[Screening and management of asymptomatic infection of 2019-novel coronavirus].

At present, the prevention and control of COVID-19 in China has entered a critical period. Recently, various areas outside Hubei Province have gradually begun to resume work and production, but the development of the epidemic situation is still uncertain and complex. A few days ago, researchers gradually began to pay attention to asymptomatic infection of 2019-novel coronavirus and described the disease process of asymptomatic infection and the possibility of being a source of infection. This provided a scientific basis for further optimizing and improving epidemic prevention and control measures. Paying attention to the screening and self-protection of high-risk groups and strengthening the level of detection should be helpful to the detection and management of asymptomatic infection.

[Effects of estradiol on the day of human chorionic gonadotropin administration on adverse perinatal outcomes].

Objective: To investigate the association between estradiol on the day of human chorionic gonadotropin (HCG) administration and birth outcomes among singleton live births following fresh embryo transfers. Methods: Based on the clinical reproduction medicine management system of the First Affiliated Hospital of Nanjing Medical University, this retrospective cohort study collected data of fresh embryo transfer cycles during January 2013 and December 2016, including pregnant women's age, body mass index (BMI), type and cause of infertility, assisted reproductive therapy indicators (fertilization mode, ovulation stimulation protocol, estradiol levels on HCG administration day), adverse birth outcomes[small for gestational age (SGA), premature and low birth weight (LBW)], etc.. A total of 2 060 women with singleton pregnancy (2 061 fresh embryo transfer cycles) were enrolled. Multivariate logistic regression was used to analyze the association between estradiol on HCG administration day and singletons' adverse birth outcomes. Results: The age and BMI of the 2 060 pregnant women were (29.63±3.92) years old and (22.29±2.86) kg/m2. Incidences of SGA, premature and LBW were 9.8% (201/2 061), 6.9% (143/2 061) and 3.5% (73/2 061), respectively. After adjusting for confounders, the risk of LBW in 4 000-4 499 pg/ml group was significantly elevated when compared to estradiol<1 500 pg/ml group [OR (95%CI): 4.42 (1.13-17.24)]. A protective effect of premature was observed in estradiol≥4 500 pg/ml group [OR (95%CI): 0.50 (0.25-0.97)]. Conclusion: The high level of estradiol on HCG administration day might be a risk factor for LBW, but a protective factor for premature.

[Thoughts on the reform of preventive medicine education in the context of new medicine].

Talent training is the core and foundation of public health system construction. Shortage of talents in the field of disease prevention and public health exposed by COVID-19 pandemic highlights the importance of developing preventive medical education. This article analyzes the challenges of medical education in the dilemma of "separation of medical treatment and prevention", and the new requirements for preventive medical education in the construction of New Medicine under the Healthy China strategy. Four aspects including stepping up the resource allocation and investment, educating responsible public health professionals, the education of all medical students who implement the core competence of public health, and the establishment of a continuing education system for preventive medicine have been considered. A series of specific suggestions are put forward including the establishment of a full-chain closed-loop research system to support the cultivation of top-notch innovative public health talents, strengthening the assessment of core public health capabilities for clinical medical professional admission, formulating a "medical and preventive integration" training program for primary health personnel, and implementing "combination of peace and war" public health personnel reserve system, with the purpose of providing reference for the reform and development of preventive medical education in China.

Serum hepatitis B surface antigen correlates with fibrosis and necroinflammation: A multicentre perspective in China.

The kinetics of serum hepatitis B surface antigen (HBsAg) during the natural history of hepatitis B virus (HBV) infection has been studied, but the factors affecting them remain unclear. We aimed to investigate the factors affecting HBsAg titres, using data from multicentre, large-sized clinical trials in China. The baseline data of 1795 patients in 3 multicentre trials were studied, and the patients were classified into 3 groups: hepatitis B early antigen (HBeAg)-positive chronic HBV infection (n = 588), HBeAg-positive chronic hepatitis B (n = 596), and HBeAg-negative chronic hepatitis B (n = 611). HBsAg titres in the different phases were compared, and multiple linear progression analyses were performed to investigate the implicated factors. HBsAg titres varied significantly in different phases (P = .000), with the highest (4.60 log10 IU/mL [10%-90% confidence interval: 3.52 log10 IU/mL-4.99 log10 IU/mL]) in patients with HBeAg-positive chronic HBV infection. In all phases, age and HBV DNA were correlated with serum HBsAg level. In HBeAg-positive chronic hepatitis B patients, a negative correlation between HBsAg titres and fibrosis stage was observed. Alanine amonitransferase or necroinflammatory activity was also correlated with HBsAg titres in HBeAg-negative chronic hepatitis B patients. In conclusion, decreased HBsAg titres may be associated with advancing fibrosis in HBeAg-positive chronic hepatitis B patients or increased necroinflammation in those with HBeAg-negative chronic hepatitis B. Our findings may help clinicians better understand the kinetics of HBsAg and provide useful insights into the management of this disease.

