Objective To evaluate the practicability of using CRISPR/Cas9 genome editing tech-nology for inhibition of hepatitis B virus ( HBV) replication. Methods Two sgRNA targeting sites were de-signed for the S region of HBV genome. The CRISPR/Cas9 expression plasmids specific for HBV were con-structed and then transfected into a cell line expressing HBV genome(HepG2-N10). The cytotoxicity of cells transfected with different expression plasmids were detected by MTT assay. The levels of hepatitis B surface antigen ( HBsAg ) were determined by using chemiluminescent immunoassay ( CLIA ) . The expression of HBV at mRNA level was analyzed by quantitative real-time PCR ( qRT-PCR) . The qPCR was performed for the detection of extracellular and intracellular HBV DNA. The next-generation sequencing ( NGS) Illumina MiSeq Platform was used to analyze HBV genome editing. Results No significant cytotoxic effects were de-tected in HepG2-N10 cells transfected with different expression plasmids. Compared with the cells carrying pCas-Guide-GFP-Scramble, the levels of HBsAg in the supernatants of transfected cell culture harboring pCas-Guide-GFP-G1 and pCas-Guide-GFP-G2 were decreased by 24. 2% (P<0. 05) and 16. 9% (P>0. 05), respectively. The levels of HBsAg in cells transfected with pCas-Guide-GFP-G1 and pCas-Guide-GFP-G2 were respectively decreased by 16. 4% (P>0. 05) and 32. 1% (P>0. 05) as compared with that of pCas-Guide-GFP-Scramble transfected group. The expression of HBV at mRNA level was inhibited as indica-ted by the results of qRT-PCR. Moreover, the levels of extracellular HBV DNA were respectively suppressed by 23% (P>0. 05) and 35% (P<0. 05), and the levels of intracellular HBV DNA were respectively sup-pressed by 7. 2% (P>0. 05) and 18% (P>0. 05). Different types of insertion/deletion mutation were de-tected in HBV genome by high-throughput sequencing. Conclusion HBV-specific CRISPR/Cas9 system could inhibit the expression of HBV gene and the replication of virus. Therefore, the CRISPR/Cas9 genome editing technology might be used as a potential tool for the treatment of persistent HBV infection.

Objective To study the effect of menopause status and the time of taking tamoxifen (TAM) on endometrial lesions after breast cancer surgery. Methods A total of 330 patients with postoperative vaginal irregular bleeding after breast cancer surgery or endometrial lesions after B ultrasonic from August 2007 to August 2017 in Northern Jiangsu People 's Hospital were retrospectively analyzed, including 180 cases of taking TAM treatment (medicine-taking group), and 150 cases of not taking TAM treatment (non medicine-taking group). The patients were also divided into the menopause group and the premenopausal group. According to the time of taking TAM, the patients were divided into < 2 years group, 2-5 years group and > 5 years group. Chi-square and Fisher test were used to compare the differences. Results The endometrial lesions incidence in the medicine-taking group was higher than that in the non medicine-taking group [84.44 ％ (152/180) vs. 56.00％(84/150);χ2=51.701, P=0.000]. The endometrial lesions rate in the menopause group was higher than that in the premenopause group [medicine-taking group: 69.70 ％ (46/66) vs. 92.98 ％ (106/114), χ2= 17.254, P= 0.000; non medicine-taking group: 46.15 ％ (35/65) vs. 63.53 ％(54/85), χ2 = 4.513, P= 0.034]. For the patients in the menopause group and the premenopause group, the incidence of endometrial lesions for those who took medicine for>5 years [96.00％(48/50), 85.19％(23/27)] was higher than that in the<2 years group and 2-5 years group [78.26％(18/23), 42.86％(6/14);95.12％(39/41), 72.00％(18/25) respectively], and there were statistical differences (χ2=7.619, P=0.022;χ2= 8.070, P= 0.018). The menopause was not correlated with staging, muscular lawyer infiltration and lymph metastasis postoperative (P> 0.05), but with the type of endometrial cancer (P= 0.013); the length of taking medicine was related with the type of endometrial cancer and the lymph metastasis (P=0.027). With the prolonged time of medicine-taking for postmenopause patients, the incidence of type Ⅱendometrial cancer and positive rate of lymph metastasis were also increased. Conclusions Taking TAM after surgery for breast cancer patients increases the risk of endometrial lesions. The longer the patients take the medicine, the greater risk of the lesions take, and the worse the pathological, histological type and prognosis of endometrial carcinoma are, which is more obvious for postmenopausal women who take TAM for more than 5 years.

Objective: To establish a prediction model for infectious disease index（IDI）by autoregressive integrated moving average（ARIMA）,and to provide forcast of infectious diseases to the public. Methods: The data of the percentage of influenza-like illness（ILI）,the incidence rates of hand-foot-mouth disease（HFMD）and other infectious diarrhea（OID）from the 1st week of 2014 to the 14th week of 2018,and Breteau index（BI）from the 1st week of 2016 to the 14th week of 2018 were collected. ARIMA models were built to predict the risk indicators of ILI,HFMD,OID and BI. The weights of the four indicators were evaluated seasonally by the entropy weight method. Then the IDI was calculated and the data of ILI,HFMD, OID and BI from 15th to 19th week in 2018 was used for verification. Results: The forecast was in summer,so IDI=ROUND（0.33×risk index of ILI percentage +0.47×risk index of HFMD incidence +0.10×risk index of OID incidence+0.10×risk index of BI）. The predicted IDI would be 2（less safe）in the whole city and Xiangzhou District,and 1（safe）in Doumen District and Jinwan District. The consistency rates of IDI prediction was 97.50%,95.00%,97.50%,85.00% and 77.50% from 15th to 19th week in 2018,respectively. Conclusion It was feasible to use IDI for short-term risk prediction of infectious diseases.

