Objective To understand the status of indoor air formaldehyde pollution in a certain city in China.Methods 50 newly decorated houses in a certain city were chosen and the formaldehyde concentration in indoor air in different types of room were determined.Results The formaldehyde concentrations in indoor air in 56.6% of the investigated 50 houses exceeded the State Standard.And the highest concentration was 1.05 mg/m3 which was 10.5 times of the limit in the State Standard.Child's bedrooms were most seriously polluted,73% of which exceeded the State Standard.Conclusion The status of indoor air formaldehyde pollution in the newly decorated houses in a certain city in China is serious,this problem needs to be paid more attention to.

Objective To investigate the effects of the polluted organic substances in urban water environment and genetoxicity of the organic pollutants in drinking water on DNA damage in primary cultured hepatocytes in rats. Methods Qualitative analysis of the organic extracts from source water and drinking water in five waterworks in city C with GC/MS was conducted and the effects of organic extracts on DNA damage in primary cultured hepatocytes in rats were tested with single cell gel electrophoresis assay. Comet length means and percentage of tail cell were observed. Results A total of 98 organic pollutants were detected in all samples including 60 in source water and 58 in drinking water. The pollutants were mainly esters, ketons, phenols, benzenes and the derivatives. Comet length means was found to be significantly higher ( P

90%.Then the purified sertoli cells were treated with the toxicants at different dose,i.e.DBP(0.1,1,10,100,500 ?g/ml),BaP(0.01,0.1,1,10,50 ?g/ml)and their combination DBP+BaP(0.1+0.01,1+0.1,10+1,100+10,500+50 ?g/ml).The viability of sertoli cells was determined by MTT method and the lactate concentration in the cultured medium was detected.Results As compared with DMSO control,the absorbance values in 100 ?g/ml DBP and DBP+BaP(100+10 ?g/ml)groups were significantly increased(P0.05).Lactate concentration in 100,500 ?g/ml DBP groups,50 ?g/ml BaP group and DBP+BaP(100+10,500+50 ?g/ml)groups were increased(P

Objective To explain the physiological properties of serum leucine aminopeptidase (LAP) and discuss the different levels and clinical meaning of serum LAP during the second and the third trimester of gestation.Methods Rate turbidimetry was used to assay serum LAP activity of 175 pregnant women in the second trimester of gestation, among whom 162 were normal and 13 were intrahepatic cholestasis of pregnancy (ICP), and 302 pregnant women in the third trimester of gestation, among whom 215 were normal, 76 were ICP, 6 were pregnancy-induced hypertension syndrome and 5 were premature delivery, and 100 healthy or non-pregnant women.Results Serum LAP activity of pregnant women in the group of the second trimester of gestation was (140.43?64.39) U/L, in the group of the third trimester of the gestation was (234.72?93.53) U/L, and in control group was (72.62?15.31) U/L. The serum LAP activities of the two pregnant groups were much higher than that of control group (P

