Objective: To understand the epidemiological characteristics of the norovirus epidemics in Haidian District, Beijing Municipality from 2015 to 2022, so as to provide insights into epidemic prevention and control. Methods: The epidemiological characteristics, case data, and laboratory testing of norovirus epidemics were collected in Haidian District from 2015 to 2022, and the temporal distribution, spatial distribution, population distribution, and norovirus detection were analyzed using a descriptive epidemiological method. Results: A total of 208 norovirus epidemics involving 3 530 cases were reported in Haidian District from 2015 to 2022, with a median attack rate of 25.00% (interquartile range, 18.35%). The main pathogens detected were type GⅡ, accounting for 87.98% (183 cases), and the main transmission mode was interpersonal transmission, accounting for 93.27% (194 cases). Norovirus epidemics peaked from March to June and October to December, accounting for 44.71% (93 epidemics) and 44.23% (92 epidemics), and predominantly occurred in schools and preschool institutions, accounting for 51.92% (108 epidemics) and 40.38% (84 epidemics). The median age of norovirus infected cases was 8 (interquartile range, 13) years. There were 1 920 males and 1 610 females, with a ratio of 1.19︰1. The positive rates of case specimens, key population specimens and environment smeared specimens in epidemic units were 74.32%, 13.91% and 5.86%, respectively. Conclusions The norovirus epidemics in Haidian District from 2015 to 2022 was mainly caused by type GⅡ and spread from person to person. The epidemics peaked in winter and spring, and schools and preschool institutions were the key units of prevention and control.

Objective To explore whether low-dose occupational ionizing radiation exposure can affect the prevalence of lens opacity.Methods Annual occupational health checkup data of 1 007 radiation workers was taken from a provincial medical institution for the purpose of statistical analysis.Logistic regression analysis was used to estimate occupational exposure odds ratios (OR) of lens opacity,adjusted for age,gender and length of service.Eye lens opacity was grouped into cortical,nuclear and posterior subcapsular opacity according to the position of the opacity occurrence site.Opacity occurred in any one of the both eye lens was recorded as turbidity.Results Only 730 cases coupled with complete information could be used in the statistical analysis.The rate of lens opacity for all the radiation workers was 10.27％.The rates of lens opacity by exposure group were estimated to be 9.07％ for radiation diagnosis and therapy group,11.11％ for intervention group,18.18％ for nuclear medicine group,and 9.33％ for industrial application group,respectively.Compared with those in the radiation diagnosis and therapy group,the workers engaged in intervention medicine,or nuclear medicine,were more likely to suffer from the lens opacity in posterior subcapsular position.The OR and its 95％ confidence intervals were 3.00 (1.23-7.33),4.12 (1.68-10.11) for the workers in intervention medicine or nuclear medicine group.Conclusions Medical radiation workers,who were exposed to long-term low-dose of ionizing radiation,especially those who engaged in intervention or nuclear medicine,were at significantly higher risk to develop lens opacity.

Objective To evaluate the feasibility of induction with sevoflurane-midaaolam-remifentanil for tracheal intubation without muscle relaxants in patients with huge mediastinal tumor.Methods Twenty-two ASA Ⅰ-Ⅲ patients with huge mediastinal tumor,aged 22-64 yr,weighing 48-76 kg,scheduled for surgery under general anesthesia,were enrolled in this study.Anesthesia was induced with iv injection of midaaolam 0.03 mg/kg and inhalation of 8％ sevoflurane through a mask.Sevoflurane was inhaled at the initial concentration of 8％,followed by decrement of 2％ every 30 s until 4％.When the eyelash reflex disappeared,remifentani1 2 μ g/kg was injected slowly over I min and sevoflurane inhalation was stopped 30 s later.The patients were mechanically ventilated after tracheal intubation.MAP and HR were recorded before induction and immediately before and 1 min after inlubation.The time of disappearance of eyelash reflex was recorded.The inlubation condition was evaluated using VibyMogensen score.Results The time period from sevoflurane inhalation to disappearance of eyelash reflex was(110 ± 14)s.The success rate of tracheal intubation at the first attempt was 86％.The position of the glottis was higher in 2 patients,and tracheal intubation was successfully performed under the guide of fiberoptic bronchoscope.The satisfactory intubation conditions were found in 86％ of cases.Compared with that before anesthesia induclion,MAP and HR were significantly decreased immediately after intubation and at 1 min after intubation(P ＜ 0.05).SpO2 ＞ 95％ in all patients.BIS was maintained at 45-55 during the period(before intubation until 1 min after intubation).Conclusion Induction with sevoflurane-midazolam-remifenlail is rapid and smooth,provides good conditions for intubation and can be applied to tracheal intubation without muscle relaxants in patients with huge mediastinal tumor.

