The epidemic of COVID-19 has lasted for nearly a year, the number of confirmed cases worldwide is still rising, and the trend of the epidemic is unclear. How will be the further development of COVID-19 epidemic? What is the current status of research on new drugs for coronary virus disease? Will the vaccine currently used change the epidemic pattern? In the context of the normalization of the epidemic, whether the epidemiology of other respiratory viruses will change? This article will discuss and analyze these hot and difficult issues.

Objective To explore the mechanism of Wumei pill on ulcerative colitis(UC)in mice based on the anti oxidative stress pathway of nuclear factor erythroid 2-related factor 2(Nrf2)/antioxidant response element(ARE).Methods Seventy SPF male C57BL/6 mice were randomly divided into the control group,the UC group,the mesalazine group(MES group,0.82 g/kg MES),the low dose Wumei pill group(WMW-L group,5 g/kg crude drug),the middle dose Wumei pill group(WMW-M group,10 g/kg crude drug),the high dose Wumei pill group(WMW-H group,20 g/kg crude drug)and the high dose Wumei pills+Nrf2 inhibitor ML-385 group(WMW-H+ML-385 group,Wumei pills crude drug 20 g/kg+20 mg/kg ML-385),with 10 rats in each group.The disease activity index(DAI)score and colonic mucosa injury score were performed in mice after the last administration.Pathological changes of colonic mucosa in mice were observed by HE staining.The levels of interleukin(IL)-1β,tumor necrosis factor-α(TNF-α)and IL-6 in serum and colon tissue of mice were measured by enzyme-linked immunosorbent assay(ELISA).The content of malondialdehyde(MDA)in serum and colon tissue of mice was determined by thiobarbituric acid colorimetry(TBA).The activity of superoxide dismutase(SOD)in serum and colon tissue of mice was measured by xanthine oxidase method.The activity of glutathione peroxidase(GSH-px)in serum and colon tissue of mice was determined by direct method with dithiodinitrobenzoic acid(DTNB).The positive expression of Nrf2 in colon tissue of mice was observed by immunohistochemistry.The expression of heme oxygenase-1(HO-1)and NAD(P)H:quinone oxidoreductase-1(NQO1)proteins in colon tissue of mice were detected by Western blot assay.Results Compared with the control group,the DAI score,colonic mucosa injury score,colonic histopathology score,levels of IL-1β,TNF-α,IL-6 and MDA in serum and colonic tissue,and expression levels of Nrf2,HO-1 and NQO1 protein in colonic tissue of mice were increased in the UC group,levels of SOD and GSH-px in serum and colon tissue decreased(P＜0.05),the colon mucosa of mice was seriously damaged.Compared with the UC group,changes of corresponding indexes were contrary to the above in the MES group,the WMW-M group and the WMW-H group.However,the expression levels of Nrf2,HO-1 and NQO1 proteins in colon tissue were increased(P＜0.05),and the damage of colon mucosa in mice was alleviated.Changes of the above indexes were dose-dependent in the WMW-L group,the WMW-M group and the WMW-H group.There were no significant differences in the above indexes between the WMW-H group and the MES group.ML-385 attenuated the improvement effect of high dose Wumei pill on colon mucosa injury.Conclusion Wumei pill may alleviate the colon mucosal damage of UC mice by activating Nrf2/ARE antioxidant stress pathway.

Objective: To investigate the association of sleep quality, depressive symptoms and their interaction with non suicidal self injury (NSSI) among rural middle school students, so as to provide a reference for early prevention and control of NSSI among rural middle school students. Methods: A multi stage cluster sampling method was used to randomly select four rural middle schools in Xuzhou, Jiangsu Province. A total of 1 723 middle school students were investigated according to the principle of grade stratification and class random selection. Paper questionnaires (including demographic factors, Non Suicidal Self Injury Short Scale, Pittsburgh Sleep Quality Index, Patient Health Questionnare-9) were used to conduct the questionnaire survey. Logistic regression model was used to analyze the association of sleep quality, depressive symptoms and their interaction with NSSI among rural middle school students. Results: Totally 30.5% of middle school students had NSSI. Univariate results showed that girls (33.0%) had a higher incidence of NSSI than boys(27.3%), and those with sleep disorders and depressive symptoms had a higher incidence of NSSI, which was 46.8%, 43.6%. The results of multivariate Logistic regression showed that the risk of NSSI in students with sleep disorder was 1.80 times that in those without sleep disorder( OR 95%CI=1.42-2.28, P <0.01). The risk of NSSI in students with depressive symptoms was 3.32 times higher than that in those without depressive symptoms( OR 95%CI=2.60-4.24, P <0.01). The interaction results showed that there was additive interaction between sleep disturbance and depressive symptoms on the occurrence of NSSI behavior in rural middle school students, and the relative excess risk, attributable proportion and synergy index were 1.80, 0.30 and 1.57, respectively. Conclusion Sleep disorder and depressive symptoms are risk factors for NSSI among rural middle school students, and there is additive interaction between them.