Objective To investigate the safety of trial of labor after cesarean (TOLAC) and clinical factors associated with successful TOLAC and to compare TOLAC with elective repeat caesarean section (ERCS) in terms of obstetric and neonatal outcomes.Methods A prospective cohort study was conducted among gravidas who had a history of lower segment cesarean section and were hospitalized in the Department of Obstetrics and Gynecology,the Affiliated Drum Tower Hospital of Medical School of Nanjing University from January to December 2014.Exclusion criteria included indications for caesarean section (such as placenta previa,placenta accreta,twin pregnancy,breech presentation and severe preeclampsia),serious maternal complications after cesarean section,lower uterine segment thinner than 3 mm and poor healing of uterine incision.Totally,287 gravidas were enrolled.Among them,142 chose TOLAC and the other 145 requested ERCS.Clinical data of those gravidas were collected and statistically analyzed by t-test,Log-rank test,Chi-square or Fisher's exact test.Results (1) The success rate of TOLAC was 90.8％ (129/142).There was no significant difference in maternal age,gestational age,thickness of lower uterine segment,interval between the two deliveries and neonatal birth weight and asphyxia rate between the successful (n=129) and unsuccessful (n=13) groups (all P＞0.05).Although the two groups had no significant difference in postpartum hemorrhage (PPH) rate,the gravidas who failed in TOLAC lost more blood than those who succeeded [425 (195-675) vs 200 (50-1 400) ml,P＜0.05].Moreover,higher amniotic fluid contamination rate was observed in the unsuccessful group [6/13 vs 17.1％ (22/129),P＜0.05].In the TOLAC group,99.3％ (141/142) were under continuous fetal heart rate monitoring.Incomplete uterine rupture occurred in one women without serious maternal or neonatal outcomes.The reasons for 13 failed TOLAC cases were unbearable pain during labor,abnormal labor,fetal distress and threatened rupture of uterus.(2) Compared with the ERCS group,the TOLAC group showed shorter interval from last cesarean section to the indexed delivery[5 (2-18) vs 6 (2-19) years],younger maternal age [(31±4) vs (33 ±4) years old] and less blood loss [200 (50-1 400) vs 300 (100-1 500) ml] (all P＜0.05).Conclusion Our study shows that,those who preferred TOLAC were younger,or had shorter pregnancy interval from last cesarean section.The success rate of TOLAC is high for women undergoing systematic prenatal assessment and close management during labor with less blood loss and non-serious maternal and neonatal complications compared with ERCS.

Objective To explore the blood lead level and its relationship with behavior in school?age children from rural areas of Chongqing. Methods A total of 697 students from grades 3 to 6 in the fall semester of 2014 from 14 rural townships in one district of Chongqing was selected by using the random cluster sampling method. Blood were sampled to analyze the lead level. Neurobehavioral tests were performed to determine their personal cognitive and memory ability. Questionnaires and physical examinations were administered to obtain the information of confounding factors. All students were divided into Q1-Q4 groups according to the quartile of their blood lead level. The relationship between the blood lead level and behavior was analyzed by multivariate logistic regression model and restricted spline regression model. Results The mean age of 697 students was (10.07±1.36) years old, and the median (interquartile range) of their blood lead level was 44.31 (35.42) μg/L. Multivariate logistic regression model showed that after adjusting for age, gender, body mass index and maternal culture level, compared with Q1 group, the OR (95%CI ) values of high digit symbol substitution test (DSST) scores and high overall memory quotient (MQ) scores in Q 3 group were 1.65 (1.01-2.70) and 2.10 (1.21-3.62), and the OR (95%CI ) value of high long term memory (LTM) scores in Q4 group was 0.53 (0.31-0.92). The results of the restricted spline regression model showed that the dose?response curves between the blood lead level and MQ/LTM test scores were both parabolic (P<0.05). Conclusion The blood lead level of school?age children from rural areas of Chongqing is the same as that from other areas of China, but slightly higher than that from other areas of Chongqing. Children with higher blood lead level have poor long?term memory ability.

Objective To explore the blood lead level and its relationship with behavior in school?age children from rural areas of Chongqing. Methods A total of 697 students from grades 3 to 6 in the fall semester of 2014 from 14 rural townships in one district of Chongqing was selected by using the random cluster sampling method. Blood were sampled to analyze the lead level. Neurobehavioral tests were performed to determine their personal cognitive and memory ability. Questionnaires and physical examinations were administered to obtain the information of confounding factors. All students were divided into Q1-Q4 groups according to the quartile of their blood lead level. The relationship between the blood lead level and behavior was analyzed by multivariate logistic regression model and restricted spline regression model. Results The mean age of 697 students was (10.07±1.36) years old, and the median (interquartile range) of their blood lead level was 44.31 (35.42) μg/L. Multivariate logistic regression model showed that after adjusting for age, gender, body mass index and maternal culture level, compared with Q1 group, the OR (95%CI ) values of high digit symbol substitution test (DSST) scores and high overall memory quotient (MQ) scores in Q 3 group were 1.65 (1.01-2.70) and 2.10 (1.21-3.62), and the OR (95%CI ) value of high long term memory (LTM) scores in Q4 group was 0.53 (0.31-0.92). The results of the restricted spline regression model showed that the dose?response curves between the blood lead level and MQ/LTM test scores were both parabolic (P<0.05). Conclusion The blood lead level of school?age children from rural areas of Chongqing is the same as that from other areas of China, but slightly higher than that from other areas of Chongqing. Children with higher blood lead level have poor long?term memory ability.