[Analysis on factors related to spontaneous reduction in twin pregnancy following assisted reproductive technology].

Objective: To explorer factors related to spontaneous reduction in twin pregnancy following assisted reproductive technology. Methods: 2 848 twin pregnant women with treatment of vitro fertilization-embryo transfer (IVF-ET) or intra cytoplasmic sperm injection (ICSI) cycles were enrolled at Assisted Reproductive Centre of the First Affiliated Hospital of Nanjing Medical University, Nanjing Maternity Hospital and Shengjing Hospital of China Medical University from January 2013 to December 2016 respectively. Basic features of subjects, relevant clinical indicators, factors of assisted reproductive therapy and pregnancy outcome were collected from clinical assisted reproductive technology management system. According to the pregnancy outcome, the subjects with spontaneous reduction were classified as case group (n=686), and those with normal twin birth were classified as control group (n=2 162). The features of subjects in the two groups were compared. Non-conditional logistics regression model was used to analyze the related factors of the occurrence of spontaneous reduction. Results: The age of case group and control group were (30.6±4.3) and (30.2±4.0) years old respectively. After the adjustment of male sterile factor, compared to the subjects with luteinizing hormone level on the day of human chorionic gonadotropin administration (HCG) <1.43 IU/L, OR (95%CI) of the subjects with value at 2.59-5.10 IU/L was1.62 (1.08-2.42).Compared to the subjects with number of transferred embryo as 1, OR (95%CI) of the subjects with value as 3 was 0.23 (0.07-0.74). Compared to the subjects with stage of transferred embryo as cleavage stage, OR (95%CI) of the subjects with blastula stage was 0.42 (0.27-0.67). Conclusion: Luteinizing hormone level on day of HCG, number and stage of embryo transfer are related factors to spontaneous reduction in twin pregnancy following assisted reproductive technology.

[Data management and quality control strategies for population based cohort study].

Large-scale cohort study has unique advantages in the field of etiology research for its large sample size a multi-time point data, but it also brings great difficulty in data management and quality control at the same time. Recently, China has initiated a number of large-scale population cohort studies, posing enormous challenges to the management and quality control of related cohort data. This paper summarizes the existing experience and consensus in the field of cohort study in China from the characteristics of the cohort data, aiming at the types and main forms of the four main sources of questionnaire data, clinical diagnosis and treatment data, biological sample detection data and observation outcome data, from the data storage, circulation and transmission work.The contents and methods of queue data management are comprehensively summarized. Corresponding data quality control strategies are advised in the questionnaire evaluation, data logic verification, survey object sampling and multi-database review, etc. The goal of this review is to provide guidance for the management of data and the formulation of quality control strategies in the cohort study in China.

[Clinical value of classified detection of circulating tumor cells in peripheral blood of NSCLC patients].

OBJECTIVE: To investigate the clinical value of detection of circulating tumor cells (CTCs) classified by epithelial cell adhesion molecule (EpCAM) in peripheral blood of patients with non-small cell lung cancer (NSCLC). METHODS: Peripheral blood samples (7.5 ml each time) were collected from 47 NSCLC patients. Among them, blood samples were collected at the end of each therapy-cycle in three patients for longitudinal monitoring of CTCs. CTCs were enriched by the depletion of leucocytes using a magnetic bead separation technique, stained with EpCAM, cytokeratin 7/8 and their isotypic control antibodies, respectively, and then identified and counted by multi-parameter flow cytometry. RESULTS: In the blood samples from 47 patients, EpCAM-positive CTCs were detected in 64.3%(9/14), 40.0%(4/10) and 43.5%(10/23) of patients in stages Ⅰ-Ⅱ, Ⅲ and Ⅳ, respectively. EpCAM-negative CTCs were detected in 78.6%(11/14), 90.0%(9/10) and 91.3%(21/23) of patients in stage Ⅰ-Ⅱ, Ⅲ, and Ⅳ, respectively. The total detection rates of EpCAM-positive and EpCAM-negative CTCs were 48.9%(23/47) and 87.2%(41/47), respectively, showing a statistically significant difference between them (P<0.001). According to the stage of the cancer, there was a significant difference between the detection rates of the two types of CTCs in patients of stage Ⅳ(P=0.001), but not in stage Ⅰ-Ⅱ and Ⅲ (P>0.05). The number of EpCAM-negative CTCs was significantly higher than that of EpCAM-positive CTCs in all stages (P<0.05). The frequency of patients with the percentage of EpCAM-negative CTCs >90% was significantly higher in stage Ⅳ patients than that in stage Ⅰ-Ⅱ cases (P=0.030), while the frequency of patients with the percentage of EpCAM-negative CTCs between 50%~90% was significantly lower in the stage Ⅳ than that in the stage Ⅰ-Ⅱ patients (P=0.001). The treatment of most patients with EpCAM-negative CTCs >50% showed to be ineffective (P=0.033). CONCLUSION: Detection of CTCs classified by EpCAM in peripheral blood is helpful in evaluating the distant metastasis and treatment effectiveness of NSCLC patients.

