Background SARS-CoV-2 could infect people at all ages, and the viral shedding and immunological features of children COVID-19 patients were analyzed. Methods Epidemiological information and clinical data were collected from 35 children patients. Viral RNAs in respiratory and fecal samples were detected. Plasma of 11 patients were collected and measured for 48 cytokines. Results 40% (14/35) of the children COVID-19 patients showed asymptomatic infections, while pneumonia shown by CT scan occurred in most of the cases (32/35, 91.43%). Elevated LDH, AST, CRP, neutropenia, leukopenia, lymphopenia and thrombocytopenia occurred in some cases, and CD4 and CD8 counts were normal. A total of 22 cytokines were significantly higher than the healthy control, and IP-10, IFN-α2 of them in children were significantly lower than the adult patients. Meanwhile, MCP-3, HGF, MIP-1α, and IL-1ra were similar or lower than healthy control, while significantly lower than adult patients. Viral RNAs were detected as early as the first day after illness onset (d.a.o) in both the respiratory and fecal samples. Viral RNAs decreased as the disease progression and mostly became negative in respiratory samples within 18 d.a.o, while maintained relatively stable during the disease progression and still detectable in some cases during 36~42 d.a.o. Conclusion COVID-19 in children was mild, and asymptomatic infection was common. Immune responses were relatively normal in children COVID-19 patients. Cytokine storm also occurred in children patients, while much weaker than adult patients. Positive rate of viral RNAs in fecal samples was high, and profile of viral shedding were different between respiratory and gastrointestinal tract.

Due to less attention to the English phonetics improvements was paid by high school English teaching, many Chinese university freshmen lack of the most basic phonetics knowledge, for example, their verbal continuous reading is not coherent and their incomplete blasting phonetics is not clear, some freshmen even do not know how to spell words correctly according to their phonetics. This situation has made many negative effects on China’s university English EFL teaching, especially for their improvement of listening comprehension ,but if both teachers and freshmen are aware of this problems, the university English classroom teaching can be effectively improved.

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The distributed and privacy-preserving characteristics of fine-grained smart grid data hinder data sharing, making federated learning an attractive approach for collaborative training among data owners with similar load patterns. However, malicious models can interfere with training in the federated learning aggregation process, making it difficult to ensure the accuracy and safety of the central model in load forecasting. Therefore, we propose a secure aggregation federated learning method for distributed load forecasting based on similarity and distance (Fed-SAD), which effectively eliminates the interference of malicious models by securely aggregating models, thereby ensuring accurate and safe distributed scenario prediction. Experimental results demonstrate that Fed-SAD maintains high accuracy and robustness in both the presence and absence of malicious models, while maintaining data and model security.