Background ¹³⁷Cs in atmospheric aerosol is the product of past nuclear weapon tests and nuclear accidents. When ¹³⁷Cs is released into the atmosphere, it will deposit in dry land and marine environment, causing pollution of soil surface, water, agricultural products, and animal byproducts, and affecting public health. Objective To identify the variation pattern of ¹³⁷Cs activity concentration in aerosol and its correlation with dust concentration in Beijing area from 2017 to 2020. Methods A total of 958 aerosol samples were collected from November 1, 2017 to June 30, 2020 in Beijing with a high volume air sampler at a sampling flow rate about 600 m³·h⁻¹ and a collection time for each sample about 24 h. The activity concentration of ¹³⁷Cs in the aerosol samples was determined with a low-background high-purity germanium γ spectrometer. The dust concentration was calculated using the difference in the mass of the aerosol filter before and after sampling. The detection rate of ¹³⁷Cs and dust concentration in different seasons were compared. Spearman rank correlation test was used to analyze the correlation between ¹³⁷Cs activity concentration and dust concentration. Results From 2017 to 2020, the ¹³⁷Cs activity concentrations of 33 from 958 aerosol samples in Beijing were above the minimum detectable activityconcentration, the overall detection rate of ¹³⁷Cs was 3.4%, and the activity concentration ranged from 1.86 to 45.53 μBq·m⁻³, with a median value of 4.85 μBq·m⁻³. The detection rate of ¹³⁷Cs was highest in spring, followed by autumn, and lowest in winter and summer (8.4%, 3.0%, 1.1%, and 0.5%, respectively). The dust concentration ranged from 0.03 to 1.55 mg·m⁻³, with an average value of 0.18 mg·m⁻³. There was a statistically significant difference in the dust concentrations in spring, summer, autumn, and winter (F=45.51, P<0.05), and the highest value was 0.24 mg·m⁻³ in spring (P<0.05). The ¹³⁷Cs activity concentration was positively correlated with the dust concentration (P<0.05). Conclusion The ¹³⁷Cs activity concentration in aerosol in Beijing from 2017 to 2020 fluctuates within the range of background level, and its activity concentration is highest in spring, followed autumn, and lowest in summer and winter.

In this study, a single base editing system was used to edit the FecB and GDF9 gene to achieve a targeted site mutation from A to G and from C to T in Ouler Tibetan sheep fibroblasts, and to test its editing efficiency. Firstly, we designed and synthesized sgRNA sequences targeting FecB and GDF9 genes of Ouler Tibetan sheep, followed by connection to epi-ABEmax and epi-BE4max plasmids to construct vectors and electrotransfer into Ouler Tibetan sheep fibroblasts. Finally, Sanger sequencing was performed to identify the target point mutation of FecB and GDF9 genes positive cells. T-A cloning was used to estimate the editing efficiency of the single base editing system. We obtained gRNA targeting FecB and GDF9 genes and constructed the vector aiming at mutating single base of FecB and GDF9 genes in Ouler Tibetan sheep. The editing efficiency for the target site of FecB gene was 39.13%, whereas the editing efficiency for the target sites (G260, G721 and G1184) of GDF9 gene were 10.52%, 26.67% and 8.00%, respectively. Achieving single base mutation in FecB and GDF9 genes may facilitate improving the reproduction traits of Ouler Tibetan sheep with multifetal lambs.
Animals ; Sheep/genetics* ; Gene Editing ; Tibet ; Mutation ; Phenotype ; Mutagenesis, Site-Directed

