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Many healthcare workers (HCWs) have been confirmed to be infected with SARS‐CoV‐2 in China. A retrospective, single‐center study was conducted. The median age of the 132 HCWs with COVID‐19 was 32 years, with 92 (69.7%) being females. There were 47 (35.6%) doctors, 72 (54.6%) nurses, and 13 (9.9%) other HCWs. Ten of the 132 patients (7.6%) had underlying diseases. The most common symptoms of illness onset were fever (70, 53.0%), cough (66, 50.0%), and fatigue (58, 43.9%). All patients were categorized into mild or moderate COVID‐19 type on admission to hospital, and five (3.8%) progressed to the severe COVID‐19 type. Sixty‐six HCWs patients were included in both the early and later discharged group. In the logistic analysis, the later discharged patients had a longer time for illness onset to hospital admission (per 1 day; OR, 1.10; 95% CI, 1.03–1.18; p =.006), a higher proportion of >3 onset symptoms clustering (OR, 3.11; 95% CI, 1.27–7.62; p =.01), and a higher percentage of other HCWs (OR, 6.20; 95% CI, 1.49–25.80; p =.01). HCW patients were young female nurses with fewer comorbidities, and most were mild or moderate COVID‐19 type. The later discharged patients exhibited characteristics of longer time for illness onset to hospitalization and clustering of onset symptoms. [ABSTRACT FROM AUTHOR]

Abstract: In this paper, we use canonical correlation analysis (CCA) method to investigate the semi-diurnal tidal winds in mesosphere and low thermosphere (MLT) region, observed by a newly installed meteor radar at Wuhan (30.6°N, 114.4°E), during the year 2002. In general, 4(3) effective semi-diurnal tidal pairs of patterns are obtained, which represent ∼2/3 total variances of the origin data set. These patterns are expected to be corresponding to the atmospheric oscillations within the semi-diurnal frequency band excited or modulated by different sources, i.e., the seasonal variations, the modulations by the planetary wave oscillations or the solar 27-day activity. Among all the patterns, the 1st pattern, which represents ∼1/3 of total variances, is the most notable. Its amplitudes show maximum values in spring and autumn, and the vertical wavelengths are longer in summer and shorter in winter, which is in line with the results obtained from traditional harmonic analysis. The vertical wavelengths of the higher order patterns (∼50km) suggest the classic semi-tidal mode S(2,4)/S(2,5) is dominant. [Copyright &y& Elsevier]

Abstract: Neural networks (NNs) have been applied to ionospheric predictions recently. This paper uses radial basis function neural network (RBF-NN) to forecast hourly values of the ionospheric F 2 layer critical frequency(foF 2), over Wuhan (30.5N, 114.3E), China. The false nearest neighbor method is used to determine the embedding dimension, and the principal component analysis (PCA) is used to reduce noise and dimension. The whole study is based on a sample of about 26,000 observations of foF 2 with 1-h time resolution, derived during the period from January 1981 to December 1983. The performance of RBF-NN is estimated by calculating the normalized root-mean-squared (NRMSE) error, and its results show that short-term predictions of foF 2 are improved. [Copyright &y& Elsevier]