As a limiting factor in telomerase activity,telomerase reverse transcriptase(TERT)controls cellular senescence and apoptosis by maintaining telomere length.TERT is not expressed or little expressed in most normal cells.However,the abnormal overexpression of TERT promotes the ability of tumor cells to replicate indefinitely.This review summarizes the regulatory mechanisms of TERT expression,including the main transcription factor families,single nucleotide polymorphism sites,and epigenetic modification changes such as DNA methylation,histone modification,and non-coding RNA.The role of these molecular mechanisms as well as significant TERT single-base variants and virus integration variants in the occurrence and development of cancer are reviewed.On this basis,its application in tumor diagnosis and prognosis is discussed.

Objective To explore the comparative application of phase and diaphragmatic navigation in three-dimensional magnetic resonance cholangiopancreatography(3D-MRCP)thin-layer scanning in elderly patients.Methods A total of 180 elderly patients were scanned by phase and diaphragmatic navigation via Siemens Aera1.5T superconducting MR scanner.The acquired images were reconstructed by 3D reconstruction.The anatomical structure,image quality and disease diagnosis were compared between the phase and diaphragmatic navigation groups.Results In liver of anatomy,the liver of primary bile duct,the superior,middle and inferior extrahepatic bile duct and the gallbladder could be well displayed,and the difference was not statistically significant between the two groups(P＞0.05).The display of pancreatic duct and the liver of secondary bile duct of diaphragmatic navigation was significantly better than those of phase navigation(P＜0.05).In terms of image quality,the excellent rate of diaphragmatic navigation was significantly higher than that of phase navigation,and the difference was statistically significant(P＜0.05).There were no statistically significant differences in the detection rate of pancreatobiliary system diseases,the diagnostic rate of cholelithiasis,common bile duct stones,common bile duct dilatation and pancreatic duct dilatation between the two groups(P＞0.05).Conclusion Diaphragmatic navigation is signifi-cantly better than phase navigation in the display of the anatomical structure of the pancreatic duct,the liver of secondary bile duct,and the excellent rate of image quality.Diaphragmatic navigation is more suitable for thin-layer 3D-MRCP scanning in elderly patients.

Upper respiratory tract is directly connected with the external environment， and its natural immune system is the first line of defense against pathogens. In antiviral infection， interferon （IFN） is the main component of the antiviral natural immune system and IFN-λ is a newly discovered immune effector molecule that is mainly produced in the mucosal barrier. IFN-λ exerts a biological role through Janus kinase （JAK） and signal transducer and activator of transcription （STAT） signaling pathway， and plays an important part in regulating innate and acquired immunity of respiratory mucosa. IFN-λ principally expresses on the mucosal barrier with a long-lasting antiviral impact and controls immune-inflammatory damage， which is becoming a new focus of antiviral immunity research in the upper respiratory tract， especially in fighting against 2019 novel coronavirus diseases （COVID-19）. Thus， we summarize the research progress of IFN-λ antiviral immunity in the upper respiratory tract to provide new insight in the prevention and treatment of viral infection in the upper respiratory tract.

ObjectiveTo investigate the related factors of hypertension and comorbid hypertension-diabetes mellitus （HT-DM） among rural residents in Shanghai， China. MethodsA total of 2 159 residents over 35 years old were randomly selected from a rural community in the suburbs of Shanghai through cluster random sampling. Their basic sociological characteristics and blood lipid levels were investigated. Chi-square test was used to analyze the relationship between hypertension （or HT-DM） and gender， age， education levels， marital status， original household registration and current household registration. The relationship between hypertension （or HT-DM） and blood lipid level was analyzed by a conditional logistic regression model. ResultsThe prevalence of hypertension was 26.35% and that of HT-DM was 4.68% in the study population. Chi-square test analysis showed that hypertension was significantly associated with age， marital status， educational level， and rural household registration， while HT-DM was significantly associated with age， educational level， and rural household registration. Chi-square trend analysis indicated that the prevalence of hypertension and HT-DM increased with age in both male and female populations （χ²=129.82， 193.04，both P<0.001， and χ²=9.29， 40.57， both P<0.01）. The unconditional logistic regression analysis indicated that the lower level of high-density lipoprotein cholesterol （HDL-C） and higher level of triglyceride （TG） were associated with an increased the risk of hypertension by 2.79 times and 2.06 times， respectively. The lower level of HDL-C increased risk of HT-DM by 4.21 times. ConclusionThe prevalence of hypertension in the rural population in Shanghai is relatively high. Age， education level， rural household registration and HDL-C are common related factors of hypertension and HT-DM.

