COVID-19(8) 2019 novel coronavirus(3) 2019-nCoV(3) Coronavirus disease 2019(2) pneumonia.(2) mechanical ventilation(1) immune response(1) recurrence.(1) Bronchoalveolar lavage fluid(1) 2019 novel coronavirus infection(1) antiviral therapy(1) Infection prevention and control(1) Bronchoscope-guided(1) disease severity(1) Diagnosis and treatment(1) Novel coronavirus(1) Cause analysis(1) Influenza,humen(1) renal replacement therapy(1) Lopinavir(1) Oxygenation(1) indications(1) pulmonary rehabilitation(1) Pneumonia(1) Tomography, x-ray computed.(1) military(1) Inflammatory cytokines.(1) Henan province.(1) discharge from hospital(1) Infections in birds(1)