[A time-series study on the association of ambient temperature with daily outpatient visits of eczema in Huizhou city].

Objective: To explore the impact of environmental temperature exposure on eczema visits. Methods: Eczema clinic data from January 1, 2016 to December 31, 2019 were collected from the Huizhou Dermatology Hospital, and data on meteorological factors (average daily temperature and relative humidity) for the same period were derived from 86 meteorological stations of the Guangdong Provincial Climate Center. A distributed lag nonlinear model (DLNM) was used to assess the lagged effect of environmental temperature exposure on eczema, and a natural smooth spline function was used to control the nonlinear confounding of humidity. Results: There were 254 053 eczema outpatient visits at the Huizhou Dermatology Hospital within four years, with an average of 173.89 visits per day. The relationship between daily average temperature and the number of visits was non-linear (U shape). The risk of eczema increased by 2.20% (1.19%-3.21%) for every 1 ℃ decrease for the low temperature, and increased by 2.35% (1.24%-3.5%) for every 1 ℃ increase for the high temperature. The effect of high temperature was greater than that of low temperature. In all cases, 1.60% (0.44%-2.68%) of eczema outpatient visits were attributed to low temperature and the attributable number was 4 065 (1 128-6 798), while 6.33% (1.40%-10.87%) of eczema outpatient visits were due to high temperature and the attributable number was 16 082 (3 557-27 616). Conclusion: Both high temperature and low temperature are associated with increased risk of eczema.

[Epidemiological characteristics of local COVID-19 epidemics and control experience in routine prevention and control phase in China].

The COVID-19 pandemic is still ongoing in the world, the risk of COVID-19 spread from other countries or in the country will exist for a long term in China. In the routine prevention and control phase, a number of local COVID-19 epidemics have occurred in China, most COVID-19 cases were sporadic ones, but a few case clusters or outbreaks were reported. Winter and spring were the seasons with high incidences of the epidemics; border and port cities had higher risk for outbreaks. Active surveillance in key populations was an effective way for the early detection of the epidemics. Through a series of comprehensive prevention and control measures, including mass nucleic acid screening, close contact tracing and isolation, classified management of areas and groups at risk, wider social distancing and strict travel management, the local COVID-19 epidemics have been quickly and effectively controlled. The experiences obtained in the control of the local epidemics would benefit the routine prevention and control of COVID-19 in China. The occurrence of a series of COVID-19 case clusters or outbreaks has revealed the weakness or deficiencies in the COVID-19 prevention and control in China, so this paper suggests some measures for the improvement of the future prevention and control of COVID-19.

[Comparison of two epidemic patterns of COVID-19 and evaluation of prevention and control effectiveness: an analysis based on Guangzhou and Wenzhou].

Objective: To compare the epidemiological characteristics of COVID-19 in Guangzhou and Wenzhou, and evaluate the effectiveness of their prevention and control measures. Methods: Data of COVID-19 cases reported in Guangzhou and Wenzhou as of February 29, 2020 were collected. The incidence curves of COVID-19 in two cities were constructed. The real time reproduction number (R(t)) of COVID-19 in two cities was calculated respectively. Results: A total of 346 and 465 confirmed COVID-19 cases were analysed in Guangzhou and Wenzhou, respectively. In two cities, most cases were aged 30-59 years (Guangzhou: 54.9%; Wenzhou: 70.3%). The incidence curve peaked on 27 January, 2020 in Guangzhou and on 26 January, 2020 in Wenzhou, then began to decline in both cities. The peaks of imported COVID-19 cases from Hubei occurred earlier than the peak of COVID-19 incidences in two cities, and the peak of imported cases from Hubei occurred earlier in Wenzhou than in Guangzhou. In early epidemic phase, imported cases were predominant in both cities, then the number of local cases increased and gradually took the dominance in Wenzhou. In Guangzhou, the imported cases was still predominant. Despite the different epidemic pattern, the R(t) and the number of COVID-19 cases declined after strict prevention and control measures were taken in Guangzhou and in Wenzhou. Conclusion: The time and scale specific differences of imported COVID-19 resulted in different epidemic patterns in two cities, but the spread of the disease were effectively controlled after taking strict prevention and control measures.

[Risk assessment and early warning of imported COVID-19 in Guangdong province].

