ABSTRACT
Objective Using the Back Propagation (BP) Neural Network Model to discover the relationship between meteorological factors and mortality of intracerebral hemorrhage,to provide evidence for developing an intracerebral hemorrhage prevention and control program,in Harbin.Methods Based on the characteristics of BP neural network,a neural network Toolbox of MATLAB 7.0 software was used to build Meteorological data of 2007-2009 with intracerebral hemorrhage mortality to predict the effect of BP neural network model,and to compare with the traditional multivariate linear regression model. Results Datas from the multivariate linear regrcssion indicated that the cerebral hemorrhage death mortality had a negative correlation with maximum temperatureand minimum humidity while having a positive correlation with the average relative humidity and the hours of sunshine.The linear correlation coefficient of intracerebral hemorrhage mortality was 0.7854,with mean absolute percentage (MAPE) as 0.21,mean square error (MSE) as 0.22,mean absolute error(MAE) as 0.19.The accuracy of forecasting was 81.31％ with an average error rate as 0.19.The Fitting results of BP neural network model showed that non-linear correlation coefficient of intracerebral hemorrhage mortality was 0.7967,with MAPE as 0.19,MSE as 0.21,MAE as 0.18.The forecasting accuracy was 82.53％ with the average error rate as 0.17.Conclusion The BP neural network model showed a higher forecasting accuracy when compared to the multiple linear regression model on intraccrebral hemorrhage mortality,using the data of 2010' s.
ABSTRACT
Objective To explore the effects of different vitamin A(VA) levels on thyroid cells apoptosis and its gene expression of mice taking excessive iodine. Methods Kunming mice were randomly divided into 6 groups according to body weight 3 weeks after born: normal control(NI) group, high iodine(HI) group, low vitamin (LVA) group, high iodine plus low vitamin A(HI+LVA) group, high iodine plus vitamin A1 (HI+VA1) group, high iodine plus vitamin A2(HI+VA2) group. The VA was given in food(4000,4000,0,0,8000,16 000 U/kg), and the iodine was given as potassium iodate in water (I-:50,3000,50,3000,3000,3000 μg/L). The apoptosis was tested using in situ end labehng(TUNEL) method. Reverse transcription polymerase chain reaction (RT-PCR) were used to measure the level of mRNA of apoptosis gene(Fas, FasL, Bcl-2) in tissues. Results Apoptotic index measured by TUNEL method was rising along with the mice age. Compared to NI group[(14.09±5.68)%], apoptotic index was significantly increased in HI[(20.91±9.57)%], HI+LVA[(20.29±9.90)%]and HI+VA2 [(19.51±8.25)%]groups in the three months(P < 0.05). Compared to NI group[(16.80±9.90)%], apoptotic index was significantly increased(P < 0.05) in HI[(23.22±8.58)%],LVA[(22.56±6.17)%],HI+LVA [(25.99±9.62)%],HI+VA1 [(21.65±7.74)%]groups in the six months. Compared with the NI group(Fas: 1.29±0.25,1.27±0.26; FasL: 1.60±0.13,1.65±0.13), the mRNA levels of Fas and FasL in HI group(Fas: 1.57±0.36,1.49±0.35; FasL: 1.85±0.46,1.84±0.32) were increased, but the differences were not remarkable(P > 0.05) in the three and six months. Compared with the HI group, the mRNA levels of Fas in HI+ VA1, HI+VA2(1.33±0.35, 1.30±0.26) groups were decreased to the level in NI group in the six months. The mRNA levels of Fas and FasL were not different (P > 0.05) between HI+LVA(I.60±0.27,1.88±0.46) and HI groups in the three months. The mRNA levels of Bcl-2 were not remarkably differences in the three months (1.05±0.19,0.96±0.33,0.95±0.26,1.18±0.27,1.10±0.19,0.98±0.36, all P > 0.05), and in the six months (1.35±0.28,1.60±0.25,1.48±0.18,1.71±0.26,1.66±0.29,1.56±0.35, all P > 0.05). Conclusions Excessive iodine can cause thyroid cells apoptosis in mice. Supplementation of suitable amount of VA can regulate the levels of the apoptosis-related genes expression, and partly antagonize the apoptosis caused by high iodine.