Objective To investigate and design a coincidence detection system for an all-digital small animal PET scanner and evaluate its preliminary performance properties.Methods This coincidence module adopted a coincidence identification mode based on singles data in list-mode.Using digital signal processing technology,energy calibration,crystal identification,timing alignment and coincidence events extraction were performed on singles data in list-mode.The obtained data could be used for image reconstruction.Results The 13 × 13 crystal array was well recognized by the position histogram of one lutetium yttrium orthosilicate (LYSO) crystal block.In the coincidence timing histogram of the micro-Derenzo phantom,1.36 ns full width at half maximum was obtained.The rods with a diameter of 1.2 mm were clearly displayed in the reconstructed image of the micro-Derenzo phantom.Conclusion The coincidence module can provide satisfactory performance to meet the design needs of an all-digital small animal PET scanner.

Objective:To systematically analyze the IgG seroprevalence of mumps virus (MuV) in Chinese healthy population, and evaluate the immune effect based on the immunization strategy and the incidence of mumps in China.Methods:The databases of Wanfang data knowledge service platform, China National Knowledge Infrastructure, SinoMed, PubMed, and Web of Science were searched to retrieve literature about the level of MuV IgG antibody in Chinese healthy population from January 1, 2000, to March 31, 2022. The quality of eligible papers was appraised by using the cross-sectional study evaluation tool from Joanna Briggs Institute. Data analysis, including the stratified analysis of the IgG seroprevalence in different generations, regions, gender, immunization status, and age groups, was performed using R 4.1.2 and Stata 16.0.Results:A total of 69 papers (66 in Chinese and 3 in English) were included, involving 97 034 people in 26 administrative regions across China. The results showed that the MuV IgG seroprevalence in Chinese healthy population was 74.87% (95% CI: 71.41%-78.17%) and increased over time according to the cumulative Meta-analysis. The geometric mean concentration of antibody was 177.83 U/ml. The subgroup analysis showed that the positive rate of MuV IgG antibody increased with the age and vaccination doses. The positive rate of antibody in children aged from 0 to 17 months was only 32.42% (95% CI: 25.96%-38.88%). The highest positive rate was reported in North China, about 81.45% (95% CI: 75.76%-87.14%). In addition, the positive rate of MuV IgG antibody in urban population was higher than that in rural population ( P<0.01) and the positive rate of MuV IgG antibody in women was higher than that in men ( P<0.01). Conclusion:Since the vaccine was included in the expanded immunization program, the positive rate of mumps antibody in China has increased, and the antibody level varies in different regions and populations. It is still necessary to improve the MuV antibody level in Chinese healthy population, so as to better prevent and control the mumps epidemic in the future.

Objective:To systematically analyze the IgG seroprevalence of mumps virus (MuV) in Chinese healthy population, and evaluate the immune effect based on the immunization strategy and the incidence of mumps in China.Methods:The databases of Wanfang data knowledge service platform, China National Knowledge Infrastructure, SinoMed, PubMed, and Web of Science were searched to retrieve literature about the level of MuV IgG antibody in Chinese healthy population from January 1, 2000, to March 31, 2022. The quality of eligible papers was appraised by using the cross-sectional study evaluation tool from Joanna Briggs Institute. Data analysis, including the stratified analysis of the IgG seroprevalence in different generations, regions, gender, immunization status, and age groups, was performed using R 4.1.2 and Stata 16.0.Results:A total of 69 papers (66 in Chinese and 3 in English) were included, involving 97 034 people in 26 administrative regions across China. The results showed that the MuV IgG seroprevalence in Chinese healthy population was 74.87% (95% CI: 71.41%-78.17%) and increased over time according to the cumulative Meta-analysis. The geometric mean concentration of antibody was 177.83 U/ml. The subgroup analysis showed that the positive rate of MuV IgG antibody increased with the age and vaccination doses. The positive rate of antibody in children aged from 0 to 17 months was only 32.42% (95% CI: 25.96%-38.88%). The highest positive rate was reported in North China, about 81.45% (95% CI: 75.76%-87.14%). In addition, the positive rate of MuV IgG antibody in urban population was higher than that in rural population ( P<0.01) and the positive rate of MuV IgG antibody in women was higher than that in men ( P<0.01). Conclusion:Since the vaccine was included in the expanded immunization program, the positive rate of mumps antibody in China has increased, and the antibody level varies in different regions and populations. It is still necessary to improve the MuV antibody level in Chinese healthy population, so as to better prevent and control the mumps epidemic in the future.

Objective: To investigate the immunity to mumps after administrating measles-mumps-rubella vaccine (MMR) among children aged 2-7 years old in Jiangsu province in 2015. Methods: A total of 4 190 healthy children aged 2-7 years old, living in local places for at least 3 months, and having been vaccinated at least 1 dose MMR were recruited to the study from Wujin district of Changzhou city, Gaogang district of Taizhou city and Ganyu district of Lianyungang city by using stratified cluster random sampling method between September and November, 2015. Those who did not accept MMR vaccination, who refused venous blood collection, who had affected mumps according to the memory of parents or teachers and who were diagnosed serious disease by clinical doctors were excluded from study. The self-designed questionnaire was used to collect the general information of the subjects and their MMR immunization history; and 0.5-2.0 ml of venous blood was collected from each subject. ELISA was used to detect the mumps antibody level in the serum of patients. Positive was defined as the antibody level ≥108 mU/ml, and negative as <108 mU/ml. χ² test was used to compare the difference in positive rates among subjects; and analysis of variance was used to compare the GMC changes in different time points after MMR vaccination. Results: Among 4 190 children, 2 280 were males (54.42%) and 1 910 were females(45.58%), and the positive rate of IgG antibody was 81.38% (3 344). There were 3 156 (95.18%) children vaccinated with one dose MMR, 187 (4.80%) children with two dose MMR, and 1 (0.02%) child with three dose MMR. The difference in positive rate of IgG antibody among different aged subjects showed statistical significance (χ²=58.61, P<0.001), the highest positive rate was in group of subjects aged 4-5 years old, at 89.43% (406/454), while the lowest positive rate was found among subjects aged 6-7 years old, at 75.63% (1 648/2 179). The positive rate after one dose of MMR vaccination was 79.14% (3 156/3 988), significantly less than it after two doses (93.03%, 187/201) (χ²=22.93, P<0.001). The GMC level at years<1, 1-<2, 2-<3, 3-<4, ≥4 following one dose MMR in the 3 988 children was 152.47, 227.78, 167.08, 126.91, 79.43 mU/ml, whose difference was statistically significant (F=51.29, P<0.001). Conclusion The sero-prevalence of IgG antibody in the children aged 2-7 years old in Jiangsu province was high. The positive rate among who received two doses MMR was significantly higher than it among who received just one dose, and the GMC level waned with times.