Application of nonlinear autoregressive neural network in predicting incidence tendency of hemorrhagic fever with renal syndrome / 中华流行病学杂志

Objective To explore the prospect of nonlinear autoregressive neural network in fitting and predicting the incidence tendency of hemorrhagic fever with renal syndrome (HFRS),in the mainland of China.Methods Monthly reported case series of HFRS in China from 2004 to 2013 were used to build both ARIMA and NAR neural network models,in order to predict the monthly incidence of HFRS in China in 2014.Fitness and prediction on the effects of these two models were compared.Results For the Fitting dataset,MAE,RMSE and MAPE of the ARIMA model were 148.058,272.077 and 12.678％ respectively,while the MAE,RMSE and MAPE of NAR neural network appeared as 119.436,186.671 and 11.778％ respectively.For the Predicting dataset,MAE,RMSE and MAPE of the ARIMA model appeared as 189.088,221.133 and 21.296％,while the MAE,RMSE and MAPE of the NAR neural network as 119.733,151.329 and 11.431％ respectively.Conclusion The NAR neural network showed better effects in fitting and predicting the incidence tendency of HFRS than using the traditional ARIMA model,in China.NAR neural network seemed to have strong application value in the prevention and control of HFRS.

Verification of dose parameters under reference and non-reference conditions for radiotherapy in Liaoning province / 中华放射医学与防护杂志

Objective To verify the reliability of dose parameters of radiotherapy under reference and non-reference conditions by using TLD.Methods Dose parameters were verified by using TLDs under reference and non-reference conditions,including the maximum dose in axel of 5 electron beams with energy of 9 MeV and the variations of dose by depth,source-skin distance,exposure field and 45° wedge for 10 photon beams with energy of 6 MV in 5 hospitals.Results The average relative deviation of 6 MV photon beam measured between TLDs and finger ionization chambers were 4.45％,within ± 7％ as required by IAEA.The average relative deviation of 9 MeV electron beam measured between TLDs and plane parallel chambers were 2.45％,within ± 5％ was required by IAEA.Conclusions Measuring dosimetric parameters by using TLDs under reference and non-reference conditions was reliable and feasible.

Epidemiological study on viral diarrhea during 2009-2011 in Liaoning Province / 中华传染病杂志

Objective To understand the epidemiologic characteristics and pathogenic virus of cases of viral diarrhea in sentinel hospitals in Liaoning Province.Methods From Jan 2009 to Dec 2011,639 stool samples from sentinel hospitals of Liaoning Province were collected.Rotavirus,human calicivirus,astrovirus and adenovirus were detected by polymerase chain reaction and reverse transcriptase-polymerase chain reaction.The data analysis used chi-squanetest and Fisher's exact test.Results Rotavirus,human calicivirus,astrovirus and adenovirus were detected in 15.96 ％,11.25 ％,1.25％ and 0.31％ of the 639 specimens,respectively.G3 was the most prevailing serotype and P[8] was the most common genotype among 101 group A rotavirus isolates.One strain of group C rotavirus was also detected,which was reported for the first time from Liaoning Province.Phylogenetic analysis showed that this group C rotavirus JX407109 in the present study had the closest genetic relationship with the outbreak strain AB648916 from Japan,with nucleotide sequence consistency of 99 ％.Among the 72 samples of human calicivirus,70 samples were norovirus with G Ⅱ/4 being the predominant genotype,and 2 samples were sapovirus.Astrovirus was detected in 8 samples,most of which were genotype 1.Adenovirus was detected in 2 samples,and both were genotype 41.High incidences of viral diarrhea were noted during the months from December to next year February,and children under 5 years of age had high incidence of rotavirus and astrovirus,while the incidence of calicivirus were similar among different age groups.Conclusions The predominant pathogens of viral diarrhea in Liaoning Province are group A rotavirus and calicivirus.Notably,the group C rotavirus in Liaoning Province shares high genetic consistency with the outbreak strain from Japan.

The impact of Japanese Fukushima nuclear accident on environmental radiation levels in some areas of Liaoning province / 中华放射医学与防护杂志

Objective To investigate the environmental impact of the Japanese Fukushima No.1 nuclear power plant accident on radiation levels in some areas of Liaoning province.Methods The emergent monitoring was performed by detecting atmosphere aerosols,precipitations,drinking water,vegetables,milk and seafood by gamma spectrometry analysis and gross activity measurements.Results The fission radionuclides of 131I,134Cs and 137Cs were detected in atmosphere aerosols 20 d after nuclear accident.The rad ionuclides of 131I,134Cs and 137Cs were found existing in atmosphere for 25,4 and 6 d,respectively,with the highest concentrations of 4.6 × 10 3,2.9 × 10-4 and 4.2 × 10-4 Bq/m3,respectively.The man-made fission radionuclides could not be detected in vegetablcs,drinking water and milk from Shenyang city and seafood from Dandong city.Conclusions The atmosphere might be slightly contaminated in Liaoning province due to the nuclear accident,whereas the vegetables,milk and drinking water not contaminated.

Baseline investigation on mortality from malignant tumor from 2006 to 2009 around Hongyanhe Nuclear Power Plant,Liaoning Province / 中华放射医学与防护杂志

objective To understand the baseline data of mortality from malignant tumor from 2006 to 2009 around Hongyanhe Nuclear Power Plant in Wafangdian City,Liaoning Province,so as to provide scientific basis for evaluating the impact of normal operation of nuclear power plant on the health of the residents nearby.Methods Thirty small towns near Hongyanhe Nuclear Power Plant were divided into 5 investigated areas according to the distances away therefrom(0.,10.,20-,30-,and 40-km).The data about from malignant tumor were obtained from the Center for Disease Control and Prevention of Wafangdian.The mortality distribution of difierent malignant tumors was analyzed,including the radiosensitive malignant tumors,especially leukemia,breast cancer,and thyroid gland cancer in different area,gender,and age groups.Results The mortality from malignant tumor was 151.97/105,and the standardized mortality rate(SMR)was 97.76/105.The mortality from malignant tumor among the males was 188.28/105(with the SMR of 116.76/105),and that among the females was 113.47/105(with the SMR of 75.89/105).with a sex ratio of 1.71.The first five cancers in the rank of death causes were lung,liver,stomach,colorectal,and esophageal cancers with mortality of 46.19/105,23.51/105,20.30/105,8.06/105 and 5.45/105,respectively.The mortality from mal.ignant tumor in the areas around the nuclear power plant from the near to the distant were 99.85/105, 137.40/105,138.73/105,156.30/105,and 154.16/105,respectively.The mortality from radiosensitive malignant tumors,leukemia,breast cancer,and thyroid gland cancer were 4.57/105,4.06/105,and 0.26/105,respectively.Conclusions Lung cancer and digestive tract malignant tumors are the main causes of death from malignant tumors in Wafangdian area before the nuclear power plant began to operate.There are no significant differences in the mortality distribution of malignant tumors among different areas,genders,and age groups.There are not significant differences in the mortality distribution of leukemia and breast cancer among different areas and age groups.