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Objective:To evaluate the effect of transcutaneous electrical acupoint stimulation (TEAS) at Neiguan on dexmedetomidine-induced bradycardia in patients.Methods:Sixty American Society of Anesthesiologists physical status Ⅰ or Ⅱ patients, aged 20-50 yr, weighing 48-60 kg, scheduled for elective gynecological surgery under general anesthesia, were divided into 2 groups ( n=30 each) using a random number table method: control group (group C) and TEAS group (group T). Dexmedetomidine 1 μg/kg was infused intravenously over 10 min followed by intravenous infusion 0.5 μg·kg -1·min -1 in two groups, and the patients in group T simultaneously received TEAS (frequency 2/100 Hz, disperse-dense wave, intensity 5-10 mA according to the current that could be tolerated) at bilateral Neiguan acupoints.The stimulator was only connected, and no current was given in group C. Before the infusion of dexmedetomidine (T 0) and at 10 min of dexmedetomidine infusion (T 1), mean arterial pressure (MAP) and heart rate (HR) was recorded, and electrocardiogram (ECG) was collected to calculate the PR interval, QT interval, QT interval, Tp-e interval and index of cardiac electrophysiological balance (iCEB). The development of arrhythmia was recorded. Results:Compared with the baseline value at T 0, HR was significantly decreased, and QT interval and PR interval were prolonged at T 1 in two groups, and iCEB was increased, and Tp-e interval was prolonged at T 1 in group C ( P<0.05). Compared with group C, HR was significantly increased, PR interval and Tp-e interval were shortened at T 1, and the incidence of bradycardia and atrioventricular block was increased in group T ( P<0.05). Conclusion:TEAS at Neiguan can decrease the risk of bradycardia induced by dexmedetomidine, and the mechanism may be related to shortening atrioventricular conduction time and reducing heterogeneity of ventricular repolarization in patients.
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Objective To evaluate the value of IVIM-DWI and DTI parameters in quantitative analysis and differential diagnosis of invasive breast carcinoma of no special type(NST).Methods We retrospectively analyzed 60 patients (63 lesions)who underwent MR examination in our hospital and all lesions were verified by pathologic results.MR protocol included DCE-MRI,IVIM-DWI using 14b values and DTI.The ADC,ADCslow,ADCfast,f,λ1of lesions were measured and compared by two independent samples t test between the benign lesions and NST.Logistic regression analysis was made using ADC,ADCslow,f,λ1as predictors in detecting and differentiating the NST,ROC analysis was performed to compare diagnostic performance based on the area under the curve(AUC).Results The ADC,ADCslow,ADCfast,f andλ1of NST were (1.49±0.63)×10-3mm2/s,(1.32±0.49)×10-3mm2/s,(25.98±21.84)×10-3mm2/s,0.20±0.13 and (4.98±0.47)×10-3mm2/s,these values of benign lesions were (2.31±0.66)×10-3mm2/s,(2.24±0.65)×10-3mm2/s,(18.71± 12.26)×10-3mm2/s,0.33±0.15 and(5.59±0.59)×10-3mm2/s.All parameters except ADCfast(P=0.271)had significantly statistical differences (P<0.000 1)between NST and benign lesions.The regression model showed that ADCslowwas an independent predictor in NST’s detection.Conclusion The ADC,ADCslow,f andλ1is helpful for differentiation between NST and benign lesions.The regression model is most valuable in NST detection and ADCslowis the preferred index.
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The proper orthogonai decomposition (POD) method for the instatiouary Navier-Stokes equations is considered. Several numerical approaches to evaluating the POD eigenfunctions are presented. The POD eigenfunctions are applied as a basis for a Galerkin projection of the instationary Navier-Stokes equations. And a low-dimensional ordinary differential models for fluid flows governed by the instationary Navier-Stokes equations are constructed. The numerical examples show that the method is feasible and efficient for optimal control of fluids.
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Two inequalities in the book Navier-Stokes Equations Theory and Numerical Analysis written by Roger Temam are improved via Schwarz's inequality and Young's inequality, and the coefficients of them are simplified from 21/4·31/2 and 21/2·33/4 to 21/4 and 23/4, respectively. Therefore, to some extent the approximating error can be reduced and the accuracy of approximation can be improved.
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We present an algorithm for numerical solution of transport equation in diffusive regimes, in which the transport equation is nearly singular and its solution becomes a solution of a diffusion equation. This algorithm, which is based on the Least-squares FEM in combination with a scaling transformation, presents a good approximation of a diffusion operator in diffusive regimes and guarantees an accurate discrete solution. The numerical experiments in 2D and 3D case are given, and the numerical results show that this algorithm is correct and efficient.