non-acupoint group were treated with electroacupuncture,once daily for five consecutive days.Gene chip was used to detect RAS-related genes of myocardial tissue from the model group and the EA group.Cardiac index and pathological staining were observed of four groups.Real-time quantitative fluorescent PCR was used to detect the expression of AGT mRNA in cardiac tissue.Results:The expression of RAS-related genes were different between the model group and the EA group.The difference of AGT mRNA was the most significant.The cardiac index and AGT mRNA expression in the model group were significantly higher than those in the control group(P<0.01).While those in the EA group were significantly lower than model group(P<0.05).The cardiac index and the expressions of AGT mRNA in the nonacupoint group were significantly higher than those in the EA group(P<0.01),and there was no difference with the model group.Conclusion:Electroacupuncture along meridians can improve myocardial ischemia in rats,and its mechanism may be related to the down-regulation of AGT mRNA expression in myocardial tissue.

Effects of electroacupuncture on rats with cognitive impairment:An iTRAQ-based proteomics analysis

Objective The study explores the effects of electroacupuncture(EA)at the governing vessel(GV)on proteomic changes in the hippocampus of rats with cognitive impairment.Methods Healthy male rats were randomly divided into 3 groups:sham,model and EA.Cognitive impairment was induced by left middle cerebral artery occlusion in the model and EA groups.Rats in the EA group were treated with EA at Shenting(GV24)and Baihui(GV20)for 7 d.Neurological deficit was scored using the Longa scale,the learning and memory ability was detected using the Morris water maze(MWM)test,and the proteomic profiling in the hippocampus was analyzed using protein-labeling technology based on the isobaric tag for relative and absolute quantitation(iTRAQ).The Western blot(WB)analysis was used to detect the proteins and validate the results of iTRAQ.Results Compared with the model group,the neurological deficit score was significantly reduced,and the escape latency in the MWM test was significantly shortened,while the number of platform crossings increased in the EA group.A total of 2872 proteins were identified by iTRAQ.Differentially expressed proteins(DEPs)were identified between different groups:92 proteins were upregulated and 103 were downregulated in the model group compared with the sham group,while 142 proteins were upregulated and 126 were downregulated in the EA group compared with the model group.Most of the DEPs were involved in oxidative phosphorylation,glycolipid metabolism and synaptic transmission.Furthermore,we also verified 4 DEPs using WB technology.Although the WB results were not exactly the same as the iTRAQ results,the expression trends of the DEPs were consistent.The upregulation of heat-shock proteinβ1(Hspb1)was the highest in the EA group compared to the model group.Conclusion EA can effect proteomic changes in the hippocampus of rats with cognitive impairment.Hspb1 may be involved in the molecular mechanism by which acupuncture improves cognitive impairment.

Research on ultrasonic-assisted drilling in micro-hole machining of the DD6 superalloy

The DD6 nickel-based superalloy exhibits remarkably high temperature properties;therefore,it is employed as a crucial structural material in the aviation industry.Nevertheless,this material is difficult to process.Ultrasonic-assisted drilling(UAD)combines the characteristics of vibration processing technology and conventional drilling technology,significantly improving the machinability of difficult-to-machine materials.Thus,UAD experiments were performed on micro-hole machining of DD6 superalloy in this study.The effects of amplitude,frequency,spindle speed,and feed rate on thrust force,machining quality,and drill bit wear were studied;thereafter,a comparison was drawn between these effects and those of conventional drilling(CD).The experimental results reveal that the thrust force decreases with an increase in spindle speed or a decrease in feed rate for both UAD and CD.UAD can significantly reduce the thrust force.With the same processing parameters,the greater the amplitude,the greater the reduction of the thrust force.The surface roughness of the hole wall produced by UAD is lower than that of CD.Compared with CD,UAD reduces the burr height,improves machining accuracy,and reduces drill bit wear.

Thrust force model for ultrasonic-assisted micro drilling of DD6 superalloy

As a typical refractory material,the DD6 nickelbased single-crystal superalloy has important applications in the aviation industry.Ultrasonic-assisted drilling is an advanced machining method that significantly improves machining of refractory materials.The drilling thrust force influences the hole surface quality,burr height,and bit wear.Therefore,it is necessary to predict the thrust force during ultrasonic-assisted drilling.However,there are few reports on the modeling of the thrust force in the ultrasonicassisted drilling of micro-holes.A thrust force prediction model for ultrasonic-assisted micro-drilling is proposed in this study.Based on the basic cutting principle,the dynamic cutting speed,dynamic cutting thickness,and acoustic softening effect caused by ultrasonic vibrations are factored into this model.Through model calibration,the specific friction force and specific normal force coefficients were determined.The model was verified through ultrasonic-assisted drilling experiments conducted at different feed rates,spindle speeds,frequencies,and amplitudes.The maximum and minimum errors of the average thrust force were 10.5%and 2.3%,respectively.This model accurately predicts the thrust force based on the parameters used for ultrasonic-assisted micro-hole drilling and can assist in the analysis and modeling of DD6 superalloy processing.