[DNA damage associated genetic variants contribute to lung cancer susceptibility in a Han Chinese population].

OBJECTIVE: To explore the association between DNA damage-related genetic variants and lung cancer susceptibility in a Han Chinese population. METHODS: This case-control study enrolled patients from the Cancer Hospital of Jiangsu Province and Jiangsu Province Hospital from 2003 to 2009. Controls were randomly selected from individuals who visited the same hospital or a community-based health examination program during the same time period. A 5 ml venous blood sample was obtained from each participant and epidemiological information was collected on a standard questionnaire. Illumina Infinium(®) BeadChip was used for genotyping of 35 DNA damage-related single nucleotide variations (SNVs), which were identified in our previous study. Multivariate and binary logistic regressions were used to calculate the OR and 95%CI for lung cancer risk. HaploReg V4.1 and Regulome DB were used to understand functional annotation on important SNV. RESULTS: The distributions of age (61.06±10.15) vs. (61.32±11.07) years; t=-0.72, P=0.473) and sex (χ(2)=1.81, P=0.179) were similar between cases and controls. However, the case group had a higher frequency of smokers (61.08% vs. 48.54%; χ(2)=50.04, P<0.001) and heavy smokers (42.28% vs. 24.07%; χ(2)=122.32, P<0.001). Among the 34 SNVs that passed quality control, two SNVs were significantly associated with lung cancer risk after adjustments for age, sex and cumulative smoking dose: rs9267576 C>A (CA genotype/CC genotype, OR=1.56, 95% CI: 1.01-2.40) and rs3130683 A>G (AG genotype/AA genotype, OR=1.87, 95%CI: 1.13-3.09). After step-wise logistic regression analysis, only the rs3130683 SNV was retained in the model, indicating that the association between rs9267576 and lung cancer may be due to the effect of rs3130683. Functional annotation indicated that rs3130683 was located in the promoter and enhancer regions, and was an expression quantitative trait loci of HLA. The Cancer Genome Atlas indicated that expression of HLA-C, DQB1, DRB1 and DRB5 in lung cancer tissue was significantly lower than in paired normal tumor-adjacent tissue, with down-regulation of the four respective genes in 81.3%, 88.8%, 90.7% and 90.7% of lung cancer tissues (P-values were 6.68×10(-15), 2.21×10(-13), 2.20×10(-16), 2.58×10(-13), respectively). CONCLUSIONS: The SNV rs3130683 (A>G) was associated with the risk of lung cancer in a Han Chinese population. This SNV may affect the risk of lung cancer by regulating HLA expression.

[Association between prenatal exposure to PM2.5 and fetal growth: a prospective cohort study].

