In the clinical data, the changes of RIPK3 and FXR were monitored in the lung lavage fluid and blood from the patients.

In vivo experiments to find high risk factors to induce AEC necrosis and further lead to ARDS evidence, can provide a more direct theoretical research foundation for the pathogenesis of ARDS.

Divided into 3 Arms ALI :Diagnostic criteria: 1.Acute onset；2.FiO2/ PaO2< 40.0 kPa (300mmHg, ALI); 3.Chest X-ray showed that the double lung texture increased, the increase of crude, fuzzy, visible diffuse patchy infiltration shadow with compensatory emphysema, for the most early performance; B. double lung field large sheet, asymmetric, edge fuzzy infiltration shadow, the most dense in the lung；4. Echocardiography, left atrial hypertension; 5.The gestational age >35 week, have maternal age cholestasis (severe), sepsis or meconium aspiration syndrome (MAS) understanding of history, and with the exception of the primary pulmonary surfactant (PS) lack of.

ARDS :Pediatric acute respiratory distress syndrome (ARDS) is a severe lung injury caused by pneumonia, sepsis, and trauma.Diagnostic criteria: 1.Acute onset；2.FiO2/ PaO2< 26.7 kPa (200mmHg, ARDS); 3.Chest X-ray showed that the double lung transparent brightness is generally lower, the glass sample, with bronchial inflatable sign, and even double lung field common density increased, the heart shadow is not clear, a white lung, as the most important performance；4. Echocardiography, left atrial hypertension; 5.The gestational age >35 week, have maternal age cholestasis (severe), sepsis or meconium aspiration syndrome (MAS) understanding of history, and with the exception of the primary pulmonary surfactant (PS) lack of；6.Need to use a ventilator.

Control group: Patients with mechanical ventilation due to external causes of the lung, no ALI-ARDS performance,FiO2/ PaO2< 40.0 kPa (300 mmHg), such as premature apnea or HIE.

Inclusion Criteria:According to the diagnostic criteria, the diagnosis was ALI or ARDS； Exclusion Criteria:Severe congenital or hereditary disease of the newborn, is clearly diagnosed as NRDS, which is caused by the lack of the primary PS。