Objective To investigate the correlation of previous hepatitis B virus (HBV) infection with the incidence risk of chronic pancreatitis (CP).Methods This was a case control study.Five hundred and seventy-one patients with CP admitted in the Department of Gastroenterology, Changhai Hospital, Second Military Medical University between January 2015 and October 2016 were enrolled, and 1216 sex and age matched health individuals were also enrolled as the control group.The 5 serum HBV markers(HBsAg,HBsAb, HBeAg, HBeAb and HBcAb) were detected and their correlation with CP incidence was analyzed.Results The positive rate of HBsAg in the CP group and the control group were 3.0% and 3.8%, respectively, and the difference was statistical significant.(OR=0.039, 95% CI 0.02~0.80, P<0.00), but in all the HBsAg positive models (HBVM) the difference of CP and control groups was not statistical significant.HBsAb positive rate in CP group and the control group were 51.8% and 75.0%, respectively, and the difference was statistical significant(P<0.000).HBeAg positive rate in CP group and the control group were 1.1% and 0.1%, the difference was statistical significant (P<0.05), but in all the HBeAg positive models, the CP group and the control group had no statistical difference (P>0.05).The positive rate of HBeAb in the CP group and the control group were 24.3% and 10.8%, respectively, and the difference was statistical significant(P<0.00).The positive rate of HBcAb in the CP group and the control group were 50.1% and 16.5%, respectively,and the difference was statistical significant(P<0.000).In the(HBsAb+, HBeAb+, HBcAb+), (HBsAb+, HBcAb+), (HBeAb+, HBcAb+), (HBcAb+) models, the positive rate in CP group was significantly higher than that of the control group(P<0.000).Multivariate regression analysis showed that the positivity of HBsAb and HBeAb were the protection factors for the occurrence of CP(P<0.05),and HBcAb positivity was the independent risk factor for CP (OR=6.931,P<0.000).Conclusions HBsAb and HBeAb poitivity were the protectors for CP, while HBcAb positivity could be considered as an independent risk factor for CP.

Objective : To observe the clearance of smear layer on the root canal wall in different action time by scanning electron microscope (SEM), and to determine the optimal amount of time using sonically activated irrigation to wash root canal in clinic. Methods: Fifty-six ex vivo human anterior teeth with single straight root canal were selected. After routine mechanical preparation, they were divided into two experimental groups according to different irrigating agents: saline group and EDTA group. Each group was assisted by VDW sonic activation EDDY. The saline group was divided into three subgroups according to the irrigating time: 5 s, 30 s and 50 s; EDTA group was divided into six subgroups according to the irrigating time: 5 s, 10 s, 20 s, 30 s, 40 s and 50 s. The control group did not undergo root canal irrigation. After irrigation, the root was cut longitudinally. The smear layer of crown, middle and apical of root canal wall was observed by SEM. Results: After irrigating for 30 seconds, there was a significant difference between the normal saline group and the control group and the 5 second group (P<0.05), and there was no difference in the middle and apical part (P>0.05). After 50 seconds, there was a significant difference in the score of the smear layer between the apical area and the other groups (P<0.05). After irrigating for 5 seconds or 10 seconds in EDTA group, there was a significant difference between the scores of the crown and middle area of the root canal and the control group (P<0.05), and there was no significant difference in the apical area (P>0.05). There was a significant difference between the 20-40 second group and the first two groups (P<0.05). There was a significant difference between the 50 second group and the other groups (P<0.05). Comparing the cleaning effect on the smear layer after 50 seconds of irrigating between the two experimental groups, the whole root canal showed significant statistical difference (P<0.05). Conclusion The EDTA-assisted sonic activated device used for 50 seconds has the best cleaning effect.

Objective:To systematically review the progress, advantages, disadvantages, precautions and future trends of virtual simulation technology used in epidemiology teaching.Methods:A systematical literature retrieval was conducted by using PubMed, Web of Science, Embase, China National Knowledge Infrastructure, Wanfang Data and VIP Paper Check System with key words of epidemiology, teaching and virtual simulation, and the literatures included were screened and classified with narrative integration method. Chinese virtual simulation teaching platforms were used to select the literatures about existing epidemiology virtual simulation teaching projects for integration and analysis.Results:A total of 22 articles were included (7 in Chinese and 15 in English), most of which were teaching projects for students majoring in Public Health. We also found 24 national first-class courses and 21 provincial first-class courses in virtual simulation of epidemiology in China. The application of virtual simulation technology in epidemiology education is still in its infancy, and the interaction degree is mostly moderate. It is mainly used in three scenarios: improving the visualization degree of complex concepts and structures, training the operational skills through low-risk and low-cost virtual environment, serving as an effective supplement to the teaching of epidemiological field investigation and response to public health emergencies. In terms of effect, it is conducive to students' understanding of epidemiology related phenomena and principles, and has the advantages of breaking through time and space constraints, reducing teaching costs and risks, improving students' attention and satisfaction and so on. However, it also faces the lack of foundation in the initial stage, and some students have problems such as psychological and physiological discomfort. In the future, we need to optimize the development process, program design and so on. At the same time, we should conduct more in-depth research on cost calculation, effect evaluation and curriculum integration.Conclusions:The application of virtual simulation technology in epidemiology education is an important part of training high-level applied public health talents. We encourage to actively carry out virtual simulation teaching in epidemiology, and train public health talents with Chinese characteristics.