Objective: To investigate the association of exposure to PM2.5 and its constituents during pregnancy and fetal growth and to further identify critical windows of exposure for fetal growth. Methods: We included 4 089 mother-child pairs from the Jiangsu Birth Cohort Study between January 2016 and October 2019. Data of general characteristics, clinical information, daily average PM2.5 exposure, and its constituents during pregnancy were collected. Fetal growth parameters, including head circumference (HC), abdominal circumference (AC), and femur length (FL), were measured by ultrasound after 20 weeks of gestation, and then estimated fetal weight (EFW) was calculated. Generalized linear mixed models were adopted to examine the associations of prenatal exposure to PM2.5 and its constituents with fetal growth. Distributed lag nonlinear models were used to identify critical exposure windows for each outcome. Results: A 10 µg/m3 increase in PM2.5 exposure during pregnancy was associated with a decrease of 0.025 (ß=-0.025, 95%CI: -0.048- -0.001) in HC Z-score, 0.026 (ß=-0.026, 95%CI: -0.049- -0.003) in AC Z-score, and 0.028 (ß=-0.028, 95%CI:-0.052--0.004) in EFW Z-score, along with an increased risk of 8.5% (RR=1.085, 95%CI: 1.010-1.165) and 13.5% (RR=1.135, 95%CI: 1.016-1.268) for undergrowth of HC and EFW, respectively. Regarding PM2.5 constituents, prenatal exposure to black carbon, organic matter, nitrate, sulfate (SO42-) and ammonium consistently correlated with decreased HC Z-score. SO42- exposure was also associated with decreased FL Z-scores. In addition, we found that gestational weeks 2-5 were critical windows for HC, weeks 4-13 and 19-40 for AC, weeks 4-13 and 23-37 for FL, and weeks 4-12 and 20-40 for EFW. Conclusions: Our findings demonstrated that exposure to PM2.5 and its constituents during pregnancy could adversely affect fetal growth and the critical windows for different fetal growth parameters are not completely consistent.

Mass oscillations and matter wave's phase and amplitude modulations of relativistic quantum particles induced by Heisenberg's uncertainty principle.

We present a flip-flop dual-component model to treat quantum dynamics of relativistic particles with a rest mass and investigate the matter waves' phase and amplitude modulations due to Heisenberg's uncertainty principle. Their matter waves behave like a traveling Gaussian-shaped wave packet accompanied by a guiding pilot wave, and the phase modulations result in mass oscillations. These effects are more prominent for light-weighted elementary particles, such as neutrinos and electrons. This mechanism is solely due to the uncertainty principle and has nothing to do with the flavor-mixing of neutrinos. Simulations using neutrinos and electrons are presented, which indicate an oscillation period on the order of ps. This study primarily focuses on the predicted mass oscillations induced by the uncertainty principle. A slit-type interference experiment using neutrinos and electrons from reactors is proposed to test the predicted behaviors.

[Mediation effect of smoking and healthy diet score on the association between educational level and the risk of lung cancer incidence].

Objective: To evaluate the possible mediation effect of smoking and healthy diet score on the association between educational level and the risk of lung cancer incidence. Methods: After excluding individuals with missing educational levels and cancer information at baseline, 446 772 participants in the UK Biobank (UKB) prospective cohort study were included. Cox regression models were used to investigate the associations of educational level and smoking and healthy diet score with the incidence of lung cancer. Mediating effect analysis was conducted to analyze the mediating effect of smoking and healthy diet score on the correlation between educational level and lung cancer. Results: During a median follow-up of 7.13 years, 1 994 new- onset lung cancer cases were observed. Per 1 standard deviation (5 years) increase in educational level was associated with a 12% lower risk of lung cancer (HR=0.88, 95%CI: 0.84-0.92). The corresponding level 1-5 in the International Standard Classification for Education (ISCED) were mapped to UKB self-report highest qualification to estimate the educational level. A higher rank means a higher educational level. Compared with level ISCED-1, the HR(95%CI) of level ISCED-2, ISCED-3, ISCED-4 and ISCED-5 were respectively 0.83 (0.72-0.94), 0.67 (0.53-0.85), 0.76 (0.65-0.89) and 0.72 (0.64-0.80) for lung cancer. Education years were negatively correlated with smoking, with ß coefficients (95%CI) being -0.079 (-0.081- -0.077), but positively correlated with healthy diet score (ß=0.042, 95%CI: 0.039-0.045). Analysis of mediating effect indicated that the association of educational level with lung cancer risk was mediated by smoking and healthy diet score, the proportions of mediating effect were 38.952% (95%CI: 31.802%-51.659%) and 1.784% (95%CI: 0.405%-3.713%), respectively. Conclusion: Smoking and healthy diet score might mediate the effect of educational level on the incidence of lung cancer, indicating that improving the level of education can reduce the risk of lung cancer by changing lifestyles such as smoking and diet.

Environmental impacts of the shelter forests in Horqin Sandy land, northeast China.