Objective To evaluate the feasibility of induction with sevoflurane-midazolam-remifentail for tracheal intubation without muscle relaxants in neck brake patients.Methods Forty ASA Ⅰ or Ⅱ patients with cervical spine fracture with dislocation,aged 13-68 yr,scheduled for surgery under general anesthesia,were enrolled in this study.Anesthesia was induced with iv injection of midazolam 0.03 mg/kg and inhalation of 5%sevoflurane through a mask.Sevoflurane was inhaled at the initial concentration of 5%,followed by decrement of 1% every 30 s until 3%.When the eyelash reflex disappeared,remifentanil 2 μg/kg was injected slowly over 45s and 30 s later sevoflurane inhalation was stopped.The patients were mechanically ventilated after tracheal intubation.The time of disappearance of eyelash reflex was recorded.The intubation condition was evaluated using VibyMogensen score.Results All patients were successfully intubated at the first attempt.The time period from sevoflurane inhalation to disappearance of eyslash reflex was(69 ± 4)s.Coughing occurred in 3 cases during intubation.The satisfactory intubation conditions were found in 100% of cases.SpO2 ＞ 95% in all patients.BlS was maintained at 45-55 during the period(before intubation until 3 min after intubation).Conclusion Induction with sevoflurane-midazolam-remifentail is rapid and smooth,provides good conditions for intubation and can be applied to tracheal intubation without muscle relaxants in neck brake patients.

Objective To measure the concentration of serum transthyretin (TTR) of patients with different stages of diabetic retinopathy (DR).Methods A total of 176 patients with diabetes mellitus were included in this study.There were 104 males and 72 females.The patients aged from 21 to 74 years,with the mean age of(56± 11) years.The diabetes duration raged from 1 to 30 years,with the mean diabetes duration of (10 ± 7) years.The HbA 1C was 5.2％-14.1％,with the mean HbA 1C of (8.6 ± 2.0)％.According to the fundus examination,58 patients had DR (33.0％),but the other 118 patients not (67.0％).For these DR patients,10 patients were in stage Ⅰ (5.7％),26 patients in stage Ⅱ (14.8％),8 patients in stage Ⅲ (4.5％),and 14 patients in stage Ⅳ (8.0％).The concentration of serum TTR was measured by enzyme-linked immunosorbentassay kit.The differences in the concentration of serum TTR between different DR stages were compared.Bivariate analysis was used to analyze the influencing factors of TTR.Results The concentrations of serum TTR of the patients without DR or with DR of stage Ⅰ to Ⅳ were (224.96±65.47),(383.68± 102.99),(247.44±63.21),(228.2 ± 45.89),(189.34± 70.12) mg/L,respectively.The difference between different DR stages was statistically significant (F=14.690,P＜ 0.001).Bivariate analysis showed that the concentration of TTR was correlation to DR (r=0.179,P=0.017).There was no correlation between the concentration of TTR and diabetes duration (r=-0.027,P=0.727),hypertension (r=0.018,P=0.810),hyperlipoidemia (r=0.101,P=0.182),and the use of insulin (r=-0.032,P=0.675).Conclusion The concentration of serum TTR was increased in early DR patients,and gradually decreased with the progression of DR.The concentration of TTR is correlated to DR.