Objective:To compare the differences in the prevalence of mild micro-hepatic encephalopathy (MHE) among patients with cirrhosis by using the psychometric hepatic encephalopathy score (PHES) and the Stroop smartphone application (Encephal App) test.Methods:This prospective, multi-center, real-world study was initiated by the National Clinical Medical Research Center for Infectious Diseases and the Portal Hypertension Alliance and registered with International ClinicalTrials.gov (NCT05140837). 354 cases of cirrhosis were enrolled in 19 hospitals across the country. PHES (including digital connection tests A and B, digital symbol tests, trajectory drawing tests, and serial management tests) and the Stroop test were conducted in all of them. PHES was differentiated using standard diagnostic criteria established by the two studies in China and South Korea. The Stroop test was evaluated based on the criteria of the research and development team. The impact of different diagnostic standards or methods on the incidence of MHE in patients with cirrhosis was analyzed. Data between groups were differentiated using the t-test, Mann-Whitney U test, and χ2 test. A kappa test was used to compare the consistency between groups. Results:After PHES, the prevalence of MHE among 354 cases of cirrhosis was 78.53% and 15.25%, respectively, based on Chinese research standards and Korean research normal value standards. However, the prevalence of MHE was 56.78% based on the Stroop test, and the differences in pairwise comparisons among the three groups were statistically significant (kappa = -0.064, P < 0.001). Stratified analysis revealed that the MHE prevalence in three groups of patients with Child-Pugh classes A, B, and C was 74.14%, 83.33%, and 88.24%, respectively, according to the normal value standards of Chinese researchers, while the MHE prevalence rates in three groups of patients with Child-Pugh classes A, B, and C were 8.29%, 23.53%, and 38.24%, respectively, according to the normal value standards of Korean researchers. Furthermore, the prevalence rates of MHE in the three groups of patients with Child-Pugh grades A, B, and C were 52.68%, 58.82%, and 73.53%, respectively, according to the Stroop test standard. However, among the results of each diagnostic standard, the prevalence of MHE showed an increasing trend with an increasing Child-Pugh grade. Further comparison demonstrated that the scores obtained by the number connection test A and the number symbol test were consistent according to the normal value standards of the two studies in China and South Korea ( Z = -0.982, -1.702; P = 0.326, 0.089), while the other three sub-tests had significant differences ( P < 0.001). Conclusion:The prevalence rate of MHE in the cirrhotic population is high, but the prevalence of MHE obtained by using different diagnostic criteria or methods varies greatly. Therefore, in line with the current changes in demographics and disease spectrum, it is necessary to enroll a larger sample size of a healthy population as a control. Moreover, the establishment of more reliable diagnostic scoring criteria will serve as a basis for obtaining accurate MHE incidence and formulating diagnosis and treatment strategies in cirrhotic populations.

Objective:To ascertain the distribution of interventional radiodiagnosis and treatment resources and the current situation of radiological protection in Beijing, standardize the interventional radiodiagnosis and treatment, and promote the implementation of radiation protection regulatory measures.Methods:Various medical institutions at differetn levels that perform interventional radiodiagnosis and treatment in Beijing were identified as the survey objects. With special questionnaires designed, the investigation groups at two levels of municipality and district was established to investigate the basic situation of interventional radiology and occupational health monitoring by the end of 2020. The indexes and parameters were analyzed and evaluated under the relevant national regulations and standards.Results:By the end of 2020, there were 93 medical institutions performing interventional radiology in Beijing, together with 236 digital subtraction angiography machines (DSA) with higher than 800 mA. A total of 135 593 cases of interventional radiological surgical operation were performed. There were 40 hospitals annually performing more than 1 000 cases and 41 hospitals perfoming 10-1 000 cases. There were 3 539 interventional radiological workers, with 99.0% holding radiological worker certificates. The passing rates of occupational health examination, personal dose monitoring and radiation protection training were 96.9%, 99.5% and 95.8%, respectively. A total of 3 532 sets of protective articles were provided for the workers, of which 98.9% were equipped with split or integrated lead clothing, but 6.5% were not equipped with lead protective glasses and 54.9% were not equipped with lead protective gloves.Conclusions:The radiation protection management for the interventional radiodiagnosis and treatment is generally good. However, the regulatory mechanism should be further improved based on the current distribution of interventional radiodiagnosis and treatment resources, with focus on strengthening the occupational health examination, the radiation protection training, and the configuration and use of protective equipment.

Objective:To monitor and analyze the activity concentrations of 7Be and 210Pb in atmospheric aerosol in Beijing from 2017 to 2020. Methods:Totally 1 074 atmospheric aerosol samples were collected by high flow air sampler (SnowWhite) including 275 in spring, 266 in summer, 262 in autumn and 271 in winter and subjected to analysis by low background high-purity germanium gamma-ray spectrometery (ORTEC) to determine the activity concentrations of 7Be and 210Pb. Results:The activity concentrations of 7Be in atmospheric aerosol were from 0.56 to 14.84 mBq/m 3, with an avearage of 6.84 mBq/m 3, and from 0.01 to 9.37 mBq/m 3 for 210Pb, with an avearage 3.19 mBq/m 3. The differences in activity concentrations of 7Be and 210Pb in atmospheric aerosol among differernt seasons were statistically significant ( F=32.66, 93.93, P<0.05). Activity concentration of 7Be was highest in spring, followed by autumn, and lowest in summer and winter. Activity concentration of 210Pb ranged from winter, autumn, spring to summer in descending order. Conclusions:The activity concentrations of 7Be and 210Pb in atmospheric aerosol in Beijing from 2017 to 2020 fluctated within the range of normal level.