Objective: To assess the imported risk of COVID-19 in Guangdong province and its cities, and conduct early warning. Methods: Data of reported COVID-19 cases and Baidu Migration Index of 21 cities in Guangdong province and other provinces of China as of February 25, 2020 were collected. The imported risk index of each city in Guangdong province were calculated, and then correlation analysis was performed between reported cases and the imported risk index to identify lag time. Finally, we classified the early warming levels of epidemic by imported risk index. Results: A total of 1 347 confirmed cases were reported in Guangdong province, and 90.0% of the cases were clustered in the Pearl River Delta region. The average daily imported risk index of Guangdong was 44.03. Among the imported risk sources of each city, the highest risk of almost all cities came from Hubei province, except for Zhanjiang from Hainan province. In addition, the neighboring provinces of Guangdong province also had a greater impact. The correlation between the imported risk index with a lag of 4 days and the daily reported cases was the strongest (correlation coefficient: 0.73). The early warning base on cumulative 4-day risk of each city showed that Dongguan, Shenzhen, Zhongshan, Guangzhou, Foshan and Huizhou have high imported risks in the next 4 days, with imported risk indexes of 38.85, 21.59, 11.67, 11.25, 6.19 and 5.92, and the highest risk still comes from Hubei province. Conclusions: Cities with a large number of migrants in Guangdong province have a higher risk of import. Hubei province and neighboring provinces in Guangdong province are the main source of the imported risk. Each city must strengthen the health management of migrants in high-risk provinces and reduce the imported risk of Guangdong province.

[Risk assessment of exported risk of COVID-19 from Hubei Province].

Objective: To evaluate the exported risk of COVID-19 from Hubei Province and the imported risk in various provinces across China. Methods: Data of reported COVID-19 cases and Baidu Migration Indexin all provinces of the country as of February 14, 2020 were collected. The correlation analysis between cumulative number of reported cases and the migration index from Hubei was performed, and the imported risks from Hubei to different provinces across China were further evaluated. Results: A total of 49 970 confirmed cases were reported nationwide, of which 37 884 were in Hubei Province. The average daily migration index from Hubei to other provinces was 312.09, Wuhan and other cities in Hubei were 117.95 and 194.16, respectively. The cumulative COVID-19 cases of provinces was positively correlated with the migration index derived from Hubei Province, also in Wuhan and other cities in Hubei, with correlation coefficients of 0.84, 0.84, and 0.81. In linear model, population migration from Hubei Province, Wuhan and other cities in Hubei account for 71.2%, 70.1%, and 66.3% of the variation, respectively. The period of high exported risk from Hubei occurred before January 27, of which the risks before January 23 mainly came from Wuhan, and then mainly from other cities in Hubei. Hunan Province, Henan Province and Guangdong Province ranked the top three in terms of cumulative imported risk (the cumulative risk indices were 58.61, 54.75 and 49.62 respectively). Conclusion: The epidemic in each province was mainly caused by the importation of Hubei Province. Taking measures such as restricting the migration of population in Hubei Province and strengthening quarantine measures for immigrants from Hubei Province may greatly reduce the risk of continued spread of the epidemic.

Separation and preconcentration of MnVII/MnII speciation on crosslinked chitosan and determination by flame atomic absorption spectrometry.

A novel method for the separation and preconcentration of MnVII/MnII with crosslinked chitosan (CCTS) and determination by flame atomic absorption spectrometry (FAAS) has been developed. The adsorption rate of CCTS for MnVII was 98% at pH 3, while MnII was not adsorbed. MnVII was eluted from the CCTS with 10% (m/v) oxammonium hydrochloride and determined by FAAS. MnII was determined from the total manganese present after MnII in the water samples was transformed into MnVII. The detection limit (3 sigma, n = 10) for MnVII was 1.98 micrograms l-1 and the relative standard deviation less than 6.6% at the 10 micrograms l-1 level. The method was applied to environmental water samples with recoveries of between 95-103%.

[AFLP markers of restoring genes of the wild-abortive hybrid rice].

Fertile and sterile pools were set up by bulked segregant analysis (BSA) based on the selection for the highly fertile and highly sterile plants of Shanyou 63 F2 population. The AFLP analysis of the two pools indicated that 64 primer combinations amplified 3,477 stable and clear bands. Exception of the combination E-AGC/M-CAA, all primer combinations had not detected polymorphism between the two pools. It was proved by investigation of two parents, individuals of F2 segregant population, backbone sterile lines and restorer lines that the polymorphic fragment AP1 generated from the primer E-AGC/M-CAA was associated with the restoring gene. AP1 was a single copy detected by Southern blot hybridization. The distance between AP1 and the restoring gene was 4.76 cM.