Objective To introduce a kind of operative technique in repair for the prolapse of the anterior mitral valve leaflet.Methods From January 2004 to October 2010,the operation of chordal transfer based on theedge-to-edge technique was performed in 18 cases with serious mitral valve regurgitation because of prolapse of the anterior leaflet.First,the edge-to-edge suturing was performed at the free edge of the prolapsed anterior leaflet with corresponding posterior leaflet.After that,quadrangular resection was performed to transfer these segments of posterior leaflet with its attached chordae.At last,the posterior leaflet was repaired after a quadrangular resection which would be much easier for the surgeons.After the operation,echocardiography was performed in each patient before discharge and at the time of follow-up.Results All patients survived after the operation,1 case required the rnitral valve replacement because of anterior leaflet performation occurring 3 days after the operation,1 case with hemoglobinuria and 1 case with low cardiac output,who all got symptomatic treatment afterwards.All the other patients were well discharged.At the time of follow-up,all of the patients were in NYHA functional class I.In all these patients,pre-discharge and follow-up echocardiography showed neither stenosis nor significant regurgitation of the mitral valve:the cross-sectional area of the mitral valve was 2.8-4.8 (3.78 +0.52) cm2,the mean regurgitation area was (0.45 +0.22) cm２.At the same time,both dimension of left atrium and left ventricular reduced significantly [ left atrium diameter:pre-operation ( 48.26 + 11.12 ) mm,post-operation ( 37.57 ± 9.56) mm (P ＝ 0.028 );the end-diastolic diameter of the left ventricular:pre-operation(61.43 ± 8.24) mm,post-operation (42.35 ±10.79) mm (P＝0.008)].Conclusion Chordal transfer based on the edge-to-edge technique provides good results for repair of anterior leaflet prolapse.

Objective: To investigate the origin of infection and risk factors of a case with SARS-CoV-2 infection associated with overseas countries in the Ningbo-Zhoushan Port, Zhejiang Province, so as to provide the evidence for improving the COVID-19 control measures at ports. Methods: Ningbo Center for Disease Control and Prevention ( CDC ) and Beilun CDC conducted case finding and epidemiological surveys immediately after being informed. The general information, history of vaccination and the travel during the latest 14 days were collected from the positive case, and all close contacts were tracked. Saliva samples were collected for SARS-CoV-2 nucleic acid testing and whole-genome sequencing, and the sequencing results were aligned with the GISAID's EpiCoV database. The origin of infection and transmission route of the positive case was investigated. Results: A case was identified positive for SARS-CoV-2 nucleic acid during company M's routine screening in the Ningbo-Zhoushan Port on August 10, 2021, and was confirmed positive for SARS-CoV-2 nucleic acid by Beilun CDC and Ningbo CDC on August 11. Whole-genome sequencing showed SARS-CoV-2 B.1.617.2 ( Delta ) variant, which shared the highest homology with the virus sequence uploaded by Russia on June, 2021 ( Russia/MOW-RII-MH27356S/2021 ). The case was a bundling worker for overseas container ships, and reported communicated with foreign boatmen and contacted materials without protected interventions on the SINOKOR AKITA Container Ship between August 4 and 5, 2021. This ship anchored at Vladivostok, Russia from July 27 to 29, anchored at Ningbo Harbor on August 4, and departed on August 5. Then, 11 boatmen from this ship were tested positive for SARS-CoV-2 nucleic acid on August 8. One asymptomatic case was reported in this epidemic; 254 close contacts and 617 secondary close contacts were identified, and all were tested negative for SARS-CoV-2 nucleic acid. No new cases with SARS-CoV-2 infections were detected until August 25, 2021, and the emergency response was therefore terminated. Conclusions The infection was a sporadic COVID-19 epidemic associated with overseas countries, which was caused by Delta variant infection through contacts with foreign boatmen or materials by a bundling worker in Ningbo-Zhoushan Port; fortunately, no epidemic spread occurred. Intensified closed-loop management and increased frequency of SARS-CoV-2 nucleic acid test among high-risk populations, and improving the precision and rapid emergency treatment of COVID-19 epidemics are required for the containment of COVID-19 at ports.

Objective: To Assess occupational health risks of exposuring to low concentrations (lower than occupational exposure limit, OEL) benzene, toluene and Xylenes. Methods: Qualitative evaluation, semi-quantitative evaluation and quantitative evaluation from guidelines for occupational health risk assessment of chemicals in the workplace were conducted to assess occupational health risks exposure to benzene compounds in different workplaces of 5 manufacturing enterprises, respectively. Results: Concentrations of benzene, toluene and Xylenes in all workplaces were lower than OEL. Qualitative evaluation showed that occupational health risk level was 4 exposure to benzene and Xylenes in all workpalces, while 2 exposure to toluene. Semi-quantitative evaluation showed low level (2 of 5) risks in all workplaces exposured to benzene compounds excepted 4 workpalces exposured to benzene, the latter was moderate (3 of 5) . Quantitative evaluation gave unacceptable carcinogenic risk (higher than 10^-4) of benzene in the wood toy manufactory, and the highest risk was (1.48~5.26) ×10^-4. The occupational health risks of benzene and Xylenes were all unacceptable (HQ>1) in 9 workplaces. Conclusion There still need more attention to occupational health risks exposure to benzene, toluene and Xylenes lower than OEL.