Objective To understand the status of new coronavirus contamination in the biosafety laboratory environment, identify key areas prone to contamination, and provide evidence for disinfection of central objects. Methods surfaces of high-frequency contact environment and protective equipment were sampled with moistened sterile cotton swabs after experiment and before disinfection, the results of the one-step real-time reverse transcription polymerase chain reaction (RT-PCR) of open reading frame 1ab and N fragment were used to evaluate the pollution status. Results Environmental surveys found 4 of 217 samples of environmental objects to be positive for new coronavirus RNA, that positive rate was 1.84%. Among them, BSL-3, BSL-2, and BSL-1 were sampled 23, 184, and 10 respectively. The 3 positive samples were from surfaces of nucleic acid extraction room of BSL-2 and from the handles of pass-through box, laboratory door handles and the outer surface of the alcohol watering pot respectively. The 1 positive sample was from the forearm of the protective clothing in BSL-2 laboratory. Conclusion There was a certain degree of virus pollution in key areas of the new coronavirus laboratory. The BSL-2 laboratory has a higher risk of environmental pollution than the BSL-3 and BSL-1 laboratories.

BACKGROUND: Interstitial lung disease (ILD) is a group of diffuse lung diseases that mainly involve the interstitial and alveolar cavities and result in loss of alveolar-capillary functional units, leading to restrictive ventilatory dysfunction and diffusion impairment. There was an increased incidence of lung cancer on the basis of ILD, and perioperative risk of patients with lung cancer combined with ILD (LC-ILD) was significantly increased. The aim of this study is to summarize the safety and experience of surgical treatment of LC-ILD. METHODS: A retrospective analysis was performed on 23 patients with LC-ILD who underwent pneumonectomy in Beijing Hospital from January 2012 to December 2019, and their clinical manifestations, image feature, pathology, surgical safety, perioperative complications and treatment experience were summarized. RESULTS: A total of 23 patients were included in this study, including 20 males (87.0%) with an average age of (69.1±7.8) years, and 19 cases (82.6%) were smokers. Of the ILD types, 14 cases (60.9%) were idiopathic pulmonary fibrosis, 7 cases (30.4%) were idiopathic nonspecific interstitial pneumonia, and 2 (8.7%) were interstitial lung disease associated with connective tissue diseases. The pathology of lung cancer included adenocarcinoma (30.4%, 7/23), small cell carcinoma (30.4%, 7/23), squamous cell carcinoma (26.1%, 6/23), small cell carcinoma mixed with squamous cell carcinoma (4.3%, 1/23) and large cell neuroendocrine carcinoma (8.7%, 2/23). Surgical approaches included video assisted thoracoscopy (69.6%, 16/23) and anterolateral thoracotomy (30.4%, 7/23), with lobectomy (52.2%, 12/23), double lobectomy (4.3%, 1/23), and sublobectomy (39.1%, 9/23). There were 11 cases (47.8%) of postoperative complications, including 8 cases (34.8%) of pulmonary complications, 4 cases (17.4%) of acute exacerbation of ILD (AE-ILD), 6 cases (26.1%) of atrial fibrillation, and 1 case (4.3%) of acute left ventricular dysfunction. The 90-day mortality is 8.7% (2/23) and the cause of death was acute exacerbation of ILD. CONCLUSIONS Most of LC-ILD were elderly patients with multiple comorbidities and decreased pulmonary function, leading to significantly increased surgical risk. The ILD should be fully evaluated and controlled before surgery, intraoperative trauma should be minimized, and special attention should be paid to pulmonary complications and AE-ILD after surgery. Postoperative AE-ILD has a poor prognosis and glucocorticoids may be effective. Early diagnosis and treatment is the key to treatment of AE-ILD.