BACKGROUND: Vaccination has been shown effective in controlling the global coronavirus disease 2019 (COVID-19) pandemic and reducing severe cases. This study was to assess the flare and change in disease activity after COVID-19 vaccination in patients with stable rheumatoid arthritis (RA). METHODS: A prospective cohort of RA patients in remission or with low disease activity was divided into a vaccination group and a non-vaccination group based on their COVID-19 vaccination status. Each of them was examined every 3 to 6 months. In the vaccination group, disease activity was compared before and after vaccination. The rates of flare defined as disease activity scores based on 28-joint count (DAS28) >3.2 with ΔDAS28 ≥0.6 were compared between vaccination and non-vaccination groups. RESULTS: A total of 202 eligible RA patients were enrolled. Of these, 98 patients received no vaccine shot (non-vaccination group), and 104 patients received two doses of vaccine (vaccination group). The median time interval from pre-vaccination visit to the first immunization and from the second dose of vaccine to post-vaccination visit was 67 days and 83 days, respectively. The disease activity scores at pre-vaccination and post-vaccination visits in the vaccination group patients were similar. At enrollment, gender, RA disease course, seropositivity, and disease activity were comparable across the two groups. Flare was observed in five (4.8%) of the vaccination group patients and nine (9.2%) of the non-vaccination group patients at post-vaccination assessment ( P  = 0.221). In terms of safety, 29 (27.9%) patients experienced adverse events (AEs) after vaccination. No serious AEs occurred. CONCLUSIONS COVID-19 vaccinations had no significant effect on disease activity or risk of flare in RA patients in remission or with low disease activity. Patients with stable RA should be encouraged to receive the COVID-19 vaccination.
Humans ; Arthritis, Rheumatoid ; Cohort Studies ; COVID-19/prevention & control* ; COVID-19 Vaccines/adverse effects* ; East Asian People ; Prospective Studies ; Vaccination/adverse effects*

Objective:To evaluate the association of maternal nutrition status in the first trimester with gestational diabetes mellitus (GDM) and macrosomia.Methods:378 pregnant women who took prenatal care in Shunyi Women′s and Children′s Hospital of Beijing Children′s Hospital were enrolled in the study. Blood samples were collected at first prenatal visit (<12 gestation weeks) to measure the level of hemoglobin and iron status indexes including serum iron, ferritin, transferrin, total iron binding capacity, iron saturation, transferrin saturation. The incidence of GDM and macrosomia were collected and Logistic regression was used to evaluate the associations of maternal nutrients status in the first trimester with GDM and macrosomia.Results:The incidence rate of GDM was16.9%,the incidence of anemia and iron deficiency in the first trimester were2.4% and 2.5%, respectively. After adjustment for variables such as maternal age, pre-pregnancy BMI, family history of diabetes, and parity, Logistic regression showed that in the first trimester, iron saturation>50% ( OR=0.238, 95% CI 0.068-0.831), transferrin saturation>50% ( OR=0.08, 95% CI 0.010-0.677) were protective factors of GDM; iron saturation 25%-50% ( OR=0.361, 95% CI 0.143-0.908); transferrin saturation 25%-50% ( OR=0.383, 95% CI 0.165-0.891); ferritin>30 ng/ml ( OR=0.418, 95% CI0.186-0.939) were protective factors of macrosomia. Conclusion:Maternal iron status in the first trimester might be associated with GDM and macrosomia. Thus, maternal iron status assessment in the first trimester is necessary.

Objective:To establish a rapid method for the detection of varicella-zoster virus (VZV) by recombinase-aid amplification (RAA).Methods:The whole genome sequences of VZV were downloaded from the global shared database for comparison and analysis. Specific primers and probe were designed for the four conserved genes respectively and the optimal combination was selected. The optimal reaction system was selected through the concentration gradient of primers and probes, and a fluorescence RAA detection method was established. The sensitivity of the method was evaluated with VZV positive plasmid standard and clinical samples with gradient dilution, the repeatability of the method was evaluated with the lowest detectable limit concentration of positive plasmid standard, and the specificity of other viral nucleic acid method was evaluated. At the same time, this method and quantitative real-time PCR (qPCR) were used to detect clinical samples and the result were compared.Results:The optimal combination of primer pair F2/R2 and probe P2 targeting open reading frame (ORF) 28 gene was selected. Considering the cost factor, the optimal primer concentration was set at 500 nmol/L and the optimal probe concentration was 280 nmol/L. The minimum detection limit was 10 1 copies/μL, and the minimum clinical positive samples with a Ct value of 36.027 could be detected, and the result of repeated experiments were consistent. The method has no cross-reaction with other viral nucleic acids. The detection rate of clinical positive samples was 93.33%, which was almost identical to that of qPCR. Conclusions:This method is simple to operate with high sensitivity, strong specificity, low requirements for experimental conditions, visual detection result, and can detect VZV nucleic acid in samples within 20 minutes, which is a rapid VZV detection method that can be considered for clinical use for detection.

Objective·To construct a probiotic(Escherichia coli Nissle1917,EcN)system(EcN@PVA-ALG)loaded on polyvinyl alcohol(PVA)/alginate(ALG)hydrogel(PVA-ALG)rich in negative hydroxyl groups,and to explore its colonization in the inflammatory site of colon and its therapeutic effect on dextran sulfate sodium salt(DSS)-induced inflammatory bowel disease(IBD).Methods·EcN suspension was added to the PVA-ALG hydrogel,and then EcN@PVA-ALG hydrogel probiotic complex was obtained after screening and centrifugation.The synthesis of PVA-ALG hydrogel was verified by rheometer.The surface charge of EcN@PVA-ALG was detected by potentiometer and the load of EcN on PVA-ALG was observed by fluorescence microscope.The absorbance of EcN@PVA-ALG at 600 nm was detected by enzyme labeling instrument.Meanwhile,the bacterial plate count of EcN@PVA-ALG complex suspension was taken to study the growth activity of EcN in EcN@PVA-ALG.The CCK-8 kit was used to assess the inhibitory ability of EcN@PVA-ALG on HEK cell proliferation.In vivo imaging system(IVIS)was used to firstly analyze the enrichment of PVA-ALG on inflammatory colon to study its inflammatory targeting property;then EcN was loaded on PVA-ALG,and IVIS was used to observe the enrichment of EcN@PVA-ALG on inflammatory colon to study its ability to colonize the inflammatory site.To establish the model of IBD mice induced by DSS,EcN@PVA-ALG group(n=5)was given 1×108CFU EcN@PVA-ALG every day for 5 d,and PVA-ALG group,EcN group,PBS group and healthy control group with 5 mice were set up.During the treatment,the body mass of the mice was recorded every day.After treatment,the colonic tissue was taken,and the length of colon was measured.The disease activity index(DAI)score was graded.The levels of inflammatory cytokines,including tumor necrosis factor-α(TNF-α),interleukin(IL)-6,IL-10 and transforming growth factor-β(TGF-β)were detected,and the pathological evaluation of colonic tissue was made by H-E staining.Results·Both PVA-ALG and EcN@PVA-ALG were negatively charged.EcN was successfully loaded onto PVA-ALG and PVA-ALG did not affect the growth viability of EcN,which contributed to the subsequent colonization of inflammatory colons.PVA-ALG had a favorable safety profile on normal cells.Compared with healthy controls,PVA-ALG had more than 2-fold enrichment effect on inflammatory colon tissue.In vitro and in vivo experiments revealed that EcN@PVA-ALG complex loaded with EcN had 8 times higher enrichment effect on inflammatory tissue than EcN without any modification.After EcN@PVA-ALG treatment,the body weight of mice recovered rapidly.The increase of DAI was significantly inhibited.The length of colon was similar to that of healthy mice.The levels of TNF-α and IL-6 decreased,while the levels of IL-10 and TGF-β increased.The crypt structure of colon tissue recovered.Conclusion·Compared to unmodified EcN,EcN@PVA-ALG promotes the colonization of EcN at inflammatory sites of colon and allows it to exert better efficacy on treating DSS-induced IBD.

Secondary caries is one of the main reasons that affect the service life of the restoration. Compared with primary caries, secondary caries have some particularities in etiology, disease progression, clinical manifestation, clinical diagnosis, treatment and prevention. Starting from the above aspects, combined with the latest basic and clinical research on secondary caries, this paper summarizes and analyzes its pathogenesis and prevention strategies, which will lay a certain foundation for in-depth understanding of secondary caries and promoting its clinical prevention and treatment.

Endodontic infection control is crucial to successful root canal treatment. Irrigation is the key step in endodontic procedures, and the application of root canal irrigation and disinfection medications play an important role. How to enhance antibacterial effects and functions in removing tissues while maintaining biocompatibility is a hot topic in endodontics. Currently, insights to address this issue can be split into two categories: one, the modification or combination of conventional endodontic irrigation solutions, and two, the development of novel endodontic irrigation solutions with new technologies and materials, for instance, nanomaterials and natural exacts. However, conventional endodontic irrigation solutions, such as sodium hypochlorite and chlorhexidine, are still the first choice in clinical practice. Most novel endodontic irrigation solutions remain at the pre-clinical laboratory stage. Clinical research and relevant data are required to determine whether various methods can improve endodontic irrigation. From basic research to clinical application is the direction for advancing to the next stage. The present article focuses on research progress on endodontic irrigation, especially concerning its antibacterial mechanism, characteristics and efficacy, to provide a reference for future clinical translation.