Objective: To understand the relationship between childhood abuse and uncertainty stress among college students and their interaction with depressive symptoms, so as to provide evidence for psychological intervention among college students. Methods: A total of 1 830 college students from Xuzhou, Nanjing and Wuhan were selected by multistage stratified cluster random sampling method to conduct a questionnaire survey from March to May 2021 using Adverse Childhood Experience Scale, Uncertainty Stress Scale, and 10-Item Center for Epidemiological Studies Depression Scale. Results: Overall, 361 (19.73%), 507 (27.70%) and 607 (33.17%) college students had childhood abuse experiences, high uncertainty stress and depressive symptoms respectively. After controlling for confounding factors, multivariate Logistic regression analysis showed that the risk of depressive symptoms in college students with childhood abuse experiences was 2.84 times higher than those without childhood abuse experiences ( OR= 2.84 , 95%CI =2.17-3.71). The risk of depressive symptoms among college students with high uncertainty stress was 7.88 times higher than those without high uncertainty stress ( OR=7.88, 95%CI =6.21-9.99). The results of interaction analysis showed that childhood abuse and uncertainty stress had no multiplication interaction but additive interaction on depressive symptoms of college students: RERI (95% CI )=12.73(3.24-22.23), AP (95% CI )=0.57(0.37-0.76), S (95% CI )=2.47(1.53-3.98). Conclusion High uncertainty stress and childhood abuse have additive interaction on depression symptoms of college students. Eliminating childhood abuse and scientific management of uncertainty stress can reduce the risk of depressive symptoms among college students.

Objective: To compare the reliability of Internet Addiction Impairment Index (IAII), Revised Chen Internet Addiction Scale(CIAS-R)-Taiwan Revision, CIAS-R-Mainland Revision, Young Diagnostic Questionnaire (YDQ) and the consistency of Internet addiction using the four scales in college students. Methods: A total of 1 004 undergraduates from 3 universities in Hefei were selected to measure the tendency of internet addiction simultaneously using the four scales, and 122 students were re tested two weeks after the initial assessment. Correlation coefficient, coincidence rate and Kappa value were used to analyze the consistency of the four scales. Analysis of variance, t test and Logistic regression were used to determine the consistency of the factors related to internet addiction scale. Results: The reliability of the four Internet addiction scales were greater than 0.7( P <0.01). The correlation coefficient among all scales was greater than 0.5( P <0.01). The agreement between YDQ and CIAS-R-Mainland Revision was 0.87. The Kappa value of YDQ and CIAS-R-Taiwan Revision in the consistency analysis was 0.51( P <0.01), the Kappa value between the other scales was less than 0.5. Results showed that the four scales were consistent in Internet addiction prevalence by gender, grade and major, while CIAS-R-Taiwan Revision and YDQ were not consistent with the other two scales in sleep disorder. Conclusion The four Internet addiction scales all have good reliability, while low agreement in Internet addiction assessment, suggesting further improvement and revision in Internet addiction scales.

