ABSTRACT
Objective To explore the application of time series autoregressive integrated moving average (ARIMA) based on seasonal difference to predict the number of syphilis cases in Anhui Province, and to provide a reference for early warning and control of syphilis. Methods Using R 3.6.2 software, the number of syphilis cases in Anhui Province from January 2004 to December 2016 was used for model fitting, and the resulting model was used to predict the incidence from January to December 2017. The difference between the predicted value and actual observed value was compared to evaluate the prediction effect of this model fitting. Results The incidence of syphilis in Anhui Province was on the rise with obvious periodicity. ARIMA(1,1,1)(0,1,2)12 was the optimal model, with the AIC being -264.81 and the BIC being -249.99. Box-Pierce test showed that λ2 value was 1.444(P=0.963), 10.459(P=0.576), and the difference was not statistically significant (P>0.05), indicating that the residual sequence was white noise. The model accuracy effect evaluation showed that the MAE was 0.06, the RMSE was 0.09, and the MAPE was 1.00%, indicating that the model fitting effect was good. The 2017 data was used to test the effect of the model extrapolation, and the results showed MAPE=6.09%, indicating that the model extrapolation effect was good. The actual value fell within 95% confidence interval of the predicted value, and the model prediction effect was relatively ideal. Conclusion The ARIMA(1,1,1)(0,1,2)12 model could better fit and predict the number of syphilis cases in Anhui Province, which may provide a theoretical basis for early warning, prevention and control of syphilis.
ABSTRACT
Objective To compare the advantages of three-dimensional(3D) and two-dimensional(2D) ultrasound in embryo transfer. Methods A total of 319 patients accepted embryo transfter were included in this study. 2D and 3D ultrasound were used to investigate the uterine cavity and transfer distance from the fundus (TDF),respectivly. They were divided into four groups according to TDF difference(D-TDF) between 2D and 3D ultrasound(group of DTDF<3mm,group of DTDF3～5mm,group of 6～9 mm,group of DTDF≥10 mm. Pregnancy outcomes among the four groups were compared. Results Of the 319 patients, 41 were observed to have abnormal uterine cavity. For 140 patients, the TDF measured by 2D ultrasound were different from that measured by 3D ultrasound. Clinical pregnancy rate and implantation rate were found lowest in group of TDF≥10 mm mm (7.7% vs 34.1%,38.1% ,40.0% and 3.6% vs 18.2% ,21.2% ,20.0%, P <0.05). Conclusions 2D ultrasound is limit and deficient for embryo transfer, especially for the visualization of uterine cavity and location of catheter tip, however, it may be better achieved with 3D ultrasound. It is helpful to use the 3D ultrasound to place the catheter tip accurately and improve the pregnancy rate of embryo transfer.