Clinical and Immunological Characteristics in COVID-19 Convalescent Patients (preprint)

Objective: The immune responses of COVID-19 convalescent patients have not been well described. Methods Blood from thirty COVID-19 convalescent patients who were virus-free were collected. Their clinical laboratory findings and SARS-CoV-2-specific humoral and cellular immunity were detected. Results At 283 days after diagnosis of SARS-CoV-2 infection, the levels of clinical laboratory indicators and lymphocyte subtypes returned to normal levels. However, the ratio of memory/naive CD4+ T lymphocytes cells was greater in COVID-19 convalescent patients and severe COVID-19 convalescent patients, when compared with that in healthy blood donors (P=0.0135) and non-severe patients (P=0.0431), respectively. The levels of anti-SARS-CoV-2-IgM (P=0.014), S1-IgM (P=0.0004) and RBD-IgM (P=0.0002) in severe COVID-19 patients were all significantly greater than those in non-severe COVID-19 patients. When the serums of COVID-19 convalescent patients were diluted as 1:125, the predictive of serum neutralization capabilities were persistent in all patients. SARS-CoV-2-specific T cells were generated and maintained in majority of tested convalescent COVID-19 patients, regardless of the severity of disease in acute phase. Conclusion At 283 days after diagnosis of SARS-CoV-2 infection, specific cellular and humoral immunity against SARS-CoV-2 could be detectable. The severity of disease in acute phase cannot affect the strength of cellular and humoral immunity in convalescent phase.

Infection prevention strategy in general hospital under regular epidemic prevention and control

New coronavirus pneumonia spread rapidly all over the world in the first half of 2020, which is a new respiratory disease with strong infectiousness. At present, the epidemic situation in China has been effectively controlled, but the global epidemic situation remains grim, and the National Health Commission has instructed that the prevention and control of new coronavirus pneumonia should become normalized. As outposts for surveillance of public health events, hospitals are an important front in the fight against the epidemic. Therefore, it is very crucial to construct infection prevention and control system actively to contain the outbreak. This paper analyzes and summarizes the normal prevention and control management strategy of Infection Control Branch Management (hereinafter referred to as Hospital Infection-Control Dept) in a certain designated comprehensive third-grade hospital in Guangdong Province and transforms the prevention and control means in emergency state into measures for sustainable development, which also provides basis and reference for Hospital Infection-Control Dept of medical institutions to formulate prevention and control guidelines.

The Establishment of a Financial Crisis Early Warning System for Domestic Listed Companies Based on Two Neural Network Models in the Context of COVID-19

In the context of COVID-19, many companies have been affected by the financial crisis. In order to carry out a comparative study on the accuracy of the company's financial crisis early warning method, this study used RPROP artificial neural network and support vector machine, with 162 listed companies' two-year panel financial indicator data as a model sample, and the test sample established a financial crisis early warning model. The theory of comprehensive evaluation combining two kinds of neural network methods is put forward innovatively. The predicted results can strengthen the supervision of the listed companies with risks by themselves and others and have important economic and social significance to ensure the stable operation of the listed companies, the securities market, and the national economy.