Objective: To explore the mediating role played by college students social anxiety and social support in the relationship between internet addiction and depression. Methods: A cluster random sampling method was used to conduct a questionnaire survey among 3 536 college students in three higher vocational colleges in Anhui Province. The content included general demographic characteristics, depression, Internet addiction, social support, and social anxiety. The Process program was used to mediate and analysis of regulation. Results: Among the survey subjects, 1 552(43.90%) had depressive symptoms, including 561(45.65%) boys and 991(42.96%) girls.The total score of Internet addiction was significantly positively correlated with depression score(r=0.30, P<0.01); social anxiety(social fear, social avoidance) was positively correlated with depression(r=0.24, 0.27, P<0.01); social support(subjective support, objective support, support utilization) was significantly negatively correlated with depression(r=0.25, -0.23, -0.17, P<0.01). Conditional process analysis shows that social anxiety had a mediating role between internet addiction and depression(c'=0.06, P<0.01), and that Internet addiction and social anxiety were regulated by social support(β=-0.00，P=0.02). Conclusion By increasing the social support of college students to improve social anxiety, it might help to reduce the depression of college students caused by Internet addiction.

Objective To assess the clinical value of cross raft screws technique in preventing postoperative collapse of tibial plateau fracture.Methods From September 2014 to November 2017,data of 14 patients with tibial plateau fracture who were treated by cross raft screws technique were retrospectively analyzed.There were 9 males and 5 females aged from 30-65 years old (average,44.4± 1.7 years).There were 8 patients that the thickness of subchondral cancellous bone measured preoperatively by CT data was less than 4 mm,and 6 patients that the thickness of subchondral cancellous bone measured intraoperatively was less than 4 mm.1/4 tubular plate was placed along the anterior rim of lateral tibial plateau,and the 3.5 mm cortical bone screws were fixed as bamboo raft from anterior to posterior through the plate.The collapse of tibial plateau after surgery were measured by CT scan after union of the fracture.The function of knee was evaluated by Rasmussen Anatomical and Functional Grading.Results The time of tubular plate procedure was 18 to 35 min (average,24.1±5.4 min).All 14 patients were successfully followed-up for 13.8±5.1 months.The height of collapse preoperatively by CT scan was 5-21 mm (average,8.00± 1.40 mm).3 days after the operation,the height between articular line and lateral articular surface was 0-2 mm (average,0.80±0.06 mm).Compared with CT data preoperatively,the collapse was corrected postoperatively that was proved by CT scan (P＜ 0.05).After the fracture was healed,according to CT data,the height between articular line and lateral articular surface was 0-2 mm (average,0.70±0.08 mm).Compared with CT data postoperatively,there was no postoperative collapse happened (P=0.466).The position and length of nails were placed appropriately.The average healing time of fracture was 3.6 months.There were no infection,nonunion and pain of tendon happened.The plate could be touched subcutaneously in 2 patients,who had no discomfort feelings.The patient's postoperative Rasmussen Anatomical Grading were 13-18 (average,16.7),including 8 cases excellent and 6 cases good.The postoperative Rasmussen Functional Grading was 18-28 (average,25.7),including 11 cases excellent and 3 cases good.Conclusion The cross raft screws technique is a good way to prevent the postoperative collapse of the lateral articular surface of tibial plateau.

Objective To study the prevalence trends and etiology of hand,foot,and mouth disease (HFMD) in hospitalized children.Methods The clinical data of 11 510 cases of children hospitalized with HFMD from 2008 to 2017 in Department of Infection Diseases of Kunming Children's Hospital were collected,and to retrospectively analyze the characteristics,time distribution and pathogen distribution of the cases.Results Of the 11 510 children with HFMD,6 100 were male and 5 410 were female.There were 9 814 cases under 3 years old,1 696 over 3 years old.HFMD occurred throughout the year.The peak months of the disease were April to July,with the time distribution of single peak.There were 4 690 severe cases and 3 452 critical cases,accounting for 70.34％.The main pathogens detected were enteroviruses A71 (EV-A71),coxsackievirus A16 (CV-A16) and other enteroviruses (EV),with 3 803 cases (36.02％),1 122 cases (10.63％) and 3 401 cases (32.21％) respectively.EV-A71 and CV-A16 infections dominated from 2008 to 2013,while EV-A71 and other EV infection dominated from 2014 to 2017.Conclusions EV-A71,CV-A16 and other EV are the main pathogens of HFMD in Kunming.Critical HFMD cases are mainly caused by EV-A71 infection.