Assessing environmental effects of shelter forests is primarily necessary for realizing their greatest protective benefits. The Three-North Shelter Forest Program (TNSFP), the largest ecological afforestation program in the world, has been operated for three decades in China but so far lacks comprehensive assessment of its environmental impacts. Horqin Sandy Land (HSL) in Northeast China is one of the key areas in the TNSFP implementation. To identify the principal contributors to environmental changes in HSL, we evaluated impacts of variations in landscape features, shelter forest areas, climatic factors, and social factors on changes in sandy land areas from 1978 to 2007, by using Gray Relational Analysis. Our analysis showed that during the period 1978 to 2007, the sandy land area decreased by 3.9% in low aeolian dunes, 14.5% in low mountains and hills, and 98.9% in high elevation alluvial flats of HSL. Factors with Gray Correlation Degrees >0.9 were identified as the patch shape index (PSI) and the landscape isolation index (LII) of grasses in low aeolian dunes, PSI of grasses in mountains and hills, and area of broadleaved forests and LII of shrubs in alluvial flats. It is concluded that establishment of the shelter forests has played a significant role in controlling the expansion of sandy land in HSL. To sustain the long-term environmental benefits of the shelter forests in the remaining period for TNSFP construction, suitable tree species should be selected and planted at appropriate densities based on the local precipitation, groundwater and landform conditions, and the system stability of the total landscape.

[Epidemiological research in the big data era: opportunities, challenges and prospectives].

Recent years with the rapid progress in high-throughput omics techniques, the accumulation of population cohorts and biobanks, great advances in internet and information technology, and the emerging tools for big data utilization, health care big data provide abundant data resources and broad research platforms for epidemiological research. We aimed to review the opportunities and challenges of epidemiological research in the era of big data, and explore the future development of epidemiology. Epidemiology should seize the opportunities, open up new directions, develop new methods, and promote the translation of research results into public health and clinical medicine, which will eventually realize the vision of "Healthy China".

[Polygenic risk score in personalized screening of lung cancer: a prospective cohort study in Chinese].

Objective: To explore how to personalize lung cancer screening programs for prevention in Chinese populations based on individual genetic risk score. Methods: We constructed the lung cancer polygenic genetic risk score (PRS-19) based on the 19 previously published genetic variations, using 100 615 participants with genotyping data from the China Kadoorie Biobank (CKB). Using the 5-year absolute risk of lung cancer in a population (55 years old with at least 30-pack-year history of smoking) as reference, the trend of 5-year absolute risk in different genetic risk groups was calculated in smokers and non-smokers, respectively. Distribution curves of 5-year absolute risk were also described to determine the theoretical age or smoking dose when different genetic risk groups reached the reference values. Given the overall findings, the specific start age for lung cancer screening were suggested for different genetic risk groups. Results: The 5-year absolute risk of lung cancer was 0.67% in 55-year-old smokers with 30 packs per year in the CKB. Among smokers, 5-year absolute risk of participants increased as the genetic risk increased. Hence, it was recommended that people at high genetic risk should start screening earlier. For the highest genetic risk populations (the top 1% of PRS), the start age might be changed to 50 years old. If the start age remained at 55-year-old, the smoking dose should be set lowered in high genetic risk populations. For the highest genetic risk populations, they should be included in lung cancer screening regardless of the cumulative smoking exposure. Among nonsmokers, it was also valuable to screen people with high genetic risk, considering the start age of 62 for the highest genetic risk populations and 74 for the lowest genetic risk populations (the bottom 5% of PRS). Conclusions: PRS-19 can be effectively used in developing lung cancer screening program for individualized prevention in China. For smokers with high genetic risk, the recommended starting age and smoking dose could be lowered for lung cancer screening, and non-smokers with high genetic risk could also be included in the screening programs.

[Quality control and measures of China National Birth Cohort].

Birth cohort is an effective method to explore the relationship between various prepregnant and pregnant exposures and the health of fetuses, infants and young children. It is a long construction period to build a birth cohort and the quality of research may be affected by many factors. This paper reviews the quality assurance and quality control measures in the process of China National Birth Cohort (CNBC), and summarizes the construction experience. We aim to provide experience for related cohort studies, which could improve the quality of cohort studies through removing the impact of related factors. CNBC adopted a series of measures to ensure the quality of research in the top-level design of quality assurance, including screening research center, developing member management system, formulating standard operating procedures and training staff by it. In terms of quality control, it includes real-time, timely and timing quality control for the process of data generation, full-cycle quality control for biological sample collection, processing, storage and comprehensive three-dimensional quality control for staff training, supervision and quantitative assessment.