Objective:To discuss the design details of accelerator room for a novel enclosed O-ring linac Halcyon, and to optimize its protection and layout.Methods:According to the optimization principle of radiation protection and the requirements of national radiation protection standards, and the structural characteristics of Halcyon accelerator, the differences between conventional and this novel accelerator rooms were analyzed by discussing the space layout of the machine room, shielding calculation, electrical facilities, purifying ventilation, temperature and humidity control and other factors.Results:The Halcyon machine had a compact structure, a closed ring frame design and a main beam shielding device, which could greatly reduce the radiation protection pressure while improving the space utilization rate of the machine room. The optimized design layout of the machine room could eliminate hidden dangers, avoid design defects, and prevent adverse consequences caused by design errors.Conclusions:The overall structure of Halcyon accelerator is different from that of conventional accelerators. The design details should be taken into full consideration to ensure the optimization of radiation protection, lay a good foundation for subsequent installation, debugging and operation of the equipment and create a good treatment environment for patients and medical staff.

Objective:To study the clinical feasibility and advantages of the RapidPlan module based on Halcyon 2.0 ring medical linear accelerator in the design of volumetric modulated arc therapy (VMAT) plans after cervical cancer surgery.Methods:The data of 98 clinical cervical cancer cases were selected from the database, and VMAT artificial radiotherapy plans were designed based on Halcyon 2.0. Then, the designed plans were imported into the RapidPlan module to train the module for a prediction model with high goodness of fit. Another 20 patients after cervical cancer surgery were selected as the validation set to compare the differences in dosimetry, plan consistency, and plan execution efficiency between the manual plans and RapidPlan automatic plans.Results:The RapidPlan automatic plans could obtain dose distribution of target volume and organs at risk with the same quality as the manual plans. The RapidPlan automatic plans provided slightly inferior protection of the femoral head but superior protection of the spinal cord compared to the manual plans, and the difference was statistically significant ( t = 4.71, P<0.001). The average MU of the RapidPlan automatic plans was 687.46, which was lower than that of the manual plan (815.34), and the difference was statistically significant ( t = 6.09, P < 0.05). The portal dosimetry (PD) verification revealed that the average γ passing rate (1 mm/1%) of the RapidPlan automatic plans was 89.48%and that of the manual plans was 88.22%, and the difference was statistically significant ( t = 3.35, P < 0.05). Conclusion:RapidPlan automatic plans based on the Halcyon 2.0 platform can meet the clinical needs of the VMAT program for cervical cancer and has certain advantages.

Objective To explore and establish accurate detection quality control method of source positioning and timer precision for afterloading equipment. Methods The source positioning detection device was made of hd camera,EBT3 disposable film and steel rule,collecting source in each resident point for video images and film. Accurate measurement of radioactive source positioning and timer accuracy, including the timing absolute error and linear error through analysis of image sampling rate. After the film grayscale distribution analysis,comparison between film gray peak position and the measurement of resident point geometry,got the stay point source physics and radiation center deviation. Results Radioactive source physics and radiation center deviation was (-0.33± 0. 10) mm;For all default dwell time,timer average absolute deviation was (0.22±0. 02) s,linear fitting result was y=x-0. 226,R2=1,timing linear error was-0. 01％ Conclusions established detection means through the video images and film exposure quantitative analysis for accurately determination of source positioning,dwell time and source radiation center precision. After experimental testing the machine precision satisfied the requirement of clinical use.