Objective:To analyze the risk factors of deep venous thrombosis (DVT) in patients with tibial plateau fracture during preoperative period.Methods:From July 2017 to October 2019, a total of 264 patients undergoing surgeries of tibial plateau fractures were enrolled. Duplex ultrasonography (DUS) during hospitalization was used to screen for DVT of the bilateral lower extremities. Patients were divided into DVT group and non-DVT group according to results of DUS. Data on demographics, comorbidities, injury-related data, fracture type, laboratory biomarkers were collected and compared between groups with and without DVT.Results:The incidence of preoperative DVT was 39.0% (103/264) among 264 patients with traumatic tibial plateau fractures, and distal thrombosis predominated in DVT group. There were 103 cases in DVT group. 55 were males and 48 were females. The average age was 54.00±11.12. According to the Schatzker classification of tibial plateau fractures, 7 cases belonged to type I, 37 to type II, 2 to type III, 11 to type IV, 29 to type V, and 17 to type VI. There were 161 cases in non-DVT group. 89 were males and 72 were females. The average age was 48.57±13.25. According to the Schatzker classification of tibial plateau fractures, 23 cases belonged to type I, 76 to type II, 2 to type III, 10 to type IV, 33 to type V, and 17 to type VI. Univariate analysis showed that age ( t=3.451, P=0.001), the type of tibial plateau fracture ( χ2=8.314, P=0.004), D-dimer ( χ2=18.552, P<0.001), APTT ( t=2.869, P=0.004), ALB ( t=2.292, P=0.023) and Hb ( t=1.983, P=0.048) were statistically different than those in non-DVT group. Multivariate analysis showed age ( OR=1.033, 95% CI: 1.009, 1.058; P=0.007), the type of tibial plateau fracture ( OR=1.829, 95% CI: 1.014, 3.299; P=0.045) and D-dimer ( OR=1.914, 95% CI: 1.057, 3.464; P=0.032) were independent risk factors. Conclusion:The incidence of DVT in patients with tibial plateau fractures during preoperative period is high, and distal thrombosis is the main part of venous thrombosis of lower extremity. The type of tibial plateau fracture, age and the level of D-dimer are independent risk factors of preoperative DVT in patients with tibial plateau fractures.

Objective:To study the influence of Mei mini maze procedure for atrial functional mitral regurgitation.Methods:The data of 33 patients with atrial fibrillation and atrial functional mitral regurgitation from January 2017 to June 2020 were retrospectively analyzed. All patients received Mei mini maze procedure for atrial fibrillation. The procedure is carried out thoracoscopically through the left thoracic approach. The ablation of atrial fibrillation includes bilateral circumferential pulmonary vein ablation, isolation of the left atrium posterior wall, left atrial appendage resection, ablation of Marshall's ligament and autonomic ganglion, etc. Follow-up was conducted by outpatient follow-up and telephone. Postoperative heart rhythm was recorded by the patient's symptoms, electrocardiogram, 24 h holter and other examinations. Postoperative mitral valve lesions were obtained by echocardiography.Results:33 patients successfully completed the operation. There was no conversion to thoracotomy and no perioperative death. Thirty patients(90.9%) maintained sinus rhythm at discharge. Before discharge, 16 patients had no mitral regurgitation in echocardiography, 8 patients had mild mitral regurgitation, and 9 patients had moderate mitral regurgitation. Follow-up was 1-4 years after discharge, with a mean of(2.6±1.1) years. Sinus rhythm was maintained in 23 patients(69.7%). 17 patients had no mitral regurgitation, 9 had mild mitral regurgitation, 6 had moderate, and 1 had severe mitral regurgitation. The degree of regurgitation in 25 patients was reduced compared with pre-operation, 5 patients remained unchanged, and 3 patients mitral regurgitation aggravated. Unreduced atrial functional mitral regurgitation was associated with recurrence of atrial fibrillation by Cox multivariate analysis.Conclusion:This study found a close relationship between atrial fibrillation rhythm and atrial functional mitral regurgitation. Most moderate atrial functional mitral regurgitation can be alleviated by effective treatment for atrial fibrillation. It is not recommended that patients with severe atrial functional mitral regurgitation only receive treatment for atrial fibrillation.