OBJECTIVE： To establish a method for simultaneous determination of spinosin and jujuboside A in the seads of Ziziphus jujuba， and to investigate its quality grading standard. METHODS： HPLC-ELSD method was adopted. The separation was carried out on Inertsil ODS-SP column with mobile phase consisted of acetonitrile-water （gradient elution） at the flow rate of 1.0 mL/min. The column temperature was 30 ℃， the temperature of drift tube was 90 ℃， the flow of carrier gas was 2.9 L/min and injection volume was 20 μL. The thickness， width， length and 100-grain quality of the medicinal materials were used as indicators to investigate the appearance traits. SPSS 22.0 software was used to analyze the correlation of the contents of spinosin and jujuboside A， its appearance traits with the quality constant of TCM， and establish a quality classification standard for the seads of Z. jujuba. RESULTS： The linear range of spinosin and jujuboside A were 1.03-6.18 μg/mL （r＝0.999 7）， 1.05-6.30 μg/mL （r＝0.999 8）； the limits of quantitation were 0.171， 0.174 μg/mL， respectively； the limits of detection were 0.052， 0.053 μg/mL， respectively. RSDs of precision， stability and reproducibility tests were all lower 2％. The recoveries were 99.01％-102.97％ （RSD＝1.39％， n＝6）， 97.94％-101.03％ （RSD＝1.13％， n＝6）， respectively. Correlation analysis results showed that the length， width， 100-grain quality spinosin content and jujuboside A content of the medicinal materials were positively correlated with the quality constant of TCM. The results of quality classification for 30 batches of medicinal materials showed that S1-S4 and S7-S12 were first-class products； S5， S6， S13-S17 and S20-S30 were second-class products； S18 and S19 were third-class products. CONCLUSIONS： Established content determination method is simple， precision， accurate and stable， and can be used for simultaneous determination of spinosin and jujuboside A in the seads of Z. jujuba. Established quality grading standard of the seads of Z. jujuba can be used to evaluate the quality.

Objective: Network pharmacology combines drug and disease targets with biological information networks based on the integrity and systematicness of the interactions between drugs and disease targets. This study aims to explore the molecular basis of Hanshi Zufei formula for treatment of COVID-19 based on network pharmacology and molecular docking techniques. Methods: Using TCMSP, the chemical constituents and molecular targets of Atractylodis Rhizoma, Citri Reticulatae Pericarpium, Magnoliae Officinalis Cortex, Pogostemonis Herba, Tsaoko Fructus, Ephedrae Herba, Notopterygii Rhizoma et Radix, Zingiberis Rhizoma Recens, and Arecae Semen were investigated. The predicted targets of novel coronavirus were screened using the NCBI and GeneCards databases. To further screen the drug-disease core targets network, the corresponding target proteins were queried using multiple databases (Biogrid, DIP, and HPRD), a protein interaction network graph was constructed, and the network topology was analyzed. The molecular docking studies were also performed between the network's top 15 compounds and the coronavirus (SARS-CoV-2) 3CL hydrolytic enzyme and angiotensin conversion enzyme II (ACE2). Results: The herb-active ingredient-target network contained nine drugs, 86 compounds, and 49 drug-disease targets. Gene ontology (GO) enrichment analysis resulted in 1566 GO items (P < 0.05), among which 1438 were biological process items, 35 were cell composition items, and 93 were molecular function items. Fourteen signal pathways were obtained by enrichment screening of the KEGG pathway database (P < 0.05). The molecular docking results showed that the affinity of the core active compounds with the SARS-CoV-2 3CL hydrolase was better than for the other compounds. Conclusion: Several core compounds can regulate multiple signaling pathways by binding with 3CL hydrolase and ACE2, which might contribute to the treatment of COVID-19.

Malignant tumors can be classified into three categories， rapidly progressing tumors， slowly progressing tumors， and "indolent" tumors. Rapidly progressing tumors （such as liver cancer， pancreatic cancer， and cholangiocarcinoma） have acute onset， shorter time duration from onset to death， and poorer treatment effects， which warrants primary prevention. Slowly progressing tumors （such as lung cancer， colorectal cancer， breast cancer， and gastric cancer） have slow onset， clear precancerous lesions， longer time duration from onset to death， and better therapeutic effects， which is accordingly suitable for secondary prevention. “Indolent” tumors （such as prostate and thyroid cancer） do not affect the life expectancy and are suitable for tertiary prevention. Early screening of “indolent” tumors may lead to overtreatment. Furthermore， early screening of rapidly progressing tumors is difficult to identify early cancers， which results in low cost-effectiveness. In contrast， for slowly progressing tumors suitable for secondary prevention， early screening may have cost-effectiveness， though there might be over-diagnosis. It is crucial to adopt appropriate prevention and treatment strategies for diverse types of tumors. Currently， large-scale cohort studies and randomized controlled clinical trials with complete follow-up may accurately evaluate the effect of cancer prevention strategies. This review discusses the significance of screening in precision prevention of tumors based on the characteristics of tumor progression and patients’ prognosis.