Objective To investigate the impact of pooling of inactivated samples on testing results of nucleic acid detection of SARS-CoV-2, and to provide a scientific detection scheme for the SARS-CoV-2 nucleic acid screening of large population samples. Methods The SARS-CoV-2 positive throat swab samples and the negative throat swab samples were inactivated at 56°C for 30 minutes, and mixed according to the ratio of positive samples to negative samples at 1:4, 1:9, and 1:19, respectively. Real-time fluorescent RT-PCR technology was used to detect the ORF-lab and N genes in the original solution and mixed solution. Results The nucleic acid test results of the 20 groups of inactivated samples were all positive. The nucleic acid test results of the 1:5 mixture and the 1:10 mixture were also positive. One group of samples of the 1:20 mixture was negative for ORF-lab and positive for the N gene. The Ct values of nucleic acid detection among all groups were significantly correlated. There was no statistically significant difference in the positive rate between different sample groups. Compared with the original solution, the Ct values of the ORF-lab gene of 1:5 mixture, 1:10 mixture, and 1:20 mixture samples increased by 1.73, 2.86, and 4.05, respectively, while the Ct values of the N gene of 1:5 mixture, 1:10 mixture and 1:20 mixture samples increased by 1.69, 2.79, and 3.25, respectively. Conclusion When conducting nucleic acid screening for SARS-CoV-2 in large population samples, a mixed test of less than 10 inactivated samples would not affect the qualitative results in most cases, but the results of weak positive samples may be affected.

BACKGROUND: DNA polymerase β is one of the key enzymes for DNA repair and it was reported that about 30 percent of different types of cancers carried mutations in its coding gene Polb. However, it is still controversial whether it is true or false because of the small sample size in these studies. In current study, we performed genetic screening of promoter and coding regions of Polb gene in 69 Chinese lung cancer patients using Sanger sequencing method, so as to elucidate real mutation frequency of Polb mutations in Chinese Han population. METHODS: Salting out extraction method was used to get the genome DNAs from tumor and normal matched tissues of 69 lung cancer patients. The promoter and 14 coding regions of Polb gene were then amplified using these DNAs as the template. After purification, amplicons were sequenced and aligned to the wild type Polb gene in NCBI database, in order to find out the mutated sites of Polb gene in Chinese lung cancer patients. RESULTS: In this study, we totally found only 5 mutated sites in Polb gene. In detail, 3 mutations (-196G>T, -188_-187insCGCCC, -168C>A) were located in the promoter region; 2 mutations (587C>G, 612A>T) were found in coding regions. Specially, mutations of -188_-187insCGCCC and 587C>G (resulting to the amino acid substitution of Thr to Ser at position 196) had never been reported by other groups before. However, all these 5 mutated sites could be detected in both tumor and matched normal tissues, which inferred that they are not lung tumor specific mutations. CONCLUSIONS No lung tumor specific mutations of Polb gene could be found in Chinese lung cancer patients and Polb gene mutation might not be a molecular marker for Chinese lung cancer patients.

Objective To analyze the performance differences of CT scanners with different detector rows between different manufacturers,and to provide the basis for the rational allocation and use of these CT scanners.Methods According to the result from the sentinel surveillance in 2014,a total of 148 medical institutions were equipped with CT scanners in 16 districts of Beijing,including general hospital(53),cancer hospital(5),TCM hospitals(25),children′s hospitals(2),community hospitals(30)and other specialized medical institutions(33).According to the principle of simple random sampling,40 medical institutions are selected,including 14 general hospitals,1 cancer hospital,7 Chinese medicine hospitals,1 children′s hospital,8 community hospitals and 9 other specialized medical institutions.A total of 141 CT scanners are selected from all CT sets of the selected medical institutions from 2012 to 2014.According to GB 17589-2011 X-ray computed tomography device quality assurance testing status test,four parameters related closely to image quality were tested,including CT value(water),noise,high contrast resolution,and low contrast detectability.Results No significant differences were found in CT value(water),noise and low contrast detectability among CT scanners produced by different manufacturers(P＞0.05),whereas high contrast resolution was found to have a remarkable difference(χ2＝34.706,P＜0.05).Significant differences were found in noise,high contrast resolution and low resolution detectability between the CT scanners with ＜64 detector rows and ≥64 detector rows(χ2＝6.978,10.040,15.973,P＜0.05).However,there is no difference in CT value(water)(P＞0.05).For less-than-64 detector row CT scanners,no significant difference was found in CT value(water),noise and low contrast detectability among different manufacturers(P＞0.05).only high contrast resolution differed remarkably(χ2＝9.941,P＜0.05).For more-than-or equal-to-64 detector row CT scanners,CT value(water)and noise have no differences among different manufacturers(P ＞0.05),whereas,there were significant difference in high contrast resolution and low contrast detectability(χ2＝31.376,32.967,P＜0.05).Conclusions There were a few differences in the performance testing of CT scanners from different manufacturers,and the less-than-64 detector row CT scanners have advantages in noise and low contrast detectability compared with the more-than-64 detector row CT scanners,whereas the latter have advantages in high contrast resolution and scanning time,allowing its wider application in medical institutions with more special diseases.