Objective:To evaluate the detection ability of two kinds of high-throughput method to determine neutralizing antibodies based on a microneutralization test (MNT).Methods:Serum samples were collected from the early phase and follow-up period (117 samples in total) for neutralizing antibody testing. They were tested using MNT, pseudovirus neutralization assay (PBNA), competitive inhibition assay (including enzyme-linked immunosorbent assay (ELISA) and chemiluminescence immunoassay (CLIA)) to evaluate the correlation coefficients and threshold values for the effectiveness of these high-throughput neutralizing antibody assays.Results:The correlation coefficients for PBNA, ELISA, and CLIA relative to MNT were 0.760, 0.778, and 0.725, respectively, for individuals infected with 2019-nCoV. The area under the ROC curve was 0.901 for a cutoff value of 50 for the PBNA assay, 0.934 for a cutoff value of 1∶8 for the ELISA assay and 0.838 for a cutoff value of 1.28AU/ml for the CLIA assay when the threshold value for the microneutralization test was taken as 1: 10 (less than 1: 10 is considered negative).Conclusions:The high-throughput method for the detection of COVID-19 neutralizing antibodies are scientific and feasible, and provide an important technical tool for the regular prevention and control of the epidemic.

OBJECTIVES: At present, removable partial denture is still one of the main restoration methods for dentition defects. However, the trend for digital partial denture is becoming more and more obvious in the field of oral repair. However, there are relatively few studies on digital removable partial denture. The aim of this study is to investigate the effects of 3 processing technologies (precision casting, digital cutting, and 3D printing) on the fitness for the clasps of cobalt chromium alloy and pure titanium removable partial denture, and to provide a theoretical basis for the clinical application of digital removable partial denture. METHODS: Clasps of Co-Cr alloy and pure titanium were produced by 3 different processing technologies (precision casting, digital cutting, and 3D printing). There are 6 groups, including a casting pure titanium group, a casting cobalt chromium group, a cutting pure titanium group, a cutting cobalt chromium group, a printing pure titanium group, and a printing cobalt chromium group ( RESULTS: There was no statistical difference in fitness between the casting pure titanium group and the casting cobalt chromium group ( CONCLUSIONS The cobalt chromium alloy and pure titanium clasps made by precision casting, digital cutting, and 3D printing have good fitness. Under the same process, there is no significant difference between cobalt chromium alloy and pure titanium clasps. The 3D printing pure titanium clasps have better fitness than casting pure titanium and cutting pure titanium clasps, which meet the needs of clinical application.
Chromium Alloys ; Cobalt ; Denture, Partial, Removable ; Titanium

Objective    To analyze the recovery rule of atrial contractility (AC) function after Maze Ⅳ procedure of valvular atrial fibrillation (AF). Methods    In our hospital from March 2016 to April 2018, 103 patients who underwent cryoablation Maze Ⅳ procedure due to mitral valve lesions associated with persistent or long-term persistent AF were enrolled. There were 42 males and 61 females, with an average age of 58.5±9.1 years. Electrocardiogram and echocardiography were followed up at discharge and 1, 3, 6, 12 months after procedure. A multivariate Cox analysis of predictive factors for AC recovery was applied. Results    All the 103 patients were followed up for 1 year. The recovery rate of AC increased gradually after operation. It was not until 3 months after procedure that most of the right atrial contractility (RAC) was accompanied by synchronous recovery of the corresponding left atrial contractility (LAC, Kappa coefficient≥0.40, P<0.05). However, the coexistence of sinus rhythm (SR) and bilateral AC was not consistent well until 1 year after operation (Kappa coefficient≥0.40, P<0.05). One year after procedure, the recovery rates of SR and bilateral AC were 86.4% (89/103) and 66.0% (68/103) respectively. By Cox multivariate regression analysis, longer preoperative AF duration (P=0.040), larger preoperative left atrial diameter (LAD, P=0.003), and AC deletion 3 months after surgery (P=0.037) were predictive factors for AF recurrence in the middle and advanced stages (>3 months) after Maze surgery. At the same time, longer preoperative AF duration and larger preoperative LAD were also negative predictors of middle and late recovery of LAC and bilateral AC (All P<0.05). Receiver operating characteristic curve analysis showed that the best critical value of preoperative AF time and preoperative LAD for prediction of AC recovery was 37 months (sensitivity 99.6%, specificity 76.3%) and 60.5 mm (sensitivity 98.5%, specificity 78.9%), respectively. Conclusion    The recovery of AC after Maze procedure is a dynamic improvement process. Early recovery of AC is beneficial to the stable maintenance of SR in the future. Prolonged duration of AF and enlarged LAD have adverse effects on the outcome of Maze Ⅳ procedure.