ObjectiveTo explore the possible mechanisms of Shoutai Wan （寿胎丸） in treating recurrent miscarriage （RSA） from the perspective of immune tolerance under the acidic microenvironment at the maternal-fetal interface. MethodsFemale CBA/J mice were randomly divided into normal group， model group， progesterone group， and Shoutai Wan group， with 15 mice in each group. The mice in the normal group and model group were given 0.2 ml distilled water by gavage each day， the Shoutai Wan group given Shoutai Wan decoction 0.15 g/（10 g·d） by gavage， the progesterone group given progesterone tablets 0.44 mg/（10 g·d） by gavage. After gavage for 14 days， the mice were cohabited. Female CBA/J mice in the normal group were mated with male BALB/c mice at a ratio of 2∶1， and female CBA/J mice in the other groups were mated with male DBA/2 mice at a ratio of 2∶1 to establish the RSA mouse model. Vaginal smears were taken from the female mice the next morning， and the appearance of a large number of spermatozoa and the presence of a vaginal plug were considered as the first day of pregnancy. After the appearance of the plug， the mice were continued to be administered according to the previous method until the 10th day of pregnancy. On the 10th day of pregnancy， maternal-fetal interface tissues were collected from each group of mice， and lactate dehydrogenase colorimetric method was used to detect lactate （LA） content； qPCR method and Western blot method were used to detect the expression of immune-related factors interleukin-4 （IL-4）， interferon-gamma （IFN-γ）， transforming growth factor beta 1 （TGF-β1）， and forkhead box protein 3 （Foxp3） mRNA and protein； flow cytometry was used to detect the numbers of helper T lymphocyte 1 （Th1）， helper T lymphocyte 2 （Th2）， regulatory T cell （Treg）， classical macrophage （M1）， and alternative macrophage （M2）. The bivariate Pearson test was used to analyze the correlation between LA content and the numbers of Th1， Th2， Treg， M1， and M2 cells， as well as the correlation between LA content and the expression of IL-4， IFN-γ， TGF-β1， Foxp3 protein， and mRNA. ResultsOn the 10th day of pregnancy， compared with the normal group， the LA content decreased in the model group， and the expression of IL-4， TGF-β1， Foxp3 protein and mRNA in the maternal-fetal interface tissues decreased， while the expression of IFN-γ protein and mRNA increased. The numbers of Th1 and M1 cells increased， while the numbers of Th2， Treg， and M2 cells decreased （P＜0.05 or P＜0.01）. Compared with the model group， the LA content increased in the Shoutai Wan group and progesterone group. The expression of IL-4， TGF-β1， Foxp3 protein and mRNA in the maternal-fetal interface tissues increased， while the expression of IFN-γ protein and mRNA decreased. The numbers of Th1 and M1 cells decreased， while the numbers of Th2， Treg， and M2 cells increased （P＜0.05 or P＜0.01）. The LA content was positively correlated with the numbers of Th2， Treg， and M2 cells， and the expression of IL-4， TGF-β1， Foxp3 protein， and mRNA （P＜0.05 or P＜0.01）； the LA content was negatively correlated with the numbers of Th1， M1 cells， and the expression of IFN-γ protein and mRNA （P＜0.05 or P＜0.01）. ConclusionShoutai Wan may improve immune tolerance by regulating the expression of immune-related factors in the acidic microenvironment at the maternal-fetal interface of RSA model mice， thereby exerting its role in preventing miscarriage.

Objective:To describe the characteristics, etiology and patterns of outpatients and inpatients patients with moderate or severe valvular heart disease (VHD).Methods:This is a cross-sectional study. Outpatients and inpatients with moderate or severe VHD who underwent transthoracic echocardiography for first examination from 1 st January 2001 to 1 st January 2020 in Southwest Hospital, Army Medical University were enrolled. Data were collected from medical records and big data platform of Southwest Hospital. Characteristics of age and gender, etiology and types of VHD were descriptively analysed. Results:A total of 68 354 patients with moderate or severe VHD were enrolled. The age was 63 (50, 72) years. And 35 706 (52.24%) patients were female. (1) Age characteristics: There was similar age trend between male and female patients with moderate or severe VHD. The number of patients increased firstly and then decreased and reached its peak in the age group of 65-69 years old. The peak age of mitral stenosis patients was 45-49 years, which was earlier than that of whole patients with moderate or severe VHD. The median age of patients with bicuspid aortic valve was 42 years. (2) Gender characteristics: The proportion of tricuspid regurgitation, pulmonary regurgitation, mitral regurgitation, mitral stenosis and valve surgery in female patients with moderate or severe VHD were higher than those in male patients. The proportion of aortic regurgitation, aortic stenosis and bicuspid aortic valve in male patients with moderate or severe VHD were significantly higher than those in female patients (all P<0.05). (3) Etiology: The proportion of rheumatic VHD was 13.07% (8 934/68 354), which was higher than that of degenerative VHD (0.67% (458/68 354)). (4) Types of VHD: Tricuspid regurgitation made contribution to the largest proportion with 60.72% (41 503/68 354), followed by mitral regurgitation, aortic regurgitation, mitral stenosis, pulmonary regurgitation and aortic stenosis. Conclusions:There are certain regional characteristics in the prevalence of moderate or severe VHD in southwest China, suggesting different attention should be paid on the whole process of refined management of moderate or severe VHD.

Objective Tto analyze the spatial distribution and characteristics of the national AIDS/HIV epidemics from 2009 to 2020 to discover its distribution, aggregation, and hot spots, and provide corresponding suggestions for AIDS prevention and control. Methods Spatial autocorrelation analysis, hot spot analysis, and Kriging interpolation prediction were used to describe, analyze, and predicting the spatial distribution of AIDS epidemics across the country. Results The national AIDS incidence and mortality rate increased yearly, but the growth rate shows a downward tendency with uneven spatial distribution,focusing on the southwest and northwest regions; the average annual incidence rate of AIDS ( Moran's I> 0, P < 0. 01) and the average annual mortality rate (Moran's I> 0, P < 0. 01) of the distribution had a positive global spatial correlation, with Sichuan, Yunnan, Guangxi, Chongqing,Hunan and Guizhou being the areas with ^“high-high^” clusters of AIDS incidence; Sichuan, Yunnan, Guangxi,Hunan,Xinjiang and Guizhou were the areas with ^“high-high^” clusters of average annual mortality. The ^“hot spot^” areas were mainly concentrated in the southwestern part of China, and the ^“cold spot^” areas were mainly concentrated in the eastern coastal and northern parts of China; Kriging interpolation predicted that Xinjiang would be the new hot spot area for future epidemics. Conclusion The spatial distribution of AIDS in China is uneven, showing spatial aggregation, hot spots and cold spots coexist, and the high-risk areas will continue to expand in the future.So the prevention and control work should be carried out in a targeted and localized manner.

Objective To explore the effect of coronavirus disease 2019 (COVID-19) on the frequency of chest CT scan. Methods A retrospective study was conducted to extract information on the number of outpatient, emergency, and inpatient visits and patients who had chest CT imaging examination from January 1 to December 31, 2020 and in the same period in 2019 through the hospital’s medical data platform for analysis, and the chi-square test was used to analyze whether the difference in the proportion of patients who had chest CT imaging examination between 2019 and 2020 was statistically significant. Results The proportion of outpatients and emergency patients with chest CT examination was significantly higher in 2020 than in 2019 (2.48% vs 1.47%, χ² = 581.7, P < 0.000). The proportion of inpatients who underwent chest CT examination was significantly higher in 2020 than in 2019 (35.47% vs 28.01%, χ² = 182.0, P < 0.000). Conclusion Under the COVID-19 epidemic, the proportion of chest CT examination in this hospital in 2020 shows a significant upward trend compared with the same period in 2019, which will increase the collective dose due to medical exposure, and the hospital should pay attention to the determination of the legitimacy of chest CT scan.

Objective To investigate the dose of radiation in children under going X-ray-guided air enema reduction, and to provide a basis for reducing the risk of radiation injury in pediatric patients. Methods Data were collected from children with intussusception who were treated with air enema. The experimental conditions of high, medium, and low doses of three age groups were analyzed. Phantoms were used to simulate the operation, and the radiation dose was measured using a thermoluminescence system. Results In children with intussusception, the success rate of air enema under the guidance of X-ray was 88% (including secondary intussusception), with anearly re-intussusception rate of 8%. The effective dose of treatment ranged from 0.57 to 12.33 mSv, and the tissues and organs with high absorbed dose were mainly in the chest and abdomen. Conclusion Children in different groups are exposed to significantly differentand relatively high doses. The operators are recommended to use ultrasonic guidance. With X-ray guidance, the exposure time should be minimized and protective equipment for children should be used.

Objective:To understand the activity concentration of 131I aerosol in the air of the iodine treatment workplace and estimate the internal dose of 131I inhaled by medical staff in nuclear medicine. Methods:Using CF-1001BRL portable large capacity air sampler, the 131I aerosol in the iodine treatment workplace of nuclear medicine department of 6 hospitals in Shandong province was collected by iodine box, and the HPGe-γ energy spectrometer was used to measure the samples. The 131I activity concentration in iodine treatment workplace at 6 hospitals was obtained, and the internal dose to medical staff was estimated. Results:The 131I activity concentration in the air in iodine treatment workplaces at 6 hospitals ranged from 3.64 to 2.94×10 3 Bq/m 3. The 131I activity concentration in the controlled area (ward, patient passageway, subpacking room, operation administration room) was significantly higher than that in the supervised area. The highest 131I activity concentration, 2.62×10 2 Bq/m 3, in the supervised area was found in the medical care passageway. The estimated effective dose to nuclear medicine workers was 0.07-5.68 mSv, not exceeding the national limit. Conclusions:The phenomenon of 131I aerosol contamination still exists in the iodine treatment workplaces of nuclear medicine departments in hospitals, so it is necessary to carry out internal radiation monitoring for nuclear medicine departments all around the country, and explore more reasonable protection standards and methods.

Objective By measuring the induced radioactivity of the medical electron linear accelerator, and analyzing the measuring results and the measuring process, the cooling law of the induced radioactivity was studied, to provide basic data for evaluating additional doses to patients, medical staff and the public. Methods Five Medical Electron Linear accelerators were used to measure the induced radioactivity by using automes-6150AD6/H+6150AD-b/H x-γ radiation peripheral dose equivalent rate meter for environmental monitoring. Results The level of induced radioactivity of 5 medical electron linear accelerators is related to the factors such as measuring position and time: 10 second after the end of beam output, the maximum dose equivalent rate is 5.55 μSv/h around 5 cm on the surface of the head housing of the accelerator, and the maximum ambient dose equivalent rate at 1 m from the fixed point of the housing is 4.07 μSv/h, 5 minutes after the end of output, the maximum dose equivalent rate is 2.11 μSv/h around the 5 cm surface and 1.77 μSv/h around the 1 m fixed point. Conclusion The measured radioactivity induced by the medical electron linear accelerator gradually cools over time, the measurement valuesare maintained in a relatively fixed range, and the fluctuation range of the values is narrow.

Objective: To estimate the doses to patients from ERCP operation through experimental measurements. Methods: A retrospective analysis was made of 56 ERCP operations in three hospitals, and meanwhile, the tube voltage and current, fluoroscopy time, accumulated doses, DAPs (dose-area product) and photographic frames were also recorded for statistical analysis. Three cases of RECP operation that had led to high, medium and low DAP values were selected, respectively, as high, medium and low dose groups based on anthropomorphic phatom (AP). ERCP operation was simulated on AP on the basis of putting TLDs in it. The absorbed doses of organs were measured while effective doses while calculated. Results: The effective doses for high, medium and low groups were 2.69, 11.52 and 39.27 mSv, respectively. The effective dose was 14 times higher in high dose group than that in low group. The highest organ doses for three groups were all concentrated in the irradiation fields. Conclusions Organ doses from ERCP phantom experiments vary largely in different groups. Compared with phantom experiments of other interventional types, ERCP can be regarded as one of interventional means leading to high-dose. It is advisable to reasonably and safely use intervention diagnosis and therapy and in order optimize radiation doses to patients.

Objective:To observe the clinical features of retinopathy of prematurity (ROP) in multiple fetuses.Methods:Retrospective clinical study. From December 2009 to June 2018, 758 premature or low-weight multiple fetuses (multiple fetuses group) and 2363 simultaneous single fetuses (single fetuses group) who were admitted to the Department of Ophthalmology and Neonatal Department of Dongguan People’s Hospital and underwent ROP screening were included in the study. Among the multiple pregnancy group, there were 735 twins and 23 triplets; 441 males and 317 females. The mean gestational age was 32.22±2.14 weeks, and the mean body weight was 1.69±0.43 kg. There were 202 of natural births and 556 of cesarean sections. A total of 750 cases have a history of oxygen. Among the singleton group, 1421 were males and 942 were females. The mean gestational age was 32.06±2.52 weeks, and the mean body weight was 1.70±0.46 kg. There were 1146 of natural births and 1217 of cesarean sections. A total of 2333 cases have a history of oxygen. The detection rate of multiple ROP, gestational age, birth weight, sex composition ratio, mode of birth, time of first ROP diagnosis, and severity of ROP were observed. χ2 test was used to compare the rate between groups, and t test was used to compare the mean between groups. Results:Among the multiple pregnancy group, there were 68 cases (8.97%) of ROP. Among them, 64 twins (8.71%, 64/735), 4 triplets (17.39%, 4/23). Among the singleton group, there were 187 cases (7.91%) of ROP. With the increase of fetal number, the detection rate of ROP increased, but there was no significant difference ( χ2=3.097, P=0.213). There was no significant difference in the detection rate of ROP between multiple fetuses and single fetuses ( χ2=0.855, P=0.355). There was no significant difference in sex ratio ( χ2=0.069), mode of production ( χ2=1.900), birth weight ( t=0.139), gestational age ( t=-0.478), and time of first ROP diagnosis ( t=0.371) between ROP cases of multiple fetuses and single fetuses ( P=0.793, 0.168, 0.889, 0.633, 0.371). There was no significant difference in the constituent ratio of severity of ROP lesions between multiple fetuses and single fetuses ( χ2=3.003, P=0.223). Conclusion:There is no significant difference in ROP incidence, gestational age, birth weight, diagnosis time and severity of ROP between multiple fetuses and single fetuses under the same conditions.

A novel RNA virus, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is responsible for the ongoing outbreak of coronavirus disease 2019 (COVID-19). Population genetic analysis could be useful for investigating the origin and evolutionary dynamics of COVID-19. However, due to extensive sampling bias and existence of infection clusters during the epidemic spread, direct applications of existing approaches can lead to biased parameter estima-tions and data misinterpretation. In this study, we first present robust estimator for the time to the most recent common ancestor (TMRCA) and the mutation rate, and then apply the approach to analyze 12,909 genomic sequences of SARS-CoV-2. The mutation rate is inferred to be 8.69 × 10-4 per site per year with a 95％ confidence interval (CI) of [8.61 × 10-4, 8.77 × 10-4], and the TMRCA of the samples inferred to be Nov 28, 2019 with a 95％ CI of [Oct 20, 2019, Dec 9, 2019]. The results indicate that COVID-19 might originate earlier than and outside of Wuhan Seafood Market. We further demonstrate that genetic polymorphism patterns, including the enrichment of specific haplotypes and the temporal allele frequency trajectories generated from infection clusters, are similar to those caused by evolutionary forces such as natural selection. Our results show that population genetic methods need to be developed to efficiently detangle the effects of sampling bias and infection clusters to gain insights into the evolutionary mechanism ofSARS-CoV-2. Software for implementing VirusMuT can be downloaded at https://bigd.big.ac.cn/biocode/tools/BT007081.