Objective: To develop a polyvinylidene fluoride (PVDF)-based instrument which may be used to measure bite force in natural teeth as well as in denture. Methods: The PVDF film was used as transducer. Electricity amplifier, lowpass filter, secondary magnifier in metrical circuit, and collection with disposal system were employed to produce the instrument for bite force measurement. The demarcating system was MTS-858. The instrument was used to measure the dynamic force in laterotrusion in 9 volunteers with Angle I occlusion. Results: The instrument was produced.By the used of the instrument the peak value of bite force (N) in the 9 subjects was 277.3?78.4 on the main functional side (MFS) and 258.7?83.3 on the subfunctional side (SFS).The time(ms) needed in the four phases on MFS was 65.6?7.3,354.4?66.1,116.3?25.0 and 226.9?35.8;that on SFS 67.5?6.6,394.4?65.3,141.9?25.6 and 167.5?41.9,respectively.Conclusion: The new system is steady and sensitive for bite force measurement.

Objective To evaluate left ventricular(LV)myocardial contraction patterns and function when pacing in different right ventricular(RV)sites and discuss echocardiogarphic method to evaluate physiologcal pacing mode.Methods This study included 26 patients with paroxysmal supraventricular tachycardia without organic heart disease.Four pacing modes including right atrium pacing(AAI),RV apex pacing(VVI-RVA),RV septal pacing(VVI-IVS)and RV outflow tract pacing(VVI-RVOT)were performed on the patients in a random order after succussful radiofrequency ablation.The parameters measured in each pacing mode included(1)LV systolic function parameters:LV twist angle(Twist),aortic systolic velocity-time integral(VTIAo)and LV global strain(Gε)；(2)LV contracting pattern:segmental peak systolic strain(Sε),the time to peak value(TPε),and the distribution of segmental Sε,TPε in each layer or wall.The relationship between Sε,TPε of each wall was analyzed.[Results]Pacing from RV sites showed lower Twist,VTIAO and Gε than AAI mode.Gε demonstrated significant difference in three RV sites pacing mode(VVI-RVOT＞VVI-IVS＞VVI-RVA,P＜0.05).Compared with the AAI mode,the distribution of segmental Sε,TPε in the each layer or wall alerted significantly in three RV sites pacing mode,especially in VV1-RVA.The distribution pattern was similar in VVI-RVOT and VVI-IVS.Furthermore,the wall Sε collated negtively with wall TPε(r =-0.51,P＜0.001).[Conclusions]Compared with AAI mode,RV pacing,especially the VVI-RVA induced the alternation of LV contraction patterns and reduction of systolic function.Longitudinal strain parameters can be used to assess the myocardial contraction patterns and function in different pacing mode.

Objective To investigate influence of different doses of dexmedetomidine on hemodynamics of pregnancy-induced hypertension syndrome (PIH) patients with cesarean section.Methods A total of 325 PIH cases in our hospital were divided into control group and A,B,C,D groups,with 65 cases in each group.The control group received only basic anesthesia,A,B,C,D groups were given dexmedetomidine intravenous infusion of 0.1,0.2,0.3,0.4 μg/(kg · h),respectively.Systolic blood pressure (SBP),diastolic blood pressure (DBP),heart rate (HR) and other indicators before epidural administration (T0),skin incision (T1),fetal delivery (T2),at the end of surgery (T3) were recorded.Results SBP,DBP,HR of 4 time points in 5 groups had a significant difference (P ＜ 0.05).At T0,SBP,DBP and HR of 5 groups were significantly higher than that of T1,T2,T3 (P ＜ 0.05).At T1,SBP,DBP,HR were significantly higher than that of T2 and T3 (P ＜ 0.05),At T2,SBP,DBP,HR of 5 groups were significantly higher than T3 (P ＜ 0.05).At T0,SBP,DBP,HR among 5 groups showed no significant difference (P ＞ 0.05).At T1 ～ T3,DBP,HR SBP of the 5 groups had a significant difference (P ＜ 0.05),SBP DBP and HR in D group were significantly lower than that of A,B,C groups,and control group (P ＜ 0.05).SBP,DBP,HR in C group were significantly lower than B group,and the control group (P ＜ 0.05).SBP,DBP,HR in B group were significantly lower than A group and the control group (P ＜ 0.0 5);SBP,DBP,HR between A group and control group showed no significant difference (P ＞ 0.05).Conclusion The dose of 0.4 μg/(kg · h) for PIH patients with cesarean section has stable hemodynamics.With the increase of dexmedetomidine dose,the effect is more obvious.

Objective To investigate influence of different doses of dexmedetomidine on hemodynamics of pregnancy-induced hypertension syndrome (PIH) patients with cesarean section.Methods A total of 325 PIH cases in our hospital were divided into control group and A,B,C,D groups,with 65 cases in each group.The control group received only basic anesthesia,A,B,C,D groups were given dexmedetomidine intravenous infusion of 0.1,0.2,0.3,0.4 μg/(kg · h),respectively.Systolic blood pressure (SBP),diastolic blood pressure (DBP),heart rate (HR) and other indicators before epidural administration (T0),skin incision (T1),fetal delivery (T2),at the end of surgery (T3) were recorded.Results SBP,DBP,HR of 4 time points in 5 groups had a significant difference (P ＜ 0.05).At T0,SBP,DBP and HR of 5 groups were significantly higher than that of T1,T2,T3 (P ＜ 0.05).At T1,SBP,DBP,HR were significantly higher than that of T2 and T3 (P ＜ 0.05),At T2,SBP,DBP,HR of 5 groups were significantly higher than T3 (P ＜ 0.05).At T0,SBP,DBP,HR among 5 groups showed no significant difference (P ＞ 0.05).At T1 ～ T3,DBP,HR SBP of the 5 groups had a significant difference (P ＜ 0.05),SBP DBP and HR in D group were significantly lower than that of A,B,C groups,and control group (P ＜ 0.05).SBP,DBP,HR in C group were significantly lower than B group,and the control group (P ＜ 0.05).SBP,DBP,HR in B group were significantly lower than A group and the control group (P ＜ 0.0 5);SBP,DBP,HR between A group and control group showed no significant difference (P ＞ 0.05).Conclusion The dose of 0.4 μg/(kg · h) for PIH patients with cesarean section has stable hemodynamics.With the increase of dexmedetomidine dose,the effect is more obvious.

Objective To investigate the effect and mechanism of Tiaobu Xinshen Prescription(Codonopsis Radix,Polygoni Multiflori Radix Praeparata,Lycii Fructus,Astragali Radix,etc.)on synaptic plasticity in 5xFAD transgenic mice with Alzheimer's disease(AD).Methods Eighteen 5-month-old male wild-type(WT)mice and 18 5xFAD transgenic mice were randomly divided into control group(0.9％NaCl),Tiaobu Xinshen Prescription group(granules,4.18 g·kg-1)and Aricept group(Donepezil Hydrochloride,0.625 mg·kg-1),with six mice in each group.According to the above groups,the rats were given intragastric administration once a day for 60 days.The ultrastructure of hippocampus in mice was observed by transmission electron microscopy.Western Blot was used to detect the protein expression levels of Synaptophsin,PSD-95,p-NMDAR1,NMDAR1,p-CaMKⅡa,CaMKⅡa,PI3K,p-Akt,Akt,p-mTOR and mTOR in mouse cortical tissue.Results Compared with the WT mice control group,the ultrastructure of synapses in the hippocampal CA1 region of the 5xFAD control group was irregular,the mitochondria was atrophied and reduced,the mitochondrial cristae was broken and disappeared,the synaptic membrane was irregularly and curved,the synaptic vesicles were reduced,and the postsynaptic density(PDS)was thinned or even broken.The protein expressions of Synaptophsin,PSD-95,p-NMDAR1/NMDAR1,p-CaMKⅡa/CaMKⅡa,PI3K,p-Akt/Akt and p-mTOR/mTOR in the cortex were significantly down-regulated(P<0.05).Compared with the mice in the 5xFAD control group,the ultrastructure of synapses in the hippocampal CA1 region of the mice in the Tiaobu Xinshen Prescription 5xFAD group was significantly changed,the number of mitochondria was increased,the number of synaptic vesicles was increased,the synaptic membrane was intact,and the postsynaptic density was thickened.The protein expressions of Synaptophsin,PSD-95,p-NMDAR1/NMDAR1,p-CaMKⅡa/CaMKⅡa,PI3K,p-Akt/Akt and p-mTOR/mTOR in the cortex were significantly up-regulated(P<0.05).Conclusion Tiaobu Xinshen Prescription may promote the synthesis of synaptic plasticity-related proteins by activating the PI3K/Akt/mTOR pathway,thereby improving the cognitive dysfunction of AD.

Objective:To investigate the alteration of right ventricular function after catheter ablation in patients with persistent atrial fibrillation(PAF) and concomitant heart failure with preserved ejection fraction (HFpEF).Methods:The prospective observational study was performed in patients with HFpEF-PAF and undergoing first-time radiofrequency ablation procedures in the First Affiliated Hospital of Nanjing University between May to December 2019. Right ventricular functional parameters were measured before and 5 days, 1, 3, 6 and 12 months after the ablation by transthoracic echocardiography, respectively, including the right ventricular fractional area change (RVFAC), tricuspid annular plane systolic excursion(TAPSE), tricuspid annular diameter (TVAD), tricuspid annular peak systolic speed(TDI-S′) and longitudinal strain of right ventricular free wall (RVFLS). Meanwhile, routine ECG and Holter recordings were performed at each follow-up time point.Results:In this study, atrial fibrillation (AF) recurrence occurred in 4 patients at the 3rd month after ablation, and 7 patients failed to follow up due to the Covid-19. Finally, 19 patients were followed up for the evaluation of cardiac function after catheter ablation. Compared with pre-ablation, right ventricular structural and functional paramters(RVFAC, TAPSE, TVAD, TDI-S′, RVFLS) improved significantly at all stages of follow-up( all P<0.05). Patients with atrial fibrillation recurrence had lower RVFLS and TDI-S′ at the baseline( P=0.039, P=0.019). Conclusions:Right ventricular function could improve in HFpEF-PAF patients who maintain sinus rhythm after